A question for all folks with MARINE intake on board, please comment!!!

[Aksl]

Hi guys,I wonder, my chevy k1500 5.7l 1990, with vortec head swap and CSFI manifold (spider injector), is not very stable working, and i would like to change to MPFI, but i wonder:With the marine intake there is a well done instraction "pacificp" forum, so for now no questions about it. But the main question is, why did you choose marine mercruser manifold, why not to use the manifold from pontiac firebird, impala, and other models with L31 engine and exterior fuel rails, would it not be easier? Thank you all in advance.

[mihela]

The F-body cars do not use vortec heads. They are LT1 engines that use a different bolt pattern and have no provisions for a rear mounted distributor.

[1project2many]

why not to use the manifold from pontiac firebird, impala, and other models with L31 engine and exterior fuel rails

There are none that I'm aware of. L31 is truck engine with only one configuration. Marine engines use same heads as L31 so intakes will fit L31. Adapting LT1 engine is challenging and at time of first marine swaps, was equal or greater money with much additional work. Now you can get a specially made base to use the tuned port intakes but those bases weren't around several years ago.

[Aksl]

Thank you very much for explanation, I run in a Pontiac Firebird 1982 thru 1992 Heynes repair manual book, and in it, all looks the same as on my engine. Since I have changed the heads to vortec, and the entire top end (manifold, CSFI, throttle body and so on), I wanted to try on the manifold from an impala my friend is fixing... So I guess it will not be necessary, since you confirmed that bolt pattern is different, and it will be extremely difficult to adapt (if possible at all). I have another question, I contacted some boat service, and they seem to have the manifold with all of the attached equipment on, from mercruser 5.7 MPFI marine engine, but they have two different versions, the difference is in injector fitment, the degree is different, one is 45º and the other one is 90º fitment. So which one do I need, for marine intake transformation?Thank you once again for your help!

[1project2many]

you confirmed that bolt pattern is different, and it will be extremely difficult to adapt (if possible at all).

There are aftermarket parts that will adapt your manifold.
http://sdparts.com/i-23896057-sdpc-sd3816-tpi-vortec-lower-intake-baseplate.html

Marine intakes come in several versions. I have never seen them listed as 90 deg or 45 degree injector fitment but it looks like the commonly swapped manifold might be 45 degree. Can they send pictures or part numbers?

http://bertok.us/pics/l31marine/6/cpi-loomed1.jpg

http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/Marine/tunnel.png

http://home.metrocast.net/~shannen/efistuff/S10/MarineIntake1.JPG

[Aksl]

I will request the pics and part numbers. Thank you! ))

[lionelhutz]

There might be a little confusion in the thread. The pre '93 F-body intake you are referring to is called a TPI or Tuned Port Intake, which is the GM name for the intake with the runner tubes on both sides. The link to the Vortec base plate was already provided.

What PCM are you now running?

[Aksl]

There might be a little confusion in the thread. The pre '93 F-body intake you are referring to is called a TPI or Tuned Port Intake, which is the GM name for the intake with the runner tubes on both sides. The link to the Vortec base plate was already provided.What PCM are you now running?Hello, I am running the blackbox pcm, of a 1998 Tahoe.

[Aksl]

So what would you folks recommend me to go for, MPFI or TBI setup for my truck?

[1project2many]

I don't believe the blackbox is easily adapted to TBI. I would opt for mpfi.

[Aksl]

Yes, you are right, blackbox is a pain in the ass..., i mean, off course it is possible to program, the programmer i go to, is using EEPROM to tune my chip. However, even for him, he needs to make change and try the car, then again and again... (((, truly i want to swap to 411 with roadrunner, but don’t know if i will be able to tune it myself and make changes to settings, how difficult it is and what knowledge i must have. With EEPROM i am sure i am not capable of doing it!!! ((

[Aksl]

Found this manifold: http://www.michiganmotorz.com/mercruiser-volvo-penta-crusader-intake-manifold-2008-current-p-4576.html, if i don’t get the used one, from the service that found me two different manifolds, will probably start saving for the one from the lint, nowadays with the FX rate, plus shipping costs (and i guess it weights a lot), the prices in $ really bite...

[brian617]

That manifold has the 4 bolt drive by wire throttle body. Might be a concern there as the Vortec and LS cable are three bolt.

[Aksl]

That manifold has the 4 bolt drive by wire throttle body. Might be a concern there as the Vortec and LS cable are three bolt.Yes, you are correct! Thank you!, I didn't notice it, all thaw it comes whith it's own throttle body, but don't know if it will work. Thank you for pointing this out for me, I have to be more attentive!

[Hog]

The L31 uses the 3 bolt t-body. If you want to retain your stock cruise control along with the stock you need to run a t-body spacer to clear the passenger side fuel rail, or slightly bend out the tab on the L31 throttlebody. The Ramjet intake can be had as well, but the Marine Intake is the most complete, easiest conversion there is. This is all covered in the Marine Intake Bible. point #5. http://www.pacificp.com/forum/viewtopic.php?t=317 Why are are you wanting the MArine Intake, it does a dd a bit of power, but not worth doing the swap for that alone? The only reason I did it was to be one of the first to do it. peace Hog

[Hog]

Bench mockup of my marine intake http://bertok.us/pics/l31marine/hog/marine_mockup.jpg peace Hog

[Aksl]

Hello Hog, well, concerning the question why, I`m really feadup with the CFSI system, i cant beat it, i had a bad spider, some of the balls in the clawns where bad and were getting stuck, so i bought another spider, of a working car, that was sold by parts, the body was so rusted, so the guy startied selling it by parts, he didn`t even want to dell the engine buy parts, wanted to sell it as a working peace with gearbox, but finaly sold me the spider, so since i had trouble with tuning my PCM, i thought that the problem was there, but no, it the damn spider again. I hate this spider system, and want a real MPFI, that is why i want to do a manifold swap, i would like to have external fuel rails, and direct external MPFI on my car. I dont know if I can make TBI work with blackbox, i could go for TBI, and really confused with a question of what is better, and more stable and reliable.

[Aksl]

nice

[Aksl]

My car is working now, and can drive, but it does not put the rpm up when cold, and on the nutral or just standing still, it keeps barking, the rpm i mean, unstable...(((

[Hog]

One thing about the stock CSFI setup is that the lack of a true fuel rail, allows for optimum injector targeting inside of the intake runner. With the Marine Intake and any other intake that uses a real fuel rail, the injector is more apt to have a sharper angle of incidence (angle at which the fuel steam strikes the port wall) than the stock CSFI. That is about the only performance advantage to the CSFI unit. Just so you know, the CSFI does indeed fire in true sequential injection mode, injector firing is based upon intake valve position. And yes, it doesn't have a conventional fuel rail. I have some spider parts in my shop. Let me see what I have and if I have a complete good set, I'll send it to you. The CSFI spider is a pain in the ass esp because its installed INSIDE the intake plenum, but once it is working it is pretty reliable. The reason why I asked why you wanted a marine intake is because it costs quite a bit of money, for only slight gains on its own. IMO It would be better to buy a brand new MPFI spider setup with the actual Multec mini-injectors at the end of each spider leg. I have run into issues myself where I blame the spider assembly simply because it has such a bad name on the internet, but then I discover that the spider wasn't to blame. Out of all of my Vortec 350 CSFI trucks, Ive only had an issue with the spider system ONCE. Just so you know, there is a lower intake manifold that will fit your Vortec L31 heads, and will allow you to bolt on a 1985-1992 TPI unit that were used on the Camaros/Firebirds and 85-1991 Corvettes. Its a Vortec to TPI lower baseplate. I actually used one of these on a 1085 IROCZ with a Vortec 355 engine and LT4 hotcam kit. http://sdparts.com/i-23896057-sdpc-sd3816-tpi-vortec-lower-intake-baseplate.html Then you would wire up your 8 injectors to the blackbox PCM, and run everything just like the Marine Intake. or http://sdparts.com/i-19976057-chevrolet-performance-12489371-manifoldint.html Which is the actual intake manifold part of this kit (use this for a picture of intake)http://sdparts.com/i-19966136-chevrolet-performance-12498032-injection-pkgelek-fuel-ramjet-350.html Find a Ramjet intake and use it, these will work on the L31. Find one used, in fact finding any of these parts used will save you lots of money. This intake allows you to use TBI on Vortec heads, but I don't suggest using TBI. Id way rather run CSFI than TBI. http://sdparts.com/i-19976058-chevrolet-performance-12496821-manifoldint.html peace Hog

[Aksl]

Hello Hog,Thank you for giving so much usefull info! Well, I guess the cheapest way to go, is to get a modified CSFI spider injection module, with little injectors at the end of each tube of the spider. Of course I would like to have an external fuel rail, for ease of fixing and working on in future, not to have to unscrew all of the manifold to get to injectors... And as I understood you correctly, you would recommend to go with modified csfi spider, or marine manifold, but not tbi.., I now curious of how to choose the right size injectors for my set up, not to make a mistake and just throw away cash..

[Hog]

Yes, if you are going to stick with a 350 or 383 I'd probably just stick with the Multiport Flexible Injection (MFI) spider(one with the little Mini injectors at the end of the spiders legs) or marine intake, or some other intake manifold that works on Vortec heads. In my opinion TBI would NOT be a choice on this build simply because you are already using a MPFI PCM. Just so you know, the stock CSFI spider flows at 23.1 lb/ht @ the Vortecs 63psi of rail pressure(or about 19.1@ 43.5 psi, or about 22.2 lb/hr@58psi of fuel pressure). I am running the stock Marine intake injectors which Ive had flow tested at 25lb/hr @ 43.5psi(3BAR) or 28.9 lb/hr@ 58psi(4BAR) of fuel pressure. This calc allows you to figure your Injector Flow Rate at whatever fuel pressure you set your FPR to. http://www.csgnetwork.com/fiflowcalc.html You just don't want to go too big so that you have idle instability. Here is some stock GM GEN 3/4 SBC injector info http://ls1tech.com/forums/fueling-injection/1571836-lsx-family-injector-flow-rate.html This is the MFI conversion http://www.fourwheeler.com/how-to/1012or-csfi-to-mpfi-vortec-engine-fueling-fix/ Here is a GM Powertrain marine Vortec 350 brochure from 2013. http://www.gmpowertrain.com/2013_pdf/FHR_REV_5.7_Marine_010713.pdf And here is the GM document for the CSFI to the MFI conversion done to 1996-2002 vehicles in California under warranty xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx. Campaign – SCPI Warranty Extension File In Section: 06-Engine Emissions Bulletin No.: 99066F Date: March, 2003 SPECIAL POLICY SUBJECT: 99066F – SPECIAL POLICY ADJUSTMENT – SEQUENTIAL CENTRAL PORT FUEL INJECTION (SCPI) FAILURES IN CALIFORNIA ONLY (YF5 EMISSION EQUIPPED) MODELS: CERTAIN 1996, 1997, 1998, 1999, 2000, 2001, 2002 S/T, M/L, C/K, G, P, W4/NPR TRUCKS AND 2003 NPR TRUCKS EQUIPPED WITH 4.3L (RPO L35 – VIN CODE W OR RPO LF6 – VIN CODE X), 5.0L (RPO L30 – VIN CODE M) OR 5.7L (RPO L31 – VIN CODE R) ENGINE AND CALIFORNIA EMISSION EQUIPPED (RPO YF5) This bulletin is being revised to add the 2002 and 2003 model years to the SCPI Special Policy on certain S/T, M/L, C/K, G, P and W4/NPR truck models. Please discard Special Policy Bulletin Number 99066E, dated February, 2003. CONDITION Some customers of 1996, 1997, 1998, 1999, 2000, 2001, 2002 model year S/T, M/L, C/K, G, P, W4/NPR trucks and 2003 NPR trucks, that are registered in California, equipped with 4.3L (RPO L35 and VIN Code W, or RPO LF6 and VIN Code X), 5.0L (RPO L30 and VIN Code M) or 5.7L (RPO L31 and VIN Code R) engine, and California emissions (RPO YF5), may experience a “Service Engine Soon” light, misfire, rough idle or hard start due to a deposit build-up on the Sequential Central Port Fuel Injector (SCPI) poppet valve(s). The deposit build-up may cause injector poppets to stick closed. Certain fuels have been found to interact with the SCPI system to cause the deposits. SPECIAL POLICY ADJUSTMENT This special policy covers the SCPI failure condition described above for a period of ten (10) years or 200,000 miles, whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. The repairs will be made at no charge to the owner. This special policy applies ONLY to repairs requiring SCPI system servicing, injector cleaning and/or MFI assembly replacement of the SCPI system. The customer should not be charged for performing a system check when it is determined that the SCPI system is not the cause of a customer complaint (labor operation T5532 is provided to submit claims for such system checks). Any additional necessary diagnosis and repairs that are not related to the SCPI condition are not covered by this special policy. The customer should be informed that any further service that is not covered by new vehicle warranty will not be covered by this policy. VEHICLES INVOLVED Involved are certain 1996,1997,1998,1999, 2000, 2001, 2002 S/T, M/L, C/K, G, P, W4/NPR and 2003 NPR model vehicles, registered in California, equipped with 4.3L (RPO L35 – VIN Code W, or RPO LF6 – VIN Code X), 5.0L (RPO L30 – VIN Code M) or 5.7L (RPO L31 – VIN Code R) engine; and California emissions (RPO YF5). This Special Policy covers all vehicles within these model years, with these engine and emissions RPO’s. Parts required to complete this special policy are to be obtained from General Motors Service Parts Operations (GMSPO). Please refer to your “involved vehicles listing” prior to ordering parts. Normal orders should be placed on a DRO Daily Replenishment Order. In an emergency, parts should be ordered on a CSO = Customer Special Order. IMPORTANT :Isuzu Parts Ordering: In order to comply with the 10-digit Isuzu part numbering system, Isuzu dealers must add an “8” to the beginning and a “0” to the end of the listed 8-digit part numbers when ordering parts through AIPDN. Customers will be notified of this special policy on their vehicles by General Motors (see copy of typical customer letter included with this bulletin – actual divisional letter may vary slightly). SERVICE PROCEDURE System Check: Use strategy-based diagnoses listed in the front of the Driveability and Emissionssection of the service manual. If the SCPI system is operating properly, inform the customer that the vehicle does not have the condition listed in the owner letter. If poor driveability conditions persist, inform the customer that any further diagnosis and repairs will be at their expense if the vehicle is outside the parameters of the new vehicle warranty. SCPI Injector Cleaning Procedure: If diagnosis leads to sticking poppet nozzles, use the service procedure from Service Bulletin 00-06-04-003B to clean the SCPI poppet nozzles. Please note that the service bulletin term for SCPI is Central Sequential Fuel Injection (CSFI), but is referring to the same fuel system assembly. If the poppet nozzles have previously been cleaned and the sticking condition has reoccurred, refer to the correction paragraph below. SCPI Fuel Tank Fill Pipe Assembly for 1997-99 M/L Van and 1999 – some 2000 C/K Truck: with 4.3L, 5.0L, 5.7L engines and built prior to listed VIN/Production dates on Service Bulletin 00-06-04-018: If diagnosis leads to sticking poppet nozzles on these models, use the service procedure from Service Bulletin 00-06-04-018 to replace the fuel tank fill pipe assembly, if this procedure has not been performed previously. Previous service procedure can be verified by checking GMVIS for Labor Operation L1065 on “M/L” trucks with replacement part number 15050573; or Labor Operation L1065 on “C/K” trucks with replacement part numbers 15747585 or 15747588. Correction: If, after cleaning the SCPI poppet nozzles, the normal service manual diagnosis still indicates that the SCPI is the cause of the customer complaint, or if the injectors have previously been cleaned and the vehicle has again experienced sticking poppet nozzles, refer to Service Bulletin 00-06-04-003B and replace the SCPI fuel assembly with the MFI fuel assembly. Please note that the service bulletin term for SCPI is Central Sequential Fuel Injection (CSFI), but is referring to the same fuel system assembly. For vehicles repaired under this special policy, submit a claim with the information indicated. CUSTOMER REIMBURSEMENT Customer requests for reimbursement are for any previously paid repairs to, or replacement of, the Sequential Central Port Fuel Injection (SCPI) system. Repairs must have occurred within 10 years of the date the vehicle was originally placed in service, or 200,000 miles, whichever occurs first. The requests are to be submitted within two (2) years of the date on which the repair was paid or within two (2) years of the date of this Special Policy Bulletin, whichever is greater. When a customer requests reimbursement, they must provide the following: – Proof of ownership at time of repair. – Original paid receipt confirming the amount of unreimbursed repair expense(s) (including Service Contract deductibles), a description of the repair, and the person or entity performing the repair. Customers from the State of California, must submit requests for reimbursement directly to (Divisions) per instructions in the owner letter. If the work was done by someone other than a GM dealership, the amount of reimbursement will be limited to the amount that the repair would have cost GM to have it completed by a GM dealership. xxxxxxxxxxxxxxxxxx peace Hog

[Hog]

I'm not sure why my posts are all squished together, it make sthem impossible to read. Here is the GM MFI conversion part for sale at Rock Auto ACDELCO 2173029 {#89060440} GM Original Equipment $293 US dollars for the brand new ACDelco GM GM unit http://www.rockauto.com/en/catalog/chevrolet,1999,k2500+pickup,5.7l+v8,1353350,fuel/air,fuel+injector,6224 peace Hog

[Aksl]

Hi Hog, want to thank you for the link to direct part, has just ordered it. Thanks mate! )))

[Kitch]

Hi Hog,
I had the squished text problem, I fixed it by going into "Settings/My Settings/My account/General Settings"....then scroll down to "Miscellaneous Options/Message Editor Interface:" and I changed from Enhanced interface to Standard Editor.
See if that works for you :-)

[Aksl]

Hello everyone, have a question of compatibility of brake booster, may be some one can give a hand on this, i found a hydro booster of brakes on eBay, my Chevy Silverado 1990 has vacuum booster and want to swap, will this booster fit me? Here is a link: http://www.ebay.com/itm/New-OEM-Power-Brake-Booster-ACDelco-178-0685-Fits-03-06-Escalade-Suburban-Tahoe-/131368591132?hash=item1e962d9f1c:g:2sMAAOSwxp9W19~ G&vxp=mtrThank you in advance!Or this one, its a little cheapper inc. shipping: http://www.ebay.com/itm/Power-Brake-Booster-Hydraulic-w-o-Master-Cylinder-Cardone-52-7393-Reman/302020313468?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%2 6asc%3D40832%26meid%3D7da017ec4db941faa57ca5602e3c b871%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D2519 98588781

[Eds]

The power booster you are looking at appears to be the wrong one for your application. I believe this would be a better choice.http://www.ebay.com/itm/Power-Brake-Booster-Hydraulic-w-o-Master-Cylinder-Cardone-52-7328-Reman-/262432128099?fits=Year%3A1990%7CMake%3AChevrolet%7 CModel%3AC2500%7CSubmodel%3ASilverado%7CEngine+-+Liter_Display%3A5.7L&hash=item3d1a2c7c63:g:gqMAAOSwYmZXMxXc&vxp=mtr

[Aksl]

Thank you for the link Eds, the one you sent to me via link, willdo for my vacuum boost to hydro boost upgrade correct? thanks once again...

[Eds]

Thank you for the link Eds, the one you sent to me via link, will do for my vacuum boost to hydro boost upgrade correct? thanks once again...Yes I believe so.

[Aksl]

Thank you!

[Aksl]

Hi everyone, so, i bought and installed MPFI spider injection on my track, could feel the difference straight away, it started working more powerful i would say, even sound. While installing, i noticed that when i wanted to drop fuel pressure before taking the fuel line of, the was no pressure in the line, so i gues, after shuting of the engine, fuel just doesnt stay in the line and dropes to tank straight away. I have a taiwan after market fuel pump installed, 280l power. Dont know if that may be the cause, or something else, but i still have the idle problem i described earlier. The engine works, but sims to may be not inject onse in some cycle.. May be its the pump, may be the PCM, dont know. If anyone have any idea, would appreciate!Here is two videos i recorded, you can see and hear, from the exhast, how it just stalls for a second in every some of a cycle.https://youtu.be/kCDyOP1qC6U https://youtu.be/HzucmfJvTcM

[Hog]

Good day sir.

In your 1st video, I noticed that while viewing your clear distributer cap, that we are able to see sparks continuously while the engine idle is cycling. That tells me, that your issue is NOT ignition/coil related. But its tough to 100% verify this in your video, so since its in front of you, make sure that your coil is firing 100% of the time to eliminate your ignition as the cause of this issue.

What is your fuel pressure doing while this is happening? Since you have installed a nice brand new FPR, your fuel pressure should sit there and idle at around at least 58 psi, and if you shut off the engine and measure the fuel pressure WITH THE FUEL PUMP RUNNING, like when you 1st cycle the key and the fuel pump primes the fuel system for 2 seconds before you start the engine, it should read between 60-66 psi. The Key On ENgine Off pressure should be the same as the pressure you would get if you put you taped you fuel pressure gauge to the windshield and held the throttle WIDE OPEN. Wide open throttle and engine off fuel pump running pressures should be the same because the Fuel Pressure Regulator is seeing almost 100% atmospheric pressure therefore does NOT need to reduce fuel pressure like it does when the FPR sees engine vacuum like it does when the throttle is closed or partially open.
If you hook up a fuel pressure gauge and you see pressure fluctuations that follow the up and down cycle of your idle rpm, then you may have found your culprit.
What is the idle speed? Seems awfully fast.

Are you running the 2 Precat(O2 sensors positioned in between the exhaust manifolds and the catalytic converters) O2 sensors and the 2 Postcat(O2 sensors located after the catalytic converters) OR just the 2 Precat O2 sensors? Does your PCM go into Closed Loop?

It would be great to see some data from your IAC Idle Air Controller.


In regards to your lack of fuel pressure after your truck has sat for a while. The system should hold at least some pressure for hours after you shut the engine down. It can only bleed away from a)the injectors b) the Fuel Pressure Regulator but both of these are brand new now that you have completed the CSFI to MFI retrofit. That leaves you fuel pump. A good pump will not let fuel pressure bleed back into the tank. Of course this assumes solid, leak free fuel lines and plumbing. So long as it starts, this isn't an issue I would worry about.

Sitting there at idle is one thing, but what is the engine doing at idle in gear? Does your idle decrease as the engine warms up? It should.

What are you plans for this beast? Do you plan to daily drive it? What do you desire from this engine?

This all could be a calibration issue as well. It would be nice to have a bone stock PCM for you to diagnose with.

peace
Hog

[Aksl]

Hello Mr.Hog, nice to hear you again! Well concerning the distributer and my see through cap, you are correct, I can now see all of my sparks, and they are all good, as well all no faulty code from the engine. I thought to check my wires and spark plugs, all thaw the spark plugs are new, and the wires have been checked before, but i got that out of my head, checking them again, because as you can see the misfire goes once in a cycle, shutting all the cylinders, so the engine every some cycle, just chokes all cylinders and continues running, then again and again, but the distributer, distributes the spark continuasly. Fuel pressure has been checked as well many times, and it is correct at all working modes, except when i shut the engine it just disappears. No leaks from fuel line, injector and fuel pressure regulator are new, so i'm pretty much sure it's the fuei pump, that does not hold the pressure in the system after shutting the engine off. Anyway, the fuel pump cant be the issue, due to steady pressure while the engine is up and running.I have no catalytic converters, i have straight line out exhaust from both sides, they are not joint together at any point, so have just two 2O sensors, and no EGR, cut as well, in the pcm all that set to run with this setup.IAC Idle Air Controller, is the main thing now i'm looking in to, the second is the problem with the PCM tune. It it hard for me to find a stock pcm from a working car, that has same setup as mine (( So, when thecar is on a run, there is no such a issue, as long as i am continuing to accelerate, as soon as i take my leg off the pedal, here you are again.What is my plan for my track, well, long distance runs around russia, hunting, motocross, and continuing to restorate, sound, leather, boxes for tools implemented in to trunk sides, even folding in to floor seats, may be, to carry more than 2 people and the driver..)) dont whant to sell it, i bought it from a friend, who bought it from the street, we just so it standing for 2 years on breaks in the hood, found the owner and got it, becouse its a pitty when somethong like this truck is dying on the street, got it up running, then my friend had a problem with cash, due to credit, i bought it, and if i sale it, than only back to him))) anyway i doubt it, and he can take it any time, if he needs. That's its story.

[Aksl]

Ow yes, and it does drop the idle down, when warms up, all thaw it was set to a higher idle by the PCM, becouse when it set to normal, 0.8 it shuts of often because of this issue.

[Aksl]

Dam, I don`t know why, but when I type a message, replying to threads on this forum, and move to new paragraph, or make big spaces, or start from new line, the forum does not recognize it, and just splashes all together, one after the other, really annoying !

[1project2many]

In my experience the "Black box" pcm like you have installed doesn't idle well in non-stock configuration. In some cases it also does not seem to compensate fuel delivery properly for voltage fluctuations experienced during idle. If system voltage crossing 12-12.5V during idle, finding a way to stabilize system voltage can be enough to reduce idle speed fluctuations. Using a "jump pack" connected to the battery as a diagnostic test can raise system voltage just enough for idle to smooth out. After checking all the basics, I have found that watching the idle parameters such as desired speed and IAC position on a scantool or laptop can help diagnose whether or not the programming is causing the problem. Adjusting the tables involved in spark based idle speed control and the closed loop idle speed control PID loop can help reduce this tendency.

[Aksl]

Hi mr.Hog, well i didn`t know that, I`m really confused, there are alot of people who have made swap like mine (TBI to Vortec), do they all run in to the same problems as me. Didn`t anyone right a guide for such a swap and what to wait from it, what under water stone you will run in to, and how to ovecome them.
Any way, I have invested alot in this truck, will do more, untill i get it perfectly on the go. I planned to get the 12200411 PCM-based RoadRunner for a swap, it`s really expensive thaw 600$, plus i need a program for it, and that is another 250$, may be then i can get my PCM well tuned and runing properly with my setup.
http://www.moates.net/roadrunner-ls1-realtime-emulation-pcm-p-105.html?cPath=95

[1project2many]

I'm sorry if I have forgotten the details of your swap. Is your engine the same as a stock Vortec engine?

[Aksl]

Hello, no no no, it's not stock at all! Its a 1990 chevy silversdo z71 short bad step side 5.7l tbi, with engine rebuild, kb pistons 0.25 bored, head swat to vortec with all top (intake manifold, injector, and so on), spider acdelco mfi, and an after market cam (comp cam 08-467-8), and uder hood wiring, blackbox pcm, from same 1998 vortec Tahoe as everything else. PCM has been tuned, the cheap was remooved, and flashed several times, a bracket for the chip was installed in PCM, so now it can be removed any time and reflashed via EEPROM programmer.