my 454 swap

[black dawg]

Swapped in a 74 454 that I added a stock vortec cam to.
Using 92 454 throttle body. computer is 7747 prom is ANTY, but is a hypertec. I got the number for the prom using my scan tool.

The problem is the idle speed ends up at 1000-1100. I do the whole min set procedure, my book tells me 700 in gear. When I finish the procedure and restart idle speed is slightly higher than min, with IAC counts in the 35-40 range. A few restarts later, the idle creeps (1000-1100) up even though IAC is at 0. And it is completely seated. There are no vac leaks and I have tried backing the timing down from 4 deg and it doesnt really help.

[JeepsAndGuns]

If the IAC goes to zero counts, then it sounds like the throttle blades are too far open. They usally wont do this untill engine is warm. I did this when I was new to tuning. I guess I had set the min idle when the engine was not warm enough. As for a long time I couldnt get it to go to 650 rpm idle like I had set, I then noticed my iac was at zero! Reset my min idle and all was well after that.

[EagleMark]

ANTY has a flat 750 RPM idle for all temps in "IAC - Desired C/L Idle Speed" I didn't look for any other changes.

To do the Min Air set procedure motor has to be totally warmed up even rev the engine after warmed up for a minute if you can't drive it. Then has to be in Closed Loop. If your getting 0 IAC counts and 1000 RPM with no vacuum leaks then the throttle blades are open to far.

Also ANTY has been superceeded twice, once to ATPX, then to final version of AZFT. I don't know why it was updated by GM but it may have issues, twice!

[black dawg]

well I will wait till the exhaust is done up before I mess with it anymore. The o2 is fresh and is the same one I used with the 350. Thanks for the replies

[EagleMark]

Just looked at that bin some more and it is an Open Loop idle bin. Will have to make some changes to be closed loop idle...

[Nasty-Z]

Check the throttle shaft play in the TBI , the BBC TBI's are notorious for elongating the holes the throttle shaft rides through , causing the exact problem you describe.

As others have said , if the IAC counts are at zero , un metered air is entering somewhere or the throttle blades have been opened up too far .

Does it do the idle creep with and without your scan tool hooked up to the ALDL port , some of the different scan tools I have come across would cause an idle creep if left hooked up to monitor data , never could really explain it ........

TOM

[black dawg]

Check the throttle shaft play in the TBI , the BBC TBI's are notorious for elongating the holes the throttle shaft rides through , causing the exact problem you describe.

As others have said , if the IAC counts are at zero , un metered air is entering somewhere or the throttle blades have been opened up too far .

Does it do the idle creep with and without your scan tool hooked up to the ALDL port , some of the different scan tools I have come across would cause an idle creep if left hooked up to monitor data , never could really explain it ........

TOM
The scan tool does have a small effect on it. I have seen that on some of the tbi stuff where with the scan tool connected they idle 1000+.

[black dawg]

Well as an experiment I put my 350 prom in to see what the idle will do, and it works just like it should.

I drove it some with the 350 prom, and there was some very slight lean sags till the block learn crept up, and after that it runs very good. wot is actually richer with the 350 prom (.960 vs .900)

What is the range of blm, the 454 prom while driving runs about 140-160 blm, and the 350 prom runs 150-180.

[EagleMark]

The scan tool does have a small effect on it. I have seen that on some of the tbi stuff where with the scan tool connected they idle 1000+.That usually means it is in ALDL mode, idle RPM is set to 1000. I beleive it also changes spark too...

The 350 prom is just totally differant then a 454 prom.

Like I said above the 454 chip you have is open loop idle and been updated twice. The 350 prom is idling correctly because it's a closed loop idle prom.

[black dawg]

would it be better to tune on the 454 chip? can it be made closed loop idle? Or would it be easier to just make the 350 chip match the 454 engine.

[1project2many]

Swapped in a 74 454 that I added a stock vortec cam to.
Cam from 96 or newer engine? Did you add roller lifters as well?



Does it do the idle creep with and without your scan tool hooked up to the ALDL port , some of the different scan tools I have come across would cause an idle creep if left hooked up to monitor data , never could really explain it ........
Because some scanners use "10k" or "ALDL mode" which enables different settings in the calibration for testing and diagnosis.

Old trick for setting minimum air is to cut a strip of paper 1/4" wide then close between throttle plate and bore at 90 deg to shaft. Proper setting gives slight drag when paper is pulled out. Do when engine is warm for best results.

[black dawg]

Used retrofit rollers and the gen 6 timing set and cam retainer.

[JeepsAndGuns]

would it be better to tune on the 454 chip? can it be made closed loop idle? Or would it be easier to just make the 350 chip match the 454 engine.

If the 454 bin you have has been superceded twice, and the 350 bin you have runs significantly better, then I (just me personally) would tune that bin.
Just my $0.02 worth.

[EagleMark]

I'd agree with JeepsandGuns if that was the only 2 bins I had. But we have plenty of 454 bins to start with including the AZFT it was superceeded to.

Yes you can make that a Closed Loop Idle bin but then it has been superceeded twice, so I'd still start with a differant one like the AZFT it was superceeded to.

I've also used the AZFT a few times for a starter tune and had no issues.

[black dawg]

Well, I got the 454 prom to work for me. It seems my balancer has slipped, so timing was way to advanced. I also lowered my fuel psi from 15 to 12 and this leaned it out to where it works. I think these injectors are to sloppy, because I have never seen that little of pressure change affect the o2 as much as this did. The injectors do look drippy at cold start.

what would you expect to see for warmed up open loop idle o2 readings at 3500ft? I am .89ish
what would you expect for WOT? I get from .96-1.0

[gregs78cam]

Well in a TBI dropping from 15 to 12 psi is about a 10% difference in flow. I would think an OL idle should be close to .50 maybe .60, ideally .45, but that will depend on your VE table. 0.89V at idle sounds really rich. .96 - 1.0 at WOT sounds only slightly rich, but a NBO2 is not even close to being useful for WOT tuning IMHO.

[EagleMark]

Well, I got the 454 prom to work for me. It seems my balancer has slipped, so timing was way to advanced. I also lowered my fuel psi from 15 to 12 and this leaned it out to where it works. I think these injectors are to sloppy, because I have never seen that little of pressure change affect the o2 as much as this did. The injectors do look drippy at cold start.

what would you expect to see for warmed up open loop idle o2 readings at 3500ft? I am .89ish
what would you expect for WOT? I get from .96-1.03 psi is not a lot on MPFI when base pressure is 43.5 but 3 psi is a lot on a TBI system based on 13 psi.

The O2 readings your showing are rich, but at 3500 feet I would expect that.

Narrow Band O2 sensor is only measuring 1 volt and designed to be about .45 for 14.7 to 1 AFR so higher is richer and lower is leaner. But it is only accurate around .45 and ECM keeps it swinging back and forth there.

Wide Band O2 sensor uses 0 to 5 volts so it is 5 times more accurate and designed to measure AFR, not just keep it at 14.7 to 1.

Having these old injectors serviced is great money spent. If you don't have someone local look for Mr Injector. I've seen between 5 and 13% difference in injector flow rates from service.

With the cam change your only option for great running engine is a chip tune. If you don't have equiptment needed, then you've really done all you can. You need to get these mechanical issues in order before tuning anyway. If you want to get into tuning then buy equiptment and spend some time. If you don't want to spend time and money then buy a cable to record data and you can buy a tuned chip. Either option is about $150. to do it right.

[black dawg]

Thanks for the replies and info guys. What do they do to service an injector?

I will most likely get into tuning myself, just have to save up a little. I spent way to much on this project already.

[EagleMark]

They test the electrical side first, then run cleaning fluid through them at high pressure with ultrasonic vibration. I've watched the service and can see the difference in spray pattern. Pretty cool!

[black dawg]

Well now I am really confused. I decided to try my motorvac injector cleaner on this thing, and it did make the injectors much cleaner. What I did learn though is that I had 30psi fuel pressure. When I checked the other day, I checked at the filter and with a different adapter to my gauge, and it showed me 15psi. So now checking fuel psi at the throttle body (verified with 2 different gauges) I have 30 psi. I have been having problems with it being rich, so I lowered it way down to 19psi, And it will hardly idle it is so lean. Is lean accross the board at 19psi. I played with the pressure some more, and it takes 22-23psi to make it run right. I checked the injectors numbers and they are the early 454 injectors.

I put in a better pump before I did the swap, so that I would have some room to pressure tune if I needed to.

Am I overlooking something really stupid, or have these injectors been screwed with?

[black dawg]

I should add that I got this throttle body from my brother in laws truck, And it never ran right. Had some lean issues and eventually burnt valves. It was a 92

will the pre-94 regulator make over 20psi? I basically cut the spring in half to get the pressure under 20psi.

[EagleMark]

Something is wrong? Fuel pressure gauges are notoriously inaccurate! Your pressure should be almost identical after filter and at TBI unit.

What injectors do you have?
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?81-GM-Injector-size-color-and-part-numbers

If you had to cut a spring in half I'd say you just cut a good high pressure spring in half that came on later BB TBI units that run about 30 PSI... if numbers you are at now are accurate you have enough pressure for early BB injectors for about 500HP and should be pig rich at idle with stock chip.

Or you have a restriction in return line? Return line should be 0 PSI anything above that raises feed side by same amount.

[black dawg]

the injector numbers are 1708434. I checked at tb and filter, using the same adapter and 2 different gauges and saw 30 psi. When I saw 15psi at the filter I was using an adapter I hadnt used before, and I guess something must have been wrong with it. The spring I cut in half was out of a 350 tb.

When fuel pressure was 30psi, it was pretty dang rich idling and felt all around flat.
Right now I have fuel pressure is at 22psi, And it needs a hair more. I will check for a return line issue, because it seemed pretty weird how far I had to alter the pressure regulator to get under 20psi.

Why do these injectors (with numbers that match low psi 454 injectors) want this much pressure.

[EagleMark]

The number you gave does not exist on list? But if you missed a 0 and it is 17084304 then it should not need that much pressure! Something is wrong?

[black dawg]

yep, left out that zero. right now, with pressure at 24, OL idle is .75 and WOT is .90.

with pressure at 22psi, idle was .20 and WOT was .87.
I got 24psi by putting the regulator back to stock (the way it was removed from the pickup).

I am going to find some other early 454 injectors to try.

[Six_Shooter]

I have found recently, that some engines, especially big blocks will act a lot like diesels, where fuel is concerned.

On an Olds BB, I can change idle RPM by as much as 600 RPM just by richening up the idle.

[black dawg]

well I have been running it at 23psi and it works pretty good, not perfect but ok. BLM is in the 120-140 range and seems to be inconsistent with with load or rpm.

[black dawg]

What is the other smaller removable chip in the 7747 for?

[EagleMark]

It's the Netres or Limp Home chip.

[black dawg]

The number you gave does not exist on list? But if you missed a 0 and it is 17084304 then it should not need that much pressure! Something is wrong?

Do you think it could need that much fuel pressure because of the engine mods and a stock prom? I am not finding anything wrong.

[EagleMark]

well I have been running it at 23psi and it works pretty good, not perfect but ok. BLM is in the 120-140 range and seems to be inconsistent with with load or rpm.Yes it will be inconsistent because you raised pressure and did not calculate BPW. It is doing exactly as I have tested, gone rich at idle and low RPM/Load and lean at high RPM/Load.


Do you think it could need that much fuel pressure because of the engine mods and a stock prom? I am not finding anything wrong.23 PSI on those 76 PPH injectors will support about 364 HP. I doubt very much a stock 454 engine with a stock vortec cam would be close to that?

[black dawg]

What I meant was, this thing will hardly run because it is soo lean with fuel pressure under 20psi. Is this because of the cam.
Oh and feels under 300hp to me.

[EagleMark]

Without my hands on it I'm not sure? Or at least a data log...

Usually bigger cams want less fuel at idle and more high RPM/Load. At your elevation... I loose track of everyone... you were at 3500 feet right? That would also be less fuel at idle, but I don't know why a stock vortec cam would effect idle like this?

If it's running and driving good then use it. You've really done all you can to make it work without data logging and tuning a new chip.

[jameslleary]

Not for nothing, but, you may want to check your injectors, some of the 454's used 40pph injectors, along with a higher pressure TPI pump...just throwing ideas.

[black dawg]

Well I am getting closer on this thing, had some crappy fuel pressure gauges throwing me off. First two gauges read 22 and 23 psi, and third reads 15psi. anybody have a favorite gauge to reccomend?

I have noticed that the blm number at idle varies instead of just showing 128. Does this mean it learns an idle blm even though it is an open loop idle bin? Drove this thing on the highway tonight for about 30 miles, and when I came to a stop, it stayed closed loop for about 2 min. Was it supposed to do that?

[black dawg]

Also ANTY has been superceeded twice, once to ATPX, then to final version of AZFT. I don't know why it was updated by GM but it may have issues, twice!

I have gotten this thing mostly sorted, (no tuning yet) but I am curious if the issues I am having is because of this prom. The prom I have is anty, and has been modified by hypertec before I bought it used.

What would it cost me to get somebody to burn me an updated or better stock prom for this thing. I have decided that I wont be happy with this thing without some tuning being done, but hate to start with this prom if it is a pos.

[EagleMark]

would it be better to tune on the 454 chip? can it be made closed loop idle? Or would it be easier to just make the 350 chip match the 454 engine.You can, I use ASDU and make it a 7.4L


What is the other smaller removable chip in the 7747 for?Netres, is it correct for your 7.4L?


Do you think it could need that much fuel pressure because of the engine mods and a stock prom? I am not finding anything wrong.No something is wrong.


I have gotten this thing mostly sorted, (no tuning yet) but I am curious if the issues I am having is because of this prom. The prom I have is anty, and has been modified by hypertec before I bought it used.

What would it cost me to get somebody to burn me an updated or better stock prom for this thing. I have decided that I wont be happy with this thing without some tuning being done, but hate to start with this prom if it is a pos.Post a data log so I can see what it is doing?

[black dawg]

On the netres chip, how do I tell? Does it matter?

On the fuel pressure, I dont believe my gauge, but adjusted fuel pressure to where blm is reasonable. gauge shows 22psi and wont hardly run below about 17 psi.

Not set up to data log at this point.

What I would like to do is get a better prom, and then if it still isnt satisfactory, I am hoping the better prom is is closer/easier to tune for somebody.

[EagleMark]

Is the netres chip the one that came in ECM with the truck?

I can tune whatever is needed and start with a better PROM, but without data logs it's just an educated guess, not a tune!

You really need to figure out what the fuel pressure is. If the motor is stock and the injectors are correct BB then 13-14 psi is GOOOD! 12 is OK...

How far in Montana are you from Coeur d'Alene Idaho?

[black dawg]

I am in Missoula.

I have been working out things that needed straightened out, next is fuel pressure.

What I would really like to do, after I have everything the way I want it is, to leave the thing with you for a week or two.
Is that possible?

I am avoiding getting into tuning myself, because I am very picky, (when I know that I could make something better) and learning tuning to the level that I would feel satisfied with myself would take more spare time than I have.
I would much rather have someone that knows what they are doing just make the thing work right.

[black dawg]

on the netres chip, the 454 prom came with one, but I dont remember if I used it or left the original in the 350 ecm (that I am using).

[EagleMark]

I am in Missoula.

I have been working out things that needed straightened out, next is fuel pressure.

What I would really like to do, after I have everything the way I want it is, to leave the thing with you for a week or two.
Is that possible?

I am avoiding getting into tuning myself, because I am very picky, (when I know that I could make something better) and learning tuning to the level that I would feel satisfied with myself would take more spare time than I have.
I would much rather have someone that knows what they are doing just make the thing work right.Sure it's possible!

Tuning can become an obsession, it never ends, you learn more and tweak more... in my spare time I spend every minute tweaking my own rig... learning new rigs... etc...

I'm not really sure how to check the netres, I'm very careful to use correct ECM with netres. It's really only cruicail for catstophic failure and has limp home stuff on it.

[black dawg]

I will let you know when I am getting closer on this thing, I am considering some engine mods and a 4l80, so I dont want to spend too much time and money on tuning it the way it is.

[EagleMark]

WIthout mechanical issues it can be tuned in a day for $150.

4l80E requires a PCM swap along with some wiring. Engine mods, PCM can get to $10k easy...