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Thread: AUJP 8D 7730 lean part throttle from gear change?

  1. #1
    Carb and Points!
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    AUJP 8D 7730 lean part throttle from gear change?

    I am working on an 86 El Camino with a 350. The block number is 10066036 and comes up as a Targetmaster replacement engine for 78 to 85 cars and trucks. I don't know how it compares to a 1990 F body engine. TPI with a 7730 ECM using AUJP bin. I worked on this car for a friend back in 2018. It was the first time I used an Autoprom. The car would barely idle and stalled when I started working on it. With a lot of reading and trial and error I got the car to run fairly well and got it to the point where it was reliable and drove quite well. During this stint I installed a BBK throttle body, Accel 24lb injectors, brand new injection harness from Howell Engineering, a heated O2 sensor on the drivers side and a wideband O2 on the passenger side. Both sensors just after the collectors. It has long tube headers. with an x-pipe. I also installed a 9 inch rear with 4.10 gears. It has a 700r4. The owner drove the car summers until 2023 when something happened and caused it to run differently. I told him to bring it over and I'll have a look.

    It turns out that a few shops in the area have taken a stab at working on it for him. The first thing I noticed was a remote mounted fuel pressure regulator, with the one on the rail removed and capped off. A new fuel pump has also been installed. Things were messy looking so I tested all the sensors, set the fuel pressure to 44 psi with vac line unhooked. It was set 15 psi too high. I noticed so many things wrong that I went through everything. I did a fuel pump flow test, injector and fuel rail cleaning, intake gaskets, new plugs and wires, 2 vac leaks repaired, set base timing to 6 degrees. Reset IAC. I also smoke tested the exhaust and intake system. With everything fixed up, I fired it up and took it for a ride. That quickly turned into installing a TCI adjustable TV cable and getting that all straightened out. Someone had also disconnected the 4 pin connector on the transmission and zip tied it back to the harness. I plugged it back in.

    Finally, after going on a 20 mile drive I could see that the car was running okay, but as I rolled onto the throttle in the 1800 to 2400 rpm range the car would hesitate badly and the wideband pegged to 16 (Ballenger motorsports maxes out at 16 on the display). Other than that, if i rolled onto the throttle pretty quickly, it would get beyond that rpm and go back to normal. A fast stab or getting into wide open throttle didn't have any problems. After looking through the tune I did years earlier, I decided to start a new tune from a stock AUJP bin. I started off by turning off all the emissions and entering the injector data that Accel provides. I ran the car and it hesitated and went lean just the same. I turned off PE and did a log and worked on correcting VE. After correcting VE the hesitation is still there. I ended up adjusting too many settings in PE and AE as well as other things in the next few drives that I couldn't keep track of what things were helping or hurting.

    The whole time working on it I couldn't help but wonder what may be causing this change in drivability since I had last worked on it. I have found out the 4.10 gears were changed out to 3.55 gears or possibly 3.27 and I am wondering if this may be the thing that has been changed on the car specifically relating to MAP change in these driving conditions. I am thinking that accelerating with a taller gearset may have created a situation where there is more load on the engine in the 2000 rpm range where this hesitation and stumbling occurs. Maybe the AE-MAP table needs work now? Has anyone else run into a similar situation?

    Some other questions I also have. A couple of times the SES light has flashed 2 times and the car dies for a split second then carries on fine. When I play back the ERRORS list view I can see that moment where every single error on the list flashes for that split second. I don't see any code stored. Does anyone know what would cause this?

    When uploading a new bin, is it best to clear memory first by disconnecting the battery?

    Is it okay to log BLM as soon as the engine is up to temp when you upload a new bin? Or should some miles be driven first?

    Some of the dashboards and monitors in Tunerpro have "in MAP AE" "in TPS AE" and "in PE" - I've never seen them active but would like to get them working if anyone can help.

    I am using the newest TunerproRT release 2025, AUJP bin, S_AUJP v5 xdf and S-AUJP v5 wb adx logging a Ballenger Motorsports wideband through channel 1 of the Autoprom with a G1 adapter.

    Any suggestions or help is greatly appreciated.

  2. #2
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    Re: AUJP 8D 7730 lean part throttle from gear change?

    Welcome to the forum.

    You're putting a bunch of work into getting this car running well again. Hopefully we can help.

    As far as clearing the memory, I would not worry about whether or not it was cleared before or after the new calibration was uploaded. I would be more concerned with ensuring I had a routine so I did not forget to clear memory.

    It is perfectly fine to start logging BLM immediately after starting the vehicle. Watch your closed loop flag to ensure you are in closed loop before expecting to see BLM or INT changes. Remember that INT changes before BLM.

    Yes, changing gears can definitely require more tuning in the tables. Fast throttle change generally creates more acceleration enrichment. Slower change tends to highlight issues in the volumetric efficiency tables. If you manually select a lower transmission gear and drive through the same conditions, does the car experience the same problem? If no, then the hesitation may be more noticeable due to the rear gear change.

    I am surprised the AE flags are not indicating AE is active. I would expect the car to be challenging to drive without AE working. I might take some time to figure out how to get accurate data from the AE flags.

    The flashing check engine light is troubling. I might be looking for a loose connection or an ecm problem as the source of the hesitation. I might also be looking at the fuel tank... was it changed when the pump was replaced? Does it have proper baffling for an EFI equipped vehicle?

    Good luck...

  3. #3
    Carb and Points!
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    Re: AUJP 8D 7730 lean part throttle from gear change?

    Thanks for the information 1project2many.

    I am looking into getting the AE and PE flags working for my next test run. I have two ECM's and two memcal's. One memcal is from a v6 with a cylinder select jumper, and the other is the correct AUJP. I have had the 2 flash SES light problem driving with either ECM or memcal installed. Although I have inspected the wiring, checked grounds, and have had every connector off, I will keep looking as I work on the car.





    If you manually select a lower transmission gear and drive through the same conditions, does the car experience the same problem?
    - I have not experienced the hesitation while holding the car in 1st gear. But It does happen in 2nd 3rd and 4th gears when I am cruising near 2000 rpm and start to accelerate. When I view a log I can see the narrowband plummet to 62mv, the wideband shows maxed out, INT climbs way up and sometimes goes to max. I can back out of it and get it to stabilize and pass through this rpm range. I do similar things with the throttle at higher rpm so I can watch in the monitors to compare the events at different rpm's.

    I might also be looking at the fuel tank... was it changed when the pump was replaced? Does it have proper baffling for an EFI equipped vehicle?
    - I am glad you mentioned this. When I checked the fuel system, I did notice the tank is new. The sending unit is a 2 line. I believe it to be the carbureted sending unit with the original vent line being used as the return line. Someone welded a nipple on top of the tank for a vent line. I doubt this tank has baffles. I have only been running the car with a full tank and filling up at no less than 1/2 tank. Without having baffles, could it cavitate this consistently with a full tank? I have smashed full throttle from a stop and ran through 3rd gear with 12.5 to 13 AFR a few times with no hesitation or stumbles. This was with the best VE table I had made so far, and haven't really considered the fuel system to be the problem. This would be very interesting if it is.

  4. #4
    Fuel Injected! ULTM8Z's Avatar
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    Re: AUJP 8D 7730 lean part throttle from gear change?

    Any idea what cam is in the car?

    Possible to get a datalog and see the bin? My laptop died the other day and a replacement is on the way, but I'd be happy take a look and see what's going on after I get my new one up and running.

    I've spent A LOT of time learning about AE on the 7730 getting my Miniram intake dialed in. So I may be able to help.

    It's good you're in S_AUJP, because it has a lot of obscure AE parameters that are not visible in the standard 8D xdf's.

    From what you're describing, it seems like you may have a AE delta MAP issue.

    In the meantime, you might want to upgrade to S_AUJP v7. I'm on v7 and the AE scalars seem to be more well defined than in v5.
    __________________
    1971 Pro-Touring Camaro
    GM HT383 shortblock, MiniRam manifold, AFR heads,"8-speed" transmission (700R4 + Gear Vendors OD)
    Self-Tuned 7730 ECM
    PM me about tuning your 7730 ECM

  5. #5
    Carb and Points!
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    Re: AUJP 8D 7730 lean part throttle from gear change?

    ULTM8Z I have read a lot of your information on AE tuning. It is a lot to grasp and I am more than willing to to upload a datalog and bin. After researching possible problems when using a 6 cylinder memcal, I have recently gotten an AUJP memcal because it turns out the knock board on the memcal is different. After viewing the datalog of a short ride I did notice knock retard was now pulling up to 5 degrees of timing, where the v6 memcal never pulled more than a degree and and what looked like random small spikes on the monitor. I don't know if this was affecting my tune or not. Oddly enough the memcal has a sticker on it that says PS-CAD5 350-TPI-7730 but on the side it says ARYC which is for a 2.8 v6.

    I decided to start from a fresh AUJP bin and do VE corrections with the AUJP memcal. I think I can get to having a decent VE table much faster now, and weather is the only thing stopping me from taking the car back out. It been snowing every few days. If the roads clear out and dry up, I will take the car out.

    I will download the S_AUJP v7 and use that to take the next ride and log BLMs. I hope I can get the AE and PE flags working as well. I'm not sure if they are supposed to work with the S_AUJP bin, or if I need to change something to get them working with the stock AUJP bin.

    Here are the camshaft specs

    Hydraulic Flat tappet Camshaft- #14088839
    Intake Lift-.383" Exhaust Lift-.401"
    Intake Duration @ .050"- 194 Exhaust Duration @.050"- 202
    Lobe Seperation-112

    I'll work on getting a datalog and bin uploaded. Thank you!

  6. #6
    Fuel Injected! ULTM8Z's Avatar
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    Re: AUJP 8D 7730 lean part throttle from gear change?

    That cam is pretty much the same as a stock TPI.

    In reality, the factory AUJP bin should work just fine I would think.

    I'm wondering if something else may be wrong with the setup.

    Any rate, I'll wait to see the datalog and bin... laptop should be here around next Tuesday. Not sure how fast I'll be able to re-establish all the software on it... so no rush on your part. I may not be fully up and running until the following weekend.
    __________________
    1971 Pro-Touring Camaro
    GM HT383 shortblock, MiniRam manifold, AFR heads,"8-speed" transmission (700R4 + Gear Vendors OD)
    Self-Tuned 7730 ECM
    PM me about tuning your 7730 ECM

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