Idles high after being in gear.

[BigRedOne]

Thats an old saying.

Wouldnt know what the point of 64,000 was for if it wasnt for Buick technical videos with a engineer with a thick southern accent. From the late 80s Lol



Also. your scan tool should not place a 10k resisted load across the ALDL because Im pretty sure thats what changes the ECMs behavior.

You must be registered for see images attach

This is from snap on manual for one of their tools, it could be a typo but I am pretty sure your stuff is going to be placing resisted loads across because that is used for setting and calibrating etc... whereas live data is frankly not used by many. if you had a lockup converter trans you can even use the ALDL to unlock/lock it on demand lol

You must be registered for see images attach

Some 1985-90 light trucks equipped with throttle body injection (TBI) engines (see list below) may experience a condition where fuel delivery to the engine is interrupted causing a no start. This condition may be caused by deterioration of the in-tank fuel pump coupler hose located between the sending unit assembly and the fuel pump. The deterioration is caused by prolonged high ambient temperatures in combination with low fuel volumes (or stale fuel) and extended vehicle storage.

Engine Displacement And RPO VIN Identification
2.5 L TBI (LN8) E 2.8 L TBI (LL 2) R 4.3 L TBI (LB4) Z 5.0 L TBI (LO3) H 5.7 L TBI (LO5) K

7.4 L TBI (Ll9) vin N

DIAGNOSTIC PROCEDURE: See fuel system pressure test. REPAIR PROCEDURE: Vehicles that are diagnosed as exhibiting this condition may be repaired by replacing the original coupler hose with a new Viton coupler hose kit, P/N 25028041. The kit consists of a new Viton hose and two clamps.

Thanx for the info. But the scan tools made available to me had no way of altering the if the 10k was in use or not. The only snap on scanner I had access to was missing the ALDL 12pin connector. So TunerPro Rt it is. I just need to learn how to use it. As far as fuel pressure goes. I have tested it and its where it should be 11psi. Thanx for your input.

 

[BigRedOne]

OK so here is some new info. first off I can't seem to get TunerPro to work with my bluetooth cable. Not going to spend an eternity trying. ALDLdroid works great as a scanner. But doesn't seem to get to in depth with info while running. I can see alot of info with key on as in what it's (ecu) supposed to be doing but only regular scanner stuff while running(no live timing or fuel tables). That being said. I went back to basics and reset my base idle one more time and decided to play with the idle with everything hooked up. If I lowered the idle to say 600rpm the IAC compensated and raised it back to 750. BUT when I raised the rpm the pintle would not go in to lower the rpm. reset the key and pintle fully extended and idle is back to 750. I'm raising and lowering it and resetting the key thru out this and realize that something is not telling the IAC to extend itself. It has full movement as resetting the key shows and the other thing is it never shows 0 counts when it is fully seated. The lowest I got was 20. So even doing the IAC reset several times. Unhooking the battery to reset the ecu. for some reason the ecu never sees 0 counts for the IAC even when it is fully seated. I even did the same tests with the old IAC and got the same results. Even set the pintle fully retracted by hand on both old and new and did resets and nothing but the same. I hate to sound like a broken record but several other sites keep telling me its the prom. That they had erratic idle issues or low idle that couldn't be solved or high idle when it was cold then would go away warm then surge when in park hot. All stated they tried everything we have done and a different prom fixed it. Not saying that this is the fix but I can't sit here anymore. I guess I throw more money at it and buy the jet prom and hope its it. Everyone here has been a wealth of knowledge and amazing help. But after chasing this for 4 months and unable to trust the truck will get me home if whatever the issue is decides to totally fail its time. I'm going to throw a prom at it and if that doesn't fix it (and I don't burn it to the ground). It's going to be getting either carbed or Holley stealth efi. I'm done with this unintelligent tbi crap. lol
So I pray that the PROM is the fix and I can get on with using this parking spot blocker once again.
I'll keep ya posted on how it works out.
Thanx again for everyone's wealth of knowledge and time.

 

[BigRedOne]

I mean, if you read what I posted Im pretty sure I specifically listed a TSB thing about PROMs...
whats your vin number? I can look at the GM calibrations for the most updated one. also emissions level? if you dont trust it I can give you the link but its not user friendly

Yes I read what you posted about the tsb mentioning replace PROM. But it is without context as to why or how to make sure that we aren't just parts swapping. No mention on how or why to test or diagnose. That is why (if you have read earlier in the post we touched on PROM issue) we were trying to make sure that is the issue before wasting money on it. I appreciate your input and source referral. I feel if I am going to do a prom it will be a aftermarket one that offers more than just a stock tune. I have ordered the JET 6 pack since this vehicle will be hauling another car half its time it can use the tow mode and the economy mode will hopefully help when unloaded. If you read thru the post we have tried EVERYTHING and I mean EVERYTHING possible to test parts and or replace parts and wiring. Done diagnosed and set and reset factory recommended settings and no change. This is my last and only thing left that hasn't been tried to save the TBI. If this doesn't work it's getting a carb or Holley's Stealth EFI unit. I don't have the time anymore to keep messing with it. It's been long enough.
Again thanx for your input

 

[PlayingWithTBI]

I mean, I dont think you tried this... whats your current prom and we can check the very easily accessed GM listing for the proper proms :/ they usually include notes as to what they are meant to fix / for

We already went through that on earlier posts, I found his BCC on Gearhear-EFI, and looked at it in TunerPro RT. It's for his configuration. We just don't know if his chip is still good.

 

[PlayingWithTBI]

I was talking about GM's website where you put in your VIN and then see what PROMs have been issued that could apply.

I would say good luck with an 88. FWIU they don't go back any further than ~92

 

[BigRedOne]

I was talking about GM's website where you put in your VIN and then see what PROMs have been issued that could apply.

TIS

So I guess I'm confused at what you are trying to discern. What info are you looking for that will help this issue? I put my vin in your GM link and it shows that I have the same PROM as it says I should. It list a couple other PROMS that were on other models with no info on them as whether or not they would work or improve my problem. So I'm confused at what you are trying to learn? This PROM I have now (if its bad) worked perfectly till now. I don't need a different calibration. I need to know if the one I have is bad, corrupted, broke or malfunctioning. If it is bad I am not going to replace it with another factory PROM. I will and have ordered one that will improve my Economy, power, towing and performance over the stock one. This issue was how do you diagnose the PROM I have? My conclusion is you can't so now a new one is on order. The whole purpose of this thread was help diagnosing and pin pointing the problem. We went thru several steps and this is the only step left. It is not diagnosable without just changing it and seeing if it works. If I'm missing something please say so. But please do so in a way that explains what you are getting at without just offering vague info that without context is more confusing than helpful. I am not a certified tech that is just going know what you mean when you say "put your vin in tis". I need to know why and what am I looking for when I do. And what I will achieve knowledge wise when I do.
Thanx for trying to help but now I just wait until the new chip comes and pray it fixes the issue.

 

[AuroraGirl]

So I guess I'm confused at what you are trying to discern. What info are you looking for that will help this issue? I put my vin in your GM link and it shows that I have the same PROM as it says I should. It list a couple other PROMS that were on other models with no info on them as whether or not they would work or improve my problem. So I'm confused at what you are trying to learn? This PROM I have now (if its bad) worked perfectly till now. I don't need a different calibration. I need to know if the one I have is bad, corrupted, broke or malfunctioning. If it is bad I am not going to replace it with another factory PROM. I will and have ordered one that will improve my Economy, power, towing and performance over the stock one. This issue was how do you diagnose the PROM I have? My conclusion is you can't so now a new one is on order. The whole purpose of this thread was help diagnosing and pin pointing the problem. We went thru several steps and this is the only step left. It is not diagnosable without just changing it and seeing if it works. If I'm missing something please say so. But please do so in a way that explains what you are getting at without just offering vague info that without context is more confusing than helpful. I am not a certified tech that is just going know what you mean when you say "put your vin in tis". I need to know why and what am I looking for when I do. And what I will achieve knowledge wise when I do.
Thanx for trying to help but now I just wait until the new chip comes and pray it fixes the issue.

I see.


I apologize for speaking and bothering you then.

 

[BigRedOne]

I see.


I apologize for speaking and bothering you then.

Hey no need to apologize and you weren't bothering me. I'm just confussed on what you were asking or showing me to do.

 

[BigRedOne]

We already went through that on earlier posts, I found his BCC on Gearhear-EFI, and looked at it in TunerPro RT. It's for his configuration. We just don't know if his chip is still good.

Hey Would you know for sure if there is a difference between a 5.7 fuel pressure and the 7.4? I thought they were all 9-13psi and mine is at 11psi. But I purchased a Haynes manual and it states the 7.4 is supposed to be between 26-32psi. This is the first I have heard of this and would like to confirm.

 

[PlayingWithTBI]

But I purchased a Haynes manual and it states the 7.4 is supposed to be between 26-32psi. This is the first I have heard of this and would like to confirm.

That's only for 94 - 95 7.4L which used smaller injectors with the higher pressure. You s/b good with 11 PSI