Stalling at Idle+ Hesitation off Idle at around

[JoeMechanic]

1200-1600 RPM's.

Replaced,Fuel Pump,Filter,Plugs,Wires,Intake Gaskets,Cleaned out Intake and Air Valve(Throttle Body).Runs great otherwise when I punch it and get it on Highway doing 60 mph.This is a 3.1L 1995 Grand Am GT the engine is bone yard 3.1 out of a 1996 buick skylark.I did find an update on alldata online...does anyone know how to update the ecm without having to go to the dealership to get it done?.

[IsaacHayes]

Sounds like a fuel issue to me. What are the FPR pressures at idle, and at idle with no vacuum line on it?

[JayZ26]

...Sounds like a miss then. Are you getting a code?

[IsaacHayes]

FWIW my bog taking off from a stop if I layed into the gas hard was a bad O2 sensor.

But anyway, what brand plugs did you use? Please don't say bocsh platinums.

BTW what update was alldata talking about? Details?

[JoeMechanic]

Problem Solved...

Issac Hayes is right again..I replaced the 02 sensor with a quality Denso and no more problems..its runs excellently now and my engine job is almost complete.The SES light came on though after a 30 mile highway test drive so now I have to find me an ALDL cable,laptop and download the tunerpro software.Isaac have you used the tunerpro software yet?..if so can I clear the SES light with it like I can with my OBD2 scanner.I am glad actually that the SES light is on..this tells me I have one or two more problems elsewhere but man the car runs fantastic now!.After cleaning the injectors from the original engine(scraped rust off and painted them too)Installed new orings,new fuel pump and filter car purrs like a kitten and has a nice exhaust tone out the back from dual mufflers.

[JoeMechanic]

Alldata Update:File in section 6E-Engine and Fuel

Emission.Bulletin #51-65-11 March 1995 Subject PCM used SFI-66
Bulletin #57-65-24 November 1995 Subject cold starts stalls and or a tip in hesitation on acceleration models:1994-95 skylark,regal...1994-95 beretta.corsica,lumina.monte carlo...1994-95 achieva,cutlass supreme...1994-95 grand am,grand prix with 3100 v6 engine( Vin M-RPO-L82)

condition: some owners may experience a cold engine start stall and or a light acceleration tip in hesitation on a cold engine.

correction: A new flash prom calibration has been released to service vehicles which experience the conditions metioned above.The new calibrations add fuel to the Throttle position sensor enrichment algorithm below coolant temperatures of 80 degrees celcius(176 degrees farenheit)

Part #Model Year 94 carline L axle ratio 2.93 emission export calibration number#16230724

complete listing of new calibration numbers will be available for Tech Line Tools starting with the October CD releases from GM Service Technology Group (STG)

Important: Do not attempt to order the calibration numbers from GMSPO.The calibrations are programmed into the vehicle's powertrain control module via a Techline Tool device. Labor operation J6355-Prom description Reprogramming

Prom-Reprogram Using Off Board Program Adapter
File in Section 6E Engine and Fuel Emission
Bulletin# 73-65-13
March 1997
Subject Reprogramming Capability using the Off board Programming adapter models 1993-1997 passenger cars and trucks GM(applicable reprogrammable vehicles)The General Motors vehicles contain ElectronicallyReprogrammable devices(i.e. PCM,VCM,ECM).These vehicles cannot be programmed through PROM replacement,however service programming capability is available through the TECH1/1A,Tech2 and techline terminals via direct or remote programming.

The EPA has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner.

Although programming of controllers has become a common service practice at GM dealers/retailers,the EPA has recieved reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device(ERD)over-the counter.As a result,on August 1,1995,the Federal Governmet issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1,1997.

[JoeMechanic]

OBPA for Tech2 Programming can be purchased from Kent Moore company 1-800-345-2233 (Part# J41207 REV C) Free of charge to GM delerships/retailers.Support on how to use through GM techline(TCSC) at 1-800-828-6860

https://www.spxKentmoore.com

[JoeMechanic]

By the way the Plugs are AC DELCO's baby!.

[IsaacHayes]

I have all the definition files you could want to scan sensors, codes, and clear them for the 94-95 3100. I use both tunerpro rt and scanner pro.

PM me if I haven't replied by tomorrow in this thread with links to them. I have made very complete ones.

Sounds like you're on the right track! Does the SES stay on or go off after you restart the car? Could be clogged EGR or EGR port in the plenum. Cleaning those out can fix that.

[JoeMechanic]

Thats my next step..I need to borrow my sisters laptop(I don't own one but currently shopping for a good used one).I downloaded tunerpro on my desktop here just to see what it looks like but can't see too much until communication with car's ECM.The SES light comes on after about 30 minutes of highway driving..if I turn the engine off to go into a store and come back out and start it its off.I know it has stored a code so right now I am in the process of getting my diagnostic equipment(laptop with downloaded software installed)purchase an ALDL cable and go from there.Do you know where I can get a cable for under $30?.As far as the EGR goes you have to remember that I installed this motor recently(bone yard 1996 skylark)I pulled the intake and replaced intake gaskets prior to installing.Cleaned out the entire intake when it was off of all carbon buildup..the ports are super clean and I cleaned the carbon off the EGR valve..so I don't think this is a problem.The biggest problem was a bad 02 sensor which I should have replaced along time ago since it was the bone yard engine one that I left in the engine(dumb move on my part).The new sensor made this engine run like new no more hesitation,stalling and what have you, it runs super!.I will let you know about the links you mention..probably in 2 weeks from today maybe less I will be ready..I just need to order the ALDL cable..thanks again for all your help..I'm calling you the forum genius from now on..lol.

[JoeMechanic]

One more question....if its the EGR valve(if I get a code for that)would it hurt any to dremel the EGR port on the intake bigger?..you know remove some aluminum and make the port bigger?.It is very clean so I will be surprised that its that..maybe the code has set prior to replacing the 02 sensor..I never cleared it by disconnecting battery power..I want to scan it first before I clear codes,Joe.

[IsaacHayes]

Check ebay, sometimes you can find them cheap on there used. To make the port bigger it won't hurt anything unless you break through and cause a vacuum leak lol but it will be hard to go all they way through to the other end. If the light is coming on and going off then it's an active code. Sounds like EGR though from what you describe when it comes on.

The EGR port, did you put a wire all the way through the passage to verify it's open? Try the other EGR as well, maybe one has a dead coil in the solenoid.

I will try to get the files posted in this thread for you tonight.

[IsaacHayes]

That PCM re-flash is interesting. I know what they are talking about. My car does it if you hit the throttle a certain way when it's cold it will hesitate. I know there isn't anything wrong with my car but it never dawned on me that it could be tuned out. hehe

Can't access my site, but I did upload the files. I'll wait for Brad to get back to me on that.

I just made it into 2 files for tunerpro rt. one scans data sensor values, then you load the other and connect and it's set for reading codes. You can send a clear codes command after the "disable comms" command to clear the codes from either definition file.

[bszopi]

Can't access my site, but I did upload the files. I'll wait for Brad to get back to me on that.

Fixed.

[JoeMechanic]

Ah hell..to get setup with laptop,cable,software +

definition files I am close to $300.Laptop are about $200 used cable about $50 and if software costs anything.I just saw some decent prices on Autoxray scanners that come with cables for obd1 and 2(does both)on ebay for about $50 bidding.I can alway's purchase a laptop later plus I will have the cables..hell the cables are worth more than the price of this scanner alone..lol.