i have a 90 camaro 305 TBI. it really struggles to start at any temp, but will be noticably worse to start at 120-130 degrees. i have to pump the accelerator and i can hear the throttle body opening as i do this, but the motor just doesnt want to catch. once it does, it idles fine but it hesitates badly coming off of a stop and is very sluggish under 2000 rpm-sometimes i have to floor it from 1500 just to get it to get up to 2000. above 2000 its great.

i pulled a code for the dying off the computer and got the normal code 12 communication code, and then 43 which is low ESC voltage. so i took it in for further diagnosis, but the morning i took it in i let it die to make sure the code would be in the ecm. i took it in and they got NO CODES. the only thing they said was i needed an IAC cause it idled high (1000 rpm) even though i never get it to idle over 500. i put that in and it made no difference. why would my ecm clear itself? if it was toast, wouldnt i get a code for ecm failure? what do you think is the deal? it also runs real lean. ive had this problem for a year and NOBODY knows what it is. i also have tried a new MAP but that didnt help so I really would appreciate your help on this subject. thank you

 

Well I could tell you the problem....but I'm not GM Tech. Sorry.

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
JSP Motorsports
ICON Motorsports

 

come on, please??? if you know, tell me. its eaten at me for over a year

 

Well I've got a good idea too, but I'm not GMtech either.

 

oh for christs sake help me anyone

 

Lesson learned? There is a lot of knowledge here, don't address one person only.

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86 Camaro Sport
383 Speed-O-Motive Crate Engine, Raptor 700R4 Tranmission, Trick Flow Twisted Wedge G2's, 58mm Accel TB, 3.73 Auburn Pro, SLP Cold Air Induction and Headers, Dynomax Cat-back, Serpentine Belt Setup, Dual IROC Fans, Jamex springs, 16" IROC Rims, 36mm/24mm Sway Bars, Global West Steering Brace. Hotchkis Rear LCA's,Panhard Bar and SFC's.
My Camaro Project

 

i know what i'd be looking at if it were my car. i know you don't want to hear from me either since i'm not Mr. GM Tech.

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ICON Motorsports

1st & 3rd
MM Black Diamond 538 F&AM

 

Ouch, you all are harsh...


Anyway, I'm leary about the ECM being bad. There is a code for "bad computer", but usually when something like an injector driver goes bad, the computer doesn't know.

I don't know what to tell you about the code, other than that it will clear after I think 40 consectutive starts w/o seeing the failure.

The hard starting could be an IAC problem, but it sounds like whoever was looking at your car is just guessing. I would reccomend you have somebody w/ a tester actually check it out.


As for the running bad problem, there is a long list of things to try. Some things that I see on the TBI engines that stick out in my mind would be fuel pressure, vacuum leaks, and injectors.

These engines need to see between 11-15 psi of pressure. Anything below that is trouble. It is a little difficult to check fuel pressure on these since there is not schrader valve, so you will have to find somebody w/ a TBI pressure gauge, or the adapter to hook up a regular fuel pressure gauge. This would be the first thing I would do.

These engines are also known for problems w/ the TBI mounting gasket. Spray some choke cleaner around the base and see if you can't detect any vacuum leaks. These leaks can really throw the computer off.

Also check the injectors. Make sure both are firing. I see alot of problems w/ the hard wires that go up through the throttle body and to the injectors. They aren't as soft and flexible as regular wire, and tend to become brittle and break inside the insulation. I have also seen problems w/ the injectors themselves. When they fail, they usually just start dumping fuel, and the engine runs pig rich, but the last 305 TBI I worked on, it ran about like yours, and I ended up putting two new injectors on.

Make sure too, that the grounds on the thermostat housing are clean and tight. Take them off, and sand them a little and wire brush the stud to ensure a clean connection. These are the ECM grounds, and will cause problems if not right.

Good luck.

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If you live in Southeastern US, check us out!
South East Thirdgen

GM Master Tech
ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
Whatever chip I feel like burning,
JET AFPR, Ported Plenum,
TB Coolant Bypass, Custom Cold Air,
SSM SFC, KYB Shocks, Boxed LCAs, Wonder Bar,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
-->14.97 @ 94.9 MPH<--

'97 Bonneville SSE

 

Thank YOU, GMtech, for helping me.

*Disclaimer*
The only reason I posted specifically asking GMTech for help is because he is a master technician who im sure has seen many of these cars. In no way am I saying nobody else knows anything, I know you do, I just asked him because of his credentials.

 

your lucky he even replied to your post, just make sure in the future to be nonspecific.

 

302GT, beleive it or not, the other members are actually just trying to help you by conveying a point. You asked for me specifily, and this topic as as old as "carb or TPI?" but the point is I can't make it here everyday, and if you only want me to answer, you may not get anything, because sometimes I go days w/o showing up here, and it only hurts you. I may have alot of credentials, but alot of members here are just as good, and actually excell in certain areas over me.

Frankly, I'm flattered that you asked just for me, but you will get better results if you ask the crowd in general. "two heads are better than one".

------------------
If you live in Southeastern US, check us out!
South East Thirdgen

GM Master Tech
ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
Whatever chip I feel like burning,
JET AFPR, Ported Plenum,
TB Coolant Bypass, Custom Cold Air,
SSM SFC, KYB Shocks, Boxed LCAs, Wonder Bar,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
-->14.97 @ 94.9 MPH<--

'97 Bonneville SSE

 

look now i know how this crap works-i had about 300 posts and i ****ed up and had to re register so i know what to do. i never said nobody knew any better, i just wanted help from someone who just may know for sure what this is-this car has been in and out of shops AND dealers for OVER A YEAR now for JUST THIS PROBLEM, and NOBODY can figure it out so if it means a few more days of having a ****ty running car and a few more hundred dollar parts, so be it. i have been here and on camaroz28.com everyday and nobody bitched when i asked specifically for info on white face gauges from a guy, instead everyone who had something to add kindly said it, unlike the many arrogant people here. gee i think there was another post for GMTech and nobody bitched at that guy, so whats the deal here? i appreciate the wealth of knowledge here and share what i know but i dont need to log on to see 8 posts and go ok heres some help just to see a bunch of smart *** remarks. but nevermind, maybe ill let this thirdgen rot to hell like 80% of them out there and just add to the crappy rep these cars get since nobody was really kind enough to help, just to take the time to be a smart *** .

 

302.... You took it as people being a smartass toward you but actually they were just kidding around, man. Don't take it personally! We all need a laugh now and then, and if it happens to be at the expense of you or I or anyone else, well, life goes on. 99% of the people here are more than willing to help you out but not if you have this "scorched earth" policy you've just ranted about. Take what these guys said and use it to your advantage, or to someone else's advantage.... most of what I help people with here are things that I've learned from hanging out here for the past 3 years, you should know that.... apparently you've been here a while before. Good luck to you.

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Kevin Irving
85 Trans Am WS-6, 305 TPI, custom burned '86 PROM with '87 "165"ECM, Accel Supercoil & 8.8 Wires, Rapidfire #2 @ .055", MSD 6AL, 1.6:1 Roller tipped rockers, Homemade AFPR, K&N cone, no airbox, Aluminum Driveshaft, Wonderbar, TB Coolant Bypass, Ported Plenum, Descreened MAF, Syclone Fuel Pump, JET Airfoil, Mobil 1 synth in all but transmission.

15.556 @ 86.65mph, Nov 10, 2000.... I know it sucks.. but it will get better!

http://www.geocities.com/transam85tpi/

Member - The Tidewater Trans Am Club, Norfolk VA http://www.geocities.com/ttacva/

 

Listen, what you write is what you mean. There's no room for 'I was just joking' or 'He was just joking'. WTF, how are you supposed to show emotions with letters.
We need Judge Dread on this board,
"I was just joking"
"I knew You'd say that
Guilty-The sentence is death."

 

Thank you, Steve.

I have posted this topic three or four times before and got no replies except the ones from myself that were 'ttt' and 'anyone? please?' so that is another reason i asked for a specific person. I understand many of you may know but nobody replied at all before.

 

I think you are refering to RobP's post about his ZZ4TPI RS Convertible. One of the reasons he directed it towards me, is because he has been coming to my house so I could help him, and I think alot of people didn't bitch is because alot of people knew I was personally involed, plus he also included "and all, please help" in the title, so it wasn't just for me.

I think its stupid to waste your time, my time, and everybody elses time arguing over who should help who around here. 99% of my posts are helping so if I'm not helping, I'm not doing anything, so I don't care who somebody asks for, I usually pitch in my $.02. Other people don't feel that way, so you just have to handle it as you see fit.



------------------
If you live in Southeastern US, check us out!
South East Thirdgen

GM Master Tech
ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
Whatever chip I feel like burning,
JET AFPR, Ported Plenum,
TB Coolant Bypass, Custom Cold Air,
SSM SFC, KYB Shocks, Boxed LCAs, Wonder Bar,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
3.73 Posi
4wheel Disc Brakes

'97 Bonneville SSE

 

now that we've beat this dead horse i think it's time to put it away for good. i can't speak for anyone but myself, but mostly i was just having some silly fun. if anyone doesn't like it there isn't much to be done at this point. as a rule i don't reply to threads asking for someone by name. there is too much knowledge here to limit yourself to one person, if you want one persons thoughts use e mail. i believe it would serve anyone better if they got the same advice from several others. not that Mr. GM Tech doesn't know a thing or two, but what about engineboy or camaro mike to name a couple that are also ASE certified mechanics. how many others here are ASE certifed? how many have spun wrenches for a living or for fun for the last 25 years? if any one has a problem with the members, moderators, or adminstrators here write them, and the adminastrators and see if your problems can be resolved. thank you all for your time and attention.

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ICON Motorsports

1st & 3rd
MM Black Diamond 538 F&AM