I test drove the car at lunch time at it was fine, now it will crank and not start. ???? Getting frustrated. I have nothing here to test for spark. I know its getting fuel. I tried disconnectting the MAF sensor and that worked once. It started then i shut it off. reconnected it, nothing. I am hearing alot of clicking noises coming from the front of the motor passenger side when I crank the motor. any ideas??

Wow, that sux. These new injectors seem to click louder than the stock ones. I can hear them when the engine is idling, but I don't notice them when cranking. No check engine light when it runs?

I had a CTS (coolant temp) fail a couple of weeks ago while I was working on this problem. It had the symptom something like you describe, but the car would start with allot of pedal pumping. It would hardly run (since the ECM was pouring fuel in), but after 3 seconds the ECM figures out that it really can't be -40C outside so it turns on the check engine light. It then goes into a mode where you can sort of drive it, but it's pretty hateful.

Lots of good info in here. My car has pretty much the same symptoms as everyone else. Looks like I will be looking at the injectors first.

When i disconnected the MAF sensor the first time it started, then the SES light came on. it ran rough so i shut it off. The clicking noises actually sound more like arcing like i have a bad ground somewhere. Why me?!?

You sure a plug wire didn't ground out on the exhaust manifold? This would cause a rough idle and a ticking sound.

I checked the wires, they are fine, I always check routing to make sure they are away from metal. It did start after sittin all nite. but I just tried to drive it this evening and now it won;t start again. So know I have a no start when warm/hot condition. Whats goin on here?? It never did this before the injector swap.

After a quick spark check, we determined it wasn't getting spark. I swapped in a spare coil and it started. What are the odds that the coil goes bad right after I swap injectors?? Anyone else have luck like mine???

Well how does it run? I had a CTS fail when I stopped at a convenience store. Fine when I shut the engine off, -40C report when I started it again.

It runs great now, just got back from it first real test drive. When u say -40C report when u started it again, do u mean u had a scan tool hooked up? So did it run with a bad CTS?

I didn't have the tool with me, but that was what it was indicating to the ECM. It didn't want to start, just turn over fast like it was trying. I had to really pump the pedal to get it going. When it took off, it poured black smoke and would only run with it revving. After 3 seconds, the check engine light comes on and it ran well enough to get it home, but it ran poorly. New sensor and it was back to normal.

I have been watching this thread as my 89 Iroc developed the same problems. Rough idle,wants to die at stoplights when warm,runs good cold, hard start,etc... I went through the entire ignition system, did the egr valve,o2 sensor. MAF sensor replaced about a year ago and when I unplug it the car runs rougher, so I don't think it is bad.
I replaced IAC valve and TPS and set it. Still runs the same. I had a code 45-rich exhaust shortly after the problems started. It will not set just driving around town, but when I go to work and get on the interstate it comes on about the time the car warms up. I finally took it to the shop and they put in an ignition module (I had already had mine checked and my spare). Guess what? That did not fix it. They said it showed low output or something. They adjusted the timing (retarded) and it quit hunting and started better for a day ot two, but then it started running hot. I did not feel comfortable shutting it off to fill it it up with gas for the last couple of weeks, so I have just been filling it up while running. Before they adjusted the timing it was not running hot. when it did I found that the heavy duty fan switch had falen off and I fixed that and it still runs a little hot. One night when it was running hot I stopped to get gas and the air coming out of the gas tank was so hot I was afraid to pump the gas in, so I left the gas station. I guess the fuel in the lines running over the hot engine picks up the heat. Anyway I think they just hid the problem and created another. I know retarded timing can cause overheating. My question is do I need injectors or has the engine jumped timing? half my injectors ohm below 12 ohms. The car has about 150k miles. It is stock. I also noticed my cat is missing. It once passed emissions when I lived in the city.
Thanks

Sounds like you've eliminated pretty much everything but the injectors. A wide variation on your injector resistance (ohms) is never a good thing. Don't worry too much about the warm fumes, they'll never get hot enough to ignite, plus adding new fuel will just help to cool it all down. The fuel gets heated from being circulated thru the hot engine compartment and back to the tank. Having an oversized fuel pump adds to this issue. If you can do the work yourself, the $200 spent on reman injectors and a gasket set will at least rule them out. They certainly solved my problems.

Hey there guys, I've been reading all these threads and I think I might have the same problem... I got a 87 GTA, I did some maintance last fall,(sprak plugs, wires, cap, rotor- ac delco, MSD Blaster Coil). It idels fine at stoplights. So I'll be stopped at a light, then when i give it a little gas on green it starts Chuging/ Surging forward for a few seconds/ 10-30 feet, then it justs takes off, even sometimes when coasting at 50 km/h's and I stomp on it there's a little hesitating/ misfire feeling to it. But nothing as bad as when it's at a stoplight. It feels like a misfire and it feels like the engine floods a little. Even last night while Chuging/ Surging it gave a Backfire Sound... Does any of this sound familiar to you guys.......HELPThankx Paul.

My misfire is gone.....I've had the same AC Delco battery in my car for about 4 years now and i knew it needed to be replaced. Since i was already misfiring, and spending time under hood, i went and replaced it with a new battery. Then took my gearhead buddy for a drive to help me figure out what was causing my misfire...... 2 test drives since the change and my GTA feels great again.... just a bad old battery.....huh....

Well, looks like I found a thread that may hopefully solve my problem. Search button only does so much.

Alot of people give up on their 3rd gen and end up selling/trading their car. I don't want to do such a thing, as I want to keep the car. I guess I'm still holding out for hope, even if it's a glimmer.

I have nearly identical problems as pretty much most of the people that posted on this thread (car is sluggish, wants to die at a stop sign, etc...) Heck, alot of everything on here described what I tried to have answered back in the Q&A portion of "my car won't start etc" thread.

I've had alot of stuff replaced, including injectors (I have 21 LB venom injectors which replaced the stock 19 LB injectors the owner didn't bother to change *sigh*).

I'm still having this problem, and I'm starting to wonder if it's the injectors (they're still pretty much new). Did I buy the wrong ones?? Or perhaps I got a bad batch? I'm in a state of denial on that, as I don't wanna believe that I wasted money on injectors, only to find out they were the wrong ones. The fact of the matter is, I'm sure we all wasted money on a part trying to diagnos a problem in hopes of a "cure." I'm without a doubt on the same ship.

However, I'm in a small dilema.

When I bought the car, it originally had the 305 TPI setup. The 305 got tossed out and a new 350 was put in and laced back up with the TPI setup. Mind you, I wasn't the one who did that, as that's how I bought it off the owner. I'm green when it comes to domestic (especially older cars), but I know my way around decently on import. I don't want to regret buying this car, despite it having it's own "personality."

Here's my dilema, and I was wondering if it could relate, or have anything to do with this kind of problem. When the person who done the switching of the engines, he left the STOCK 305 ECM and chip inside. So pretty much right now, I have a car that has a 350 engine that's running off of a stock 305 ECM and stock chip. I recently purchased a remanufactured ECM made for the 350 setup, but now I'm looking for the chip that goes with it. Should I focus on the chip, or should I focus on injectors (I don't see how they could be bad, as they are practically new??) I could be wrong, but that's what these kinds of boards are here for. To help fellow 3rd gen owners out.

Could this have anything to do with the associated problems that everyone seems to be experiencing these days? I'm at a loss, as I don't know what else to think of.

Sorry for the long post. Any help is greatly appreciated! I rather have a 3rd gen on the road istead of one being in the grave.

You need to hook up a scan tool, or have someone hook one up for you, otherwise your just shooting arrows in the dark. You need to check BLM's in conjunction with the integrator, your O2 readings, your TPS, IAC, etc. Surging normally occurs when you have a vacuum leak (O2 correction), either that or when your fast idle screw has been altered, and the commanded RPM is fighting itself back and forth....

Your #1 priority should be to get a 350 tune in that ecm, it will never run right with the 305chip no matter what else you do to it. incidentally you didnt need to change the ecu the 305 and 350 are the same it is just the chip thats different.

Not necessarily. He's running an engine with adequate sized injectors, and although the stock tune found in the 305's prom isn't necessarily ideal for a 350, BLM can still be able to compensate for correction, unless his camshaft isn't stock, then I can see a problem. I've ran 305 prom's w/350's, and vice versa, and there was never really a problem, so long as you give the engine what it wants. The only proms that would cause a surge, even if the injectors were matched to the cubic inch displacement, would be running a manual prom with an automatic, because the ECM only commands 600-RPM, even without a load, thus you get surge no matter what you do. But in this case, the ECM doesn't know how big the engine is, all it knows is what it reads, lean or rich, and that is where O2 correction comes into play. If he was running 19 pound injectors, then I could see a lean condition, but either way, everything will immediately become prevalent with a scanner....

I completely agree the car should be scanned/datalogged, of course it needs to be done by someone who is familiar with tpi's and knows what to look for, and that can sometimes be difficult for some people to find. The issue i see with the prom being incorrect is, The car is running 350 sized injectors but the ecu thinks they are 19's and so it is going to be excessively rich, which the ecu is going to try and compensate for and it may or may not be able to do then you can get a rolling idle. A MAF car will compensate some for changes which effect the VE of the engine but if the injector constant is off, i think it will cause the sorts of problems being described.

Street Lethal: Awhile back I took it to my mechanic (he owns a shop), and he hooked up his scanning computer (awesome diagnostic computer), and well... When he went to unplug it from the cigarette lighter, the pronged ends snapped inside the cigarette lighter. That was when we were trying to figure out this ordeal on what's happening with the car.

Out of curiousity, what is BLM's?

I had my hoses checked and had them replaced already. Also, I forgot to mention this, but when I put the car in reverse, sometimes the car will die as well.

Also, the fast idle was altered with, but only slightly (the car used to idle at 900-1000, and that was after being warmed up.) It got lowered down to around 600-700 so it's not as bad (but occasionally it does go toward the 1000 mark then will go back down to 700). I'll post more info on that subject on the notes I made yesterday morning in a different post.
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MaxpowerTA: I don't know of any places that tune ECMs for thecamaro. Alot of the places I've seen done tunes for newer model vehicles. I'm thinking of just buying a new chip since I'm already good to go on the ECM.
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Street Lethal: I'm thinking of getting a 350 chip just to be on the safe side. I read a post in regards to one of my other posts about having a 305 prom in conjunction with the 350, and was informed that the engine will act a little spuradic, as it's pumping 305 information to a 350 and the 350 is sending different information the 305 chip wasn't equipped with. Also, the camshaft I believe is still stock. I'll dig up more specs on my car later, as I gotta look for it.
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MaxpowerTA: I want to get it checked out, but it's very difficult to find someone who is pretty keen with TPI's and know's what to look for. It makes me pretty sad, but I'm still searching. I was thinking of getting a Tuned Port book. Would that be benneficial?

From the looks of it, I seem to be pretty good on Injectors, correct?? Also, I DO agree with the both of you about getting it scanned/data logged, but for the first part, I want to clear it up on getting the 350 chip for it (it makes sense to match things that go together rather than mismatch). I have a feeling it won't clear the issue up, but it should do something (at least get the potential I have out of the 350)
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I'll post up specs of the car on a different post and what's been changed. I'm also going to post some notes that I've taken yesterday morning to give anyone reading this a better idea.

Morning startup at 5AM

1. Started the car up. The Volts on the battery gauage in the car read at 13. No rich smell detected. Oil pressure gauage reads 50, very close to 60. Idles at 700 on startup, then dips down to the 500/600 range.

- I downpress on the pedal slightly to even out the RPM's to 700 for a few moments. Oil pressure seems more steady/consistant, with a reading of 50. The car dies....


2. I start up the car again and it's idling at 700 RPM's with 50-53 reading on the oil pressure gauage.

- I turned on the manual fans at 180* to keep the engine cool. Oil pressure is at 49 PSi. Idle dips down to 500, 600, and back up to 700, and stays at that reading for a bit (it somewhat bounces between the 5/600-700 RPM mark at times). The car dies again....


3. I turned the car completely off and step out. I smell a little richness coming from exhaust.

NOTE: I heard a "clicking" noises coming from the engine bay. Are those perhaps the injectors making that noise? Just curious.

End of mini report.

Hmmmm.....maybe you guys will get me enough nerve to go back out and work on my Z.

I have a 1989 5.7L IROC that has had a surge condition for a long time, after it has warmed up. Never had any real stall issue, or shutting down, just a surge (best I can recall around 500-700rpm) when warmed up.

I have tried a few things here and there. The car only has about 65,000 miles on it, so it hasn't been driven alot. Therefore I did do a few usual checks and tune-up items, without any luck. But after reading about your luck with injectors, and how to ohm check them.......

I went out tonight and checked mine. The car hasn't moved for about 6 months. Here are the readings:

#1 = 16.5
#2 = 16.4
#3 = 15.7
#4 = 16.4
#5 = 26.4
#6 = 16.5
#7 = 16.6
#8 = 16.4

I have read a few threads where some of you have had issues with one of the injectors reading low. Now my #5 reads high. Is that my sign of injector failure? Yes, these are still the stock ones.

I have had a set of injectors on the shelf, as I had previously intended to go there next, but kinda lost faith in anymore fixing attempts, and tired of throwing parts at it. I beleive that I had ordered a set from south bay injectors, IIRC.

Anyway......any thoughts??!

I have a couple of questions:

1. Should I post specs of what was done to the car of what the previous owner did to the car, and what I've currently done to it?

2. What exactly is a "Integrator" and the "Block Learning Multiplier"? I know what most of the other stuff is, but I really don't know what those are. If anyone can, could you post a small description on both? Would greatly appreciate it.


Here's my plans, and I'm gonna hope for the best. I'm gonna try my best at not just "shoot arrows in the dark" and try to tackle this damn thing head on. I read the posts from the first post, all the way down to the one's I posted on this thread. Here's what I plan to do:

First and foremost, I want to get another chip, preferably a prom that matches the 350 rather than the 305 chip I currently have in now. I read that the 350 WILL run with the 305 chip and I read it WILL NOT run well with the 305 chip. My concern is, I don't want to do any unnecessarry spending on a chip I may not need.

Second, I plan on taking the car to the shop and having these checked out since I really don't have all the equipment.
- Check OHM's on injectors, even if they are new
- Check BLM
- Check Integrator
- Check 02 readings (what are ideal 02 readings for this engine?)
- Check TPS
- Check the IAC

That's my strategy. I'm hoping that stuff eliminates what I have going on and solves the problem. Does anyone have any suggestions on what else I should have done to it to diagnos it?

All help is greatly appreciated!!

Keep the thread alive and help out the fellow TPI owners who are also experiencing this hell!

Anyone know what the 'general' (ohm) tolerance should be between injectors??


+/- 10%, or 2-3 ohms from each other, etc.....

Too high....

Sweet!

I'm on vacation next week, but I am excited to get these injectors in the car afterwards. Man I would be soooo happy if this thing would run great again!

Hey Street Lethal or MaxpowerTA, any suggestions on what else I should do?

Also, not sure if I could fit this in here, but I was looking at getting a Hypertech prom chip from Classic Industries. Are those reliable, or would I be better off on finding a stock prom chip?

My 91 305 tpi has developed a similar problem. It surges and wants to die at lights. The difference is that within the past tank of gas it has Fuel Injector Connection injectors installed, a new fuel pump installed and for a whole tank of gas it ran fine. Even though it is having problem, my check engine light is not coming on.

on my '90 5.7L ECM chip, there's a setting in the PROM binary file for cylinder volume. it's set to 713 cc/cyl. i think that's how the chip knows the engine size. there's also settings for injector size, and number of cylinders. amongst other things.

but then again, my car is a speed-density, not MAF.

Yeah theres a link to show how to check and 0.5 ohm is said to be the tolerance, and I believe that good injectors should about 16 ohm's....Hope that helps....

Not much of a question, but just a little update.

This week I plan on getting a adapter chip for the 305 (with all my specs on it) along with the 350 ESC and knock sensor, and see if that rules out my question on what's going on. From what I last gathered from my mechanic, I was running a little on the lean condition.

I am really thinking my cars issue is vacuum related. I unplugged my brake booster and plugged the hose off and the car runs stronger and when warm, the idle goes back to where it should. Plugging it back in you can hear a very slight hiss. So I am going to change that and see how long the smooth idle lasts.

Injectors from fuel injector connection fixed my problem. Now I am going to sell it. Should be on here tomorrow.

I just wanted to say thanks to everyone in this post and of course this board! I had the same exact issue and been stumped trying to figure it out. More importantly, the link to FIC was way helpful. I just ordered a set with priority shipping so I can hopefully get this done over the weekend. I was going bonkers trying to figure out why after replacing the TPS (got it wet cleaning the engine ), the idle would be fine until it warmed up. I haven't done an OHM test, but I will later today. Regardless, I have all original fuel injectors so might as well swap them out. The engine has just over 2k miles on the rebuild. I'd love to get my tires barking again!

Great thread!.....I got the surging, hard start engine miss shuffle going on too.....the mechanic says the fuel pressure is good and constant...I remember the day I was driving along engine running great, typical sharp TPI throttle response as it has had for years then in an instant its like it suddenly developed a dead cylinder.....the mechanic says an "injector flush" might solve it.....are there any 'pour in the tank' type fuel injector cleaners worth even trying?????.....I checked out the vid I'll ohm the injectors tomorrow...Doug
oh.... 89 305 TPI 5spd Iroc

I don't know which "off the shelf" cleaners work best, but the dealers use a system that connects directly to the fuel rail and the fuel injector cleaner runs through the injectors from there at a high pressure. Its suposed to be good.

I have a complete similar problem as to you.... At start up it idles great, as soon as it warms up, it idles rough.

At a normal take off from a stop light, it hesitates and feels like it has a major miss. As soon as I get up to desired speed you it runs decent to where you couldn't even tell if something was wrong with the car. On the freeway and at higher speeds there nothing with the car at all.

Another problem is when idleing for too long or after being driven for over 20 minutes or so there's a strong fuel smell but there's no leaks anywhere.

Within the past 2 months I have changed External Coil, Ignition Module, Cap & Rotor, Knock Sensor, Fuel Filter, Spark Plugs, MAP Sensor, Oil Change, Radiator Flush, EGR Valve, Fuel Pressure Regulator, Oxygen Sensor, Engine Coolant Temperature Sensor, Air Intake Temperature Sensor, and Fuel Injectors (Bosch III's). All parts replaced where OE replacement AC Delco from the Dealership.

Man I'm so Lost right now and so close to being broke

My 89 Firebird formula 350 runs good cold but it start missing when it gets warm and looses power when it warms up and it has backfired several times it started doing this all of a sudden. I have changed the plugs,plug wires,dist cap, dist. button, the est, the O2 sensor, Fuel pump, Fuel filter, the ECM. I have run to my end with this can anyone help me with this.

It also smells like the fuel is very bad but it is 93 octane just like it is down a cylinder and not burning all of the gas

I am fighting the same thing as you right now, and have changed everything like you have. I am at a loss. Link to my thread: http://www.thirdgen.org/techboard/te...idle-dies.html (Surging at idle, and dies.)

Did you check the fuel pump? I had the same issue once, turns out it was my fuel pump going out. They don't always just die, they can slowly die out like mine did. I was stupid, rebuilt my upper intake system for nothing only to find out that the fuel pump was bad. I had to pump while cranking it over (its FI, not carb), was very hesitant when giving gas but ok when at higher speeds where the speed was consistent. Hope this helps.

Maybe your timing is way off. Any non-stock mods done to the car?

Fuel pump was just replaced and pressure is good. All stock motor. 305 tpi. Timing was just checked and set. The link above shows what I have done so far.

Do you have access to a Snap-On scanner or even a Tech2?
If you've changed that much and still have the problem, you need to throw it on a scanner and NOT a code reader.
That should save you some money.

My issue ended up being a mixture of timing and fueling.

I do not. Are they rent-able for auto parts stores?

I dunno.
You could download tunerprort (search on here for the website) for free (donations always welcome), but you'll still need a cable that you can get from www.moates.net

changed my ECU tonight and it corrected it. bought a re-manufactured one off ebay. Finally can drive it without being scared of it dying every time I stop!