I have a 1988 Iroc with a ZZ4, LT4 hot cam kit(.525 lift), stock tpi, 24lb injectors, removed cat, air pump, and cold start disconnected. The car ran extremely rich and I got a chip for it from tpichips.com. The chip leaned the car out a bit but I still need to adjust the timing and fuel pressure. What is a good base to set my fuel pressure to? How much should i advance the timing? I am not worried about performance or fuel mileage i just want the car to idle, cruise, accelerate smoothly, and not reek of unburnt fuel out the exhaust. After i installed the chip, the car accelerated smoothly but i have to tach it up to nearly 3000 to let the clutch out and i never did before. When i idle it almost seems as if the car loads up. My timing may be retarded a few degrees but i want to make sure i am diagnosing the problem in the right direction(never put a timing light on the car yet). I plan on installing a 3 wire heated oxygen sensor and putting on a new CAT. Will this help me or hurt me? The car has a 5 speed manual transmission and bucks badly when shifting without heavy acceleration. After idle for a period of time the car begins to surge at idle but after installing the chip this has greatly improved. I am trying to get the car done so i dont have to sell it and can drive when i get my license in august. I am only 16 and have had the car for a year. Let me know of everthing that i can possibly do to save the car without spening thousands because i will sell the car for a stock iroc before i do that. PLEASE HELP ME. FUEL INJECTION IS COMPLICATED! thanks. Joe.

 

Welcome to TGO. I'm having the same problem with my '89 Iroc. It's got an LB9 w/ 700R4. I was told by the previous owner that it had a mild cam in it, but I dont know what cam or how mild. My car has the same symptoms as your car. Mine still has the cat and all the emissions equip. hooked up. It has Edelbrock TES headers and Flowmaster catback exhaust. Hopefully Five7kid(moderator) or some of the other members will chime in and help you and I with this problem.

 

I hope to get some reliable tips on what to do also. Thank you for your input and the welcome. Does your car still smell of unburnt fuel with the CAT?!?

 

Yeah, the old girl runs rich with the cat and emisions hooked up. The car hadn't really been driven for almost 2 years. It ran really rich when I first got it, but since I've been driving it it's gotten a little better. She still idles rough though. The car accelarates and cruises fine, but idles like it's got too much cam in it. I need to check timing, EGR, O2, MAF, and TPS. The only other thing I can think of is to put a vacuum gauge on it to see where the vacuum is and then get a chip for the ECM.

 

yea my car made you nearly pass out at a light no matter what wiht the windows up or down. The guy i bought it from had 42lb injectors in it!!! little much? it used to drive much smoother then but it smelled so bad that you would nearly black out at a red light so i put in svo 24lb'ers I'll work on itnthis weekend and see what happens then do the exhaust work from there. Thank you for you input. Hoping to get more info though.

 

I Aswell had a RICH problem too.. Soo Rich that I Wrecked of unburned fuel after i got out o the car.. There a few things I want to state that I have found in my path to getting rid of this problem...

1) If you have a " Piggy Back performance Chip On your TPI" and you have or dont have a service engine soon Light, try taking it out and putting the O.E.M Chip In alone.. this solved all of My Problems with the car running like crap, Vibrating and shaking and stinking of that smell that could Kill a pack of birds flying a houndred feet away, haha...

Not Only was My chip Faulty But it was Put In the wrong way ( which caused the Sevice engine soon Light"...

Car Runs Great Now, I also replaced the O2 sensor aswell, When that car ran Like that there was alot Of carbon build up.. I also Changed the plugs out..

By the way.. I still get a little tiny hint Of the unburned Fuel Smell.. I want to say for sure its On account of Not having a Cat But I could be Wrong. because My GTA has Duel cats, and when you tap them they sound pretty hollow so they may be staged there. But what leads me to beleave that the cat is responsible for the smell is that I also have a 2001 pontiac grand Prix GT that I recently Put a Straight pipe In and eliminated the cat.. when I did that that smell came, and its not because the rear O2 is unplugged either, the rear O2 is responcible for telling the computer what kind of job the catylist is doing ( my fuel economy has never Changed).. just the smell of the exhaust..

FROM WHAT I HAVE READ Taking the cats Out of the Duel Cat Equipped f bodies is pointless.. I Have read that the cats Give 10 More horsepower. i dont know for sure, but when i order 2 new cats ill be sure to let you know if the smell went away and if shes got more pep..

my grand prix lost alot of torque when the cat came out.. so that one will be getting a new one too

 

I have a tpichips.com mail order chip and i understand what you mean about putting it in incorrectly. I used to run the car wiht the O.E.M. chip and it reeked much worst and did not have as much power. So far i have been going in the rihgt direction in everyhting i did. My car is a single cat car and i plan on replacing the cat wiht a new high flow one. I was worrier about losing horsepower but now i am happy i am putting it back on other then losing that sound i have now.

 

I believe my chip is stock, but I havent dropped the ECM yet to take a look. I plan on replacing the O2 sensor, and maybe the TPS tomorrow. Hopefully that wil take care of my over rich and rough idling. Other than that, the old girl runs good and gets 27-28 mpg on the highway and 19-20 in the city.

 

My Chip was a C-jet Chip With a Date label of 1993 on it.. I still have it and Was going to send it to this Guy who reprograms chips for $80.00 for some personal tunings i have in mind . Only thing I Like about that Chip is it made BOTH of my fans Turn On at a lower temp and it did have more power.. But that smell,No way.. also my fuel injectors made a funny buzzing sound when that chip was in, adn I think thats what killed the old injectors, they started going 1 by 1..But I want My GTA for its Looks, Not who's got the fastest car in my town. Although who am I kidding that would be Nice. I get people all the time saying ( Ohh u think my M3 can beat your car)..haha.."Im not 17 anymore, Im 23 with good Insurence rates for 2 cars under my name, and yes The nice M3 Mommy and Daddy Bought you could Probably take my nearly 4,000 lb Slug..lol"

However,My GTA HAS taken a Acura TL for a good Run... .. it seems those TL's loose their steam once they get upstairs, or it could of been the driver, who knows...

 

Hey Do you have a Multi Meter?... TPS are expensive O2's are pretty cheap and it would be worth it to do, just make sure you have a good crows foot wrench that attaches to your extention, better yet the O2 sensor tool you could pick up at usually any auto parts store, Unfortunatly I get stuck working On not only my own pontiacs, But My friends cars too.. so In my case I purchased the tool from my tool guy, if this is gonna be a 1 time deal for you autozone rents tools.. save you some money..

Oh yeH the multimeter.. if you have a good digital multimeter Check the Voltages On the TPS before you replace, that may not be the problem and can be waisted money.. preventive maintnance sounds good But Now may not be the time, for that anyways... TPS should be adjustable, and should measure .54 at IDLE... if its different First Check and see if you do have one of those Chips, because that could Explain why its different... If you dont have the Chip and it Dont Read .54V Move the throttle with your Finger, at full throttle it shoud read 5V.. if the readings are No where stable then replace it

 

Also, Check this Out.. The Info I gave you I learned off this site last year when i was testing ALL of my sensors.. Check it Out Im sure it can help you


http://tpiparts.net/home


Look In the TEC articals.. i dont remember what Year you have But I have the 90-92 Speed Density....

 

Hey dude, check your coolant temp sensor. If it shorted out it'll tell the ecm thats its -45and richen the fuel very badly.It'll cause all the symptoms that you are describing.

 

Thanks for the info. I went to tpiparts website, lots of good information. ZZ4IROC, check this site out, unless you've already been there. I planned on checking the voltage on the TPS before buying one, thanks for reminding me though, 905SpeedGTA. Now if I could only find good used 85-90 Z28/IROC fenders as easily.

 

I forgot all about the CTS. I remember reading about that being a probable cause for my rough idle/uber rich woes. Good looking out bgood71. See ZZ4IROC, I told you other knowledgeable members on this site would chime in with valuable info and links to other helpful sites. Dont give up on that IROC yet. As long as you keep posting and asking questions(and occasionally researching old threads) the TGO community will be here to help you. I've said it in previous posts and I'll say it again, TGO is by far, the BEST website dedicated the 82-92 3rd gen Camaro and Firebird, period! Thanks again to all who have helped me and others.

 

Your welcome man, anytime.. Ive been thu alot of diagnostics with my car and I figured stuff out along the way and Learned alot..

I need a Passenger fender BAd.. I cant save that Crap.. its not worth it...My Buddy is still parting Out His 89 rs or Iroc I dont remember what it was, the black one In the Pics i put in the post about my flooded Interior...hes a pretty much " make me an offer guy" ..

P.S - Dont use those analog B.S Voltmeters.. They are junk and lose calibration after a while get a nice Digital one

 

wow i should have posted this question a long time ago! I don't think its the temperature sensor though because i recently pulled the intake because of a bad oil leak at the back of it under the distributor. When i did this, i left it unplugged and it took two weeks of troubleshooting and playing with the timing before i figured that out. I will most likely but a new sensor anyway just to eliminate that from my list of possibilities. Thank you for all your help. I plan on adjusting the idle, timing, and fuel pressure tommorow which will most likely change after i put the CAT on and heated O2 but wish me luck. I'll keep posting as I fix my problem to keep anyone with a similar problem updated.

 

ZZ4IROC - I would Say Check that Sensor for fault Before you proceed, But Just Like the O2 Sensor, Its Cheap... Just make sure you do this when the engine is warm or cold, Because when you take that coolant temp sensor Out its gonna Squirt haha..

I got a Question for you.. What Did you use to solve the Problem concerning the bad Oil leak in the back of the Motor.. I Put My Engine Back together and The gasket set I got told me to Put a Liberal amount Of Silicon On that, I did But there is a Leak...What did you do?

 

I used international grey silicone to seal my intake. They use it on diesel motors for the oil pan etc. It is so strong that it smokes it dries! Good luck with alll those intake bolts.

 

To seal the GM intake ends, toss the end seals and use either Ultra Black Silicone or The Right Stuff. The cork end seals alomst always leak.

 

I replaced the O2 sensor, and she's not running as rich now. I'm going to check the voltage on the TPS today and see if that takes care of the rough lopey idle. If not , I'll move on to the coolant temp sensor. If that isn't it, then it's vacuum gauge time!

 

PM sent

 

Well, I just pulled the trouble codes from my ECM. The old girl tripped code 13 and code 32. I replaced the O2(#13) and I gotta check the EGR vacum line and solenoid(#32). Anyway, it looks like I might be yanking the plenum and runners of to get to the EGR if it has to be replaced.

 

yea i tuned the timing, set the IAC and was very smooth for about a day...then back to the rough idle. I have the high flow CAT and o2 sensor on order to try to get a smooth idle although i do have my EGR removed (my heads are blocked off). This idle drives me crazy!