fivestar

My 88 Iroc z Convertible with a 305 TPI has run pretty darn good over the last six years (that is when I rebuilt the engine and trans). Just recently it has run a bit rough, I replaced the MAF burnoff relay and it ran great for another six months or so but now it is running/idling rough and sometimes stalls. I replaced the MAF burnoff relay (thinking I might have a defective one) again but it still runs rough. I was limping the Iroc home 3 miles and during the drive it smoothed right out...?? Drove it a couple of days and it was fine then again today I go out and start it and it is running/idling rough and stalls so I replace my fuel filter and gas cap and clean my MAF sensor. While I am waiting for the sensor to dry I start the Iroc up without the MAF sensor on and of course I get a 'check engine light' but it runs fine just idling high but steady/smooth 1800 rpm or so.
Reinstall my MAF sensor and plug everything back in and it start it up and it is back to running/idling rough and near stalling??! Seems to me the after 23 years the MAF might need replacing but I just wanted to make sure someone here might give me a little guidance. Those MAF sensors are not cheap and I do not want to replace it and find out that I just spent $$$ on something that did not necessarily need replacing??? Any thoughts??

Fivestar

blackbeauty89

chances are if you unplugged the MAF and ran the engine and it ran better with it unplugged than you'll need to replace it. same thing happened to me, only i was driving and hit a bit of water and the MAF must have gotten wet. i tried the same thing to make sure.

BlackenedBird

iTrader: (5)

Have you checked the CEL codes? Don't just start replacing parts, like the burnoff relay, just because you think it'll fix the car. Check the codes. Borrow friends parts to test with, if you can.

fivestar

Not getting any codes at all. I cleared the 33 code from the cleaning and re-installing the MAF sensor from earlier in the day. Did not have a code before removing the MAF-only got a code when I started the car without the MAF off... I did find a Remanufactured MAF for $125.00 The original Bosch unit is 23 years old and I noticed when I removed it the 'seal' underneath is peeling away so I think it might be compromised...
I also want to throw out that I think the EGR sticking

BlackenedBird

iTrader: (5)

For the extra $25, I'd buy the New one from Autozone. I was going to replace mine last week, but found my spare MAF I had tucked away 5 yrs ago when they were over $300!

fivestar

Yahoo!
Went out today and picked up a Reman MAF sensor from Autozone for $125.00 and fixed my rough running/idle problem. Put it in-took 10 mins and viola! Runs great and drove the Convertible all day with the top down just so folks could see the smile on my face. Thanks for the help!

Fivestar

transamgta1Khp

anyone know how to test a MAF for voltage problems? what should the reading be? just curious as i know the TPS has a setting and has a certain voltage of .54. is there any reference to how many volts a MAF is supposed to be with motor off and key on?

BlackenedBird

iTrader: (5)

https://www.thirdgen.org/forums/elec...f-wireing.html

https://www.thirdgen.org/forums/sear...archid=6298535

rusty vango

yeah,take it from me ditch the TPI and all its WTF moments while you can.OR there are cheeep MAFs but the quality is non existant. its 50/50 at best.OR a new GM MAF is $1093.but i find they are made for GM in china so ,go figure. and i thought "cross fire injection " was a mess. personally im going to scrap the TPI unit on my car.and go buy a carb and intake.sooner than later the TPI units wont run right and they all start that. wont run right with the CEL off, code 33,34 and 36 WILL be your constant companions.good luck

ZZ42Fast

iTrader: (2)

I disagree, everything is solveable. Process of elimination like all these things. I feel when you swap to carb you loose a big part of the car's dna.

rusty vango

i would have to agree,however the blank stares when you try to find a knowlegable garage/mechanic.the absence of quality replacement parts(think chinese) the constant problems that a almost 30 year old car has with its wiring and components.can get to a guy. i love the way the TPI looks, and when its right it gets phenominal gas mileage.but mine is a hit or miss ,mostly these days its miss. makes me re think all that .no im not ready to chuck my camaro in favor of,say a hyundai .oh youll laugh at this one,a "senior" tech at my local chevy dealership( hes 27) said to me recently".your cars obsolete,why dont you trade it for something new??" i could have smacked him into next week.and around here trying to find a OBD 1. scan tool is impossible.

nomind

I think I would "update" the car to ODBII before I stuck a carb on it, just my 2 cents.

rusty vango

i would love to, better mileage, smoother running. whats not to like?? but im afraid that conversion might be outside of my skill set

nomind

I keep coming back to the same issue. Especially since I've got the bastard of a TPI wiring harness from 85. That being said, there are people that would help, once you acquire all the bits, and its actually pretty well documented. When my MAF burnoff relay finally dies on mine, that'll probably be the way I go (or an LS swap).

kennypolatas

I have a 1987 TPI trans am. Can anyone tell me where the IAT sensor plugs in. I know its in the upper intake but i don't know where the two wires plug into.

Boogins

My 88 Iroc-Z 5.7 TPI will not tolerate any of the after market MAFs...I have purchased a couple used "Genuine Bosch" from online sites that have worked with no ECM errors over the years and ran them til they start shorting out like the original one did. Seem to control the "Personality" of the engine's characteristics more than any of the other related items like O sensor etc. I believe I tried 3 different Autozone Re-Man units, all graciously returned I might add "They Seemed To Have Differing Elements ranging from a single Tungsten rod to a small printed circuit board to one similar in appearance to the OE Bosch" and bought one that was "New" from them although it did not have the Bosch logo etched onto it's cover. I also purchased a "New" unit from an online retailer which I still have. All would either instantly throw an error code or would over the first 4 or 5 startups. I see the OE Bosch went out of production in 2012 and a few NOS are still available at outrageous prices "High $300s-$400" Has anyone encountered the same problem? This is probably the 3rd ECM unit that I have installed and I might add that I have used both the stock and Hypertech PROMs with the same result always a "33" and yes I have changed the burn off relay etc. Some the "Error" Mafs actually didn't run badly except that I know from experience that if an error is present the OBD system will eventually go into it's closed or "Enrichment" mode. Otherwise I would put a piece of tape over the Service Engine Light and move on. Looking for possible solution without purchasing another tired old one or a very expensive NOS unit???

Silversdark

so what you do to clear code 34