MadRomeo

I searched the forums on and off for a few months now on this problem and everyone seems to have a symptom or two different from mine.

Background:
I purchased a 1985 IROC with 114,000 on the clock. Wouldn't start, replaced the fuel pump and gas tank and started right up. Noticed an oil leak from the pan and front crank seal, replaced them. Had an overheating issue, turned out to be a stuck thermostat, replaced that, as well as the hoses connecting to the TB, and did a gasket kit for the TB as well. Drove it for 200 miles and noticed a coolant loss. Saw pooling in the intake and diagnosed it to be coming from the loose torx screws on the bottom of the TB (oops). After putting that back together, the s**t hit the fan. Normal high idle on cold start, then gradually rises the closer it comes to operating temp, maxes at about 2k. Threw a check engine light code 33, (might note at this point that after I noticed the coolant leak from the TB, there was coolant in the intake) and replaced the MAF for the first time. No change, checked for vacuum leaks, came up with nothing, replaced IAC and attempted to set idle, nothing. Tested the MAF, turned out to be a bad sensor out of the box, went through the same procedure again until testing ANOTHER sensor and finding it bad. Ordered a new Walker unit and it tested fine before reinstalling. Still had no change and the same code popping up. I tried replacing the relays and splicing in a new pigtail. Then, all of a sudden after I had arrangements made for long term storage, I started it to drive on the trailer with no problems. Achieved proper idle at operating temp for the first time! Drove it around the neighborhood with no problems. Went ahead anyway with storage. And so it sat.

Went to start it for the first time in a couple weeks and the check engine light came on again with the same symptoms. I haven't checked to see of its the same code, but I would assume it is because of the exact symptoms I had previously. I noticed in the storage shed that it smelled pig rich. I stumped at this point.

Where should I start, I was thinking about my cold start injector being the issue, but I don't know if my logic is sound there? Any help is good help at this point. Thanks

Update: I completely forgot I started a thread earlier about the same issue a few months back before the second MAF replacement. My apologies everybody

Tuned Performance

iTrader: (92)

Malf code 33 triggers 1/4 throttle or less above 45 gps.
You might have a bad ecm . Have you gone through the flow chart for code 33 ?
http://www.chevythunder.com/maf_code_33.htm
I don’t think it’s a cold start injector issue. Here is a flow chart for the ninth injector.
https://www.thirdgen.org/forums/tech...atic-only.html
Sounds like a vacuum leak maybe a smoke machine might need to be used.

MadRomeo

I haven't gone through the chart yet, but I will when it comes time to pull it out of storage. I was actually hoping it would be a cold start injector problem, that way I could delete it... Oh well. And if I couldn't get my hands on a smoke machine, are there any good substitutes?

Tuned Performance

iTrader: (92)

https://m.ebay.com/itm/EVAP-Smoke-Ma...8AAOSwxzBZm92S
There are a lot of diy instructions on the Internet/youtube

MadRomeo

Finally got around to doing the Code 33 chart, it says I have a bad MAF, but I purchased a brand new unit from Walker. Is there any resistance test that I could do to test the sensor itself? Someone else on here told me that if my oil pressure gauge is fluctuating, then a failing oil pressure sending unit could disrupt voltage to the MAF. Is that a possibility?

Tuned Performance

iTrader: (92)

The op gauge has no electrical connection with the maf.
I don’t know that there is a test for the maf other than viewing the grams per second data on a scanner.

Vader

The other test for a 1985 system MAF is to connect a diagnostic oscilloscope or handheld meter with frequency counter to the MAF output signal and measure the pulse width. This only applies to 1985, as 1986-89 MAFs used an analog voltage signal (0-5VDC) to the ECM to report air flow.

If you have been incorrectly instructed to replace the MAF with an analog output type, you may have found one of the problems. I've seen several web sites listing the same MAF for 1985-89 cars, which is incorrect.

Painless Performance gets it right. TPI Parts.net gets it right. Granatelli has it ALL WRONG, as do many other sites, like Corvette Forum and others. There is a LOT of misinformation out there. Some people have actually been able to get an '85 to run with a later MAF, but it is not correct. There is one thread in Corvette Forum that explained that with empirical data, but all the other mis-informative posts clutter the site.

Jp's camaro

I had a high idle issue on my 85 that would slowly rise to sometimes over 2,000. Ended up being a bad connector to the coolant temp sensor.