88 Iroc-z 5.7 TPI My cars performance has declined over the years and eventually wouldn't run with the MAF plugged in. With MAF plugged in car will idle very rough shaking harder than a 50 cent hotel bed and run so rich it burns my eyes and given any throttle will die. With MAF unplugged car runs good but I know it would run better if I could find my problem. Things I've changed MAF, TPS, EGR, Oxygen Sensor, ECM, Cap Rotor, Sparkplugs, Fuel filter, maybe the IAC cant remember. Things I've checked sprayed starting fluid all over checking for air leaks, Timing, MAF harness, Various MAF wires looking for shorts. Things I've upgraded Borla cat back exhaust, Hypertech chip, B&M ratchet shifter, cleaned the guts out of the catalytic converter. I'm no mechanic but if pointed in the right direction with all the knowledge on this site I know I will figure out my problem.

 

try changing your maf relays. i think code 33 means low voltage at the maf sensor. so maybe the power relay is toast. there should be 3 relays on the firewall by the brake booster. 2 are for maf sensor and 1 is for fuel pump.
hope this helps

 

Just got done changing both maf reay and the burn-off relay. Crossed my fingers and started her up idled good for about one sec then started running rough and died. Tried a few more times with the same results given any throttle at all she just cuts out and dies. I'm so bummed I dont know what to try next.

 

try hitting the maf with a spoon, if idle dies/ or is rough its the maf i just replaced myn fixed EVERYTHING, Also becareful if yours was faulted like myn, It may burn out that new burn of relay

 

What is the TPS voltage at closed throttle?

 

Since you changed the relays already, I would clean the MAF sensing wire with brake cleaner with the MAF removed. Make should it dries completely before reinstall.

Also, if you had recently oiled an air filter like the K&N type, that could be the cause of this issue.

Finally, what are all the mods down to the engine?
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And, like Vader asked, what was done to set the idle speed and minimum air?
what is the TPS voltage?

 

Not real sure how to check the TPS voltage but will explain what I did. I checked everything with just the key on. the gray and black wire with the sensor unplugged read 5.03V when plugged in read 5.02V. The blue and black Wire with the sensor unplugged read .04V when plugged in read .57V. There has been no modifications done to the engine other than having a head gasket supposedly replaced by the local dealership. A week after they worked on my car the service engine soon light came on with the problem I have now when returned to them to find the problem they more or less just laughed in my face and this was 6-7 years ago. The car has since been taken to various mechanics with no success. I don't run a K&N filter and the MAF was replaced when that didn't work I returned it for a new one and has since had various new MAF plugged in. The car has 46,724 original miles on it and I can't imagine the wire inside the MAF being dirty since it was replaced about 3,000 miles ago. I'm not real sure what you mean about what was done to set the idle speed and minimum air.

 

Just got done setting TPS to .54V looked like that's the magic number from reading posts at half throttle reads 2.29V and at full reads 4.06V. Started car up and seamed to idle a little better and even got to rev engine a few times before it died. Started up again and back to square one with the idle a little better but still rough and dies when given any throttle. Scratch the code 33 it was so long ago I don't really remember what code it was when I first started having my problem I just know it was one for the MAF. The code 33 could have just been set from me running around with the MAF unplugged. I disconnected the battery when I replaced the relays and erased the codes and it hasen't set a new one.