sputtering 7mgte any help?!
 

i have a 90 7mgte with the basic bolt on running stock boost. my problem is, yesterday it started missing like it was running on 5 cylinders. It did this once before about a month ago but i parked it for the night and it ran great in the morning. NOTE: it's FREEEEEZING OUT here in central pennsylvania!! i pulled the wires off the coils one at a time to see if it made a difference. Odd thing is it almost stalled out when i removed each of the 6 wires which means they were ALL firing. I know what a car sounds like when its missing on one cylinder my Celica did the same thing and its wires were shorting out....and this sounds just like it. It started doing this only at full boost....and then only when you gave it gas.....and now it even does it at idle....im just confused and hoping someone more familiar with the 7m has maybe seen this and knows what to do. - thanks for any help o yea side note....already has HKS MHG and does NOT use coolant so i dont think it a BHG.

Any diagnostic codes stored?

sputtering
 

No codes as of yet. If it werent so damned cold out i could probably diagnose the problem but I know these cars problems are well covered by their niche market of owners and i was going to go the route of asking and hoping it was something common before suiting up and enduring the freezing cold for god knows how long. i have a video of the problem as soon as it uploads

video of problem
 

don't make fun of the orange wheels i needed something for snow tires
http://www.youtube.com/watch?v=0fmuSSP0Rv4

EDIT: n/m, saw your not about no codes

sorry i typed no codes but it somehow didnt insert it in my post. i had to edit it. ill check one more time cuz i know there can be codes with no light.

Check for split intake couplers and other leaks, check for oil around plugs, check plugs... that's where I'd start anyway. How's the timing look?

codes
 

pardon my previous ignorance i stand corrected. 4 count 'em 4 codes. 21, 23, 31 and 34 sputtering seems to continuously getting worse every time i start her up.
i cant find any explanation for code 23 if it even exists im sure i counted 2 then 3 blinks but its looking like the MAF and O2 sensor signals are screwed up and the turbocharger pressure is reading abnormally. im going to check the intercooler piping and hope its not the ECU.

more info
 

o yea and the cam sensor (distributor) is turned fully to the "up" position as far as possible but it's been there since i got the car almost 2 months ago. and there is oil in the plug galley but it's so cold out i might wait til the garage is free to check the plugs.....otherwise i would have long ago.

Oil in the plug galley WILL cause misfires. Codes 31 and 34 point to a bad AFM; 34 point to AFM or boost leak, but with the 31 a bad AFM is a bit more likely. You should get the mechanical timing issue and spark advance all in order ASAP as well as poor timing will make other misfire issues worse and hard as hell to properly diagnose. The order to approach is: Get the oil out of the galley! Test the AFM, swap in a good one for testing purposes if possible, reset mechanical timing one ALL error codes have been corrected, set ignition advance.

I've never heard of code 23 either.


EDIT: Google turns up reports that according to other TSRM for other vehicles 23 is pretty much the same as 24... IAT sensor problem. So, you may have a wiring issue to the AFM or the AFM was unplugged while the car was running at some time. a bad AFM is still possible, but a LITTLE less likely as the IAT shares very little of the rest of the internal circuit of the AFM.

thanks
 

u know what i helicoiled and restudded the exhaust manifold the other day and when i was all done i forgot to plug the AFM back in when i first started it up. it was a week ago but it WAS unplugged for a minute or 2. im gunna put my coat on and go outside for a bit. THANKS ALOT for all the help and information ill let u know what i find.

You really NEED to get the oil out of the galley, especially since you've pulled the plug wires out with the oil in there... it WILL cause misfires.

it's 9 freaking degrees out
 

o no i pulled them off the coil but i agree it needs cleaned out. the 5 minutes i looked at it tonight haven shown me nothing but tomorrow i can put it in the garage and see. im thinking there is probably a broken wire somewhere in the harness that runs by the thermostat housing considering all of the sensors in question run by there. that or a bad afm. but until then thanks again for the help.

research
 

well in the morning im gunna check the plugs and for openings or shorts in the harness but i have a bad feeling. after looking at the tsrm troubleshooting guide, all for codes have one possible fault in common, the ECU. ill keep my fingures crossed and hope i just have to repair a wire or something but it's not looking good for now. even just the word ECU sounds expensive.

The ECU is a possible source for EVERY code... it seldom is the problem... unless you've been doing some creative wiring.

mostly solved
 

ok well i went out and pulled my plugs. 4 out of the six were DRIPPING WET with what smelled like dirt mixed with burnt oil. it does burn some so that makes sense. i cleaned the plugs off and removed any corrosion from the wires and reinstalled everything.......RUNS GREAT. better than ever. next month (ill be away with the army for a month) im going to get after it really good and do valve cover seals, oil galley plug seals, plugs, wires, and an oil change. thanks for the help i appreciate it very much. ill let u know if anything starts up again

Oil in the galley has nothing to do with burning oil (unless both are a symptom of a severely cracked head). The oil got on the plugs when you pulled them. Plugs come out and oil and dirt pour in. :(

I'm glad the problem was a simple one! :D