cany figure out miss, stutter or hiccup????

[1985GN]

i have an annoying miss or hiccup or whatever it is that recently came about at WOT on my car. my car was off the road for about 1.5 months while i saved for a tranny and while it was off i put a eastern perf FM on too. after i got it on the road it had a miss when i was on the car hard so i bought new plugs. the old ones were loose and had a .37 gap which was too big. i gapped them down to .34 since im running 20psi of boost. it seemed to go away and the car was running good but every once in a while it would come back just a tad. well i let it go and it seemed to stop till the other night. car ran great the night before so i turned the FP down 1psi to see if i could lean it a little more. took the car out and it was mising/stuttering at WOT. i put the FP back up 1psi to no avail. as the night went on i was testing stuff out and wehn i got on it one time the IC hose popped right off so i figured get it all on right and i figured out my prob.......wrong. so now i checked the FP it rises with boost, new plugs, 4 month old wires, new coil pack and module, MAF pins 255, all IC hoses tightned down. could putting hte FM on leaned the car out more then i think and thats is causing the stutter. i also have no knock maybe 2 degrees every once in a while when doing it and this is at 20psi. the only thing i noticed is the other night when getting on it the BL was at 105-108 when it used to go to 128?? any ideas would be great guys i dont know why it ran fine and then all of a sudden did this. any ideas on where to look on this it just popped up out of nowhere

 

[opzWE4]

Did you get any codes? Mine had an intermitant stutter or hiccup that I could not figure out, but I eventually changed my ECM and have not had it occur since. BTW, I was getting a code 42 sometimes also, but it usually did not occur at the same time as the hiccup. Hope you figure it out, I know how irritating it can be.

 

[MARINES185]

my car would do the same thing. put it to the floor and it would
start to rev up then it would start missing and backfiring. turned
out to be a weak coil pack. I know this for sure because i had
the old coil pack tested.the resistence across each coil pack
should be arond 12 to 13 thousand ohm's. this will not always
pick up problems as my coil pack did show its weakness until
it was under load. most local garages should have an ignition
scope to test it for you.

 

[TURBOTIMMER]

Have you tested the new coilpacks? I went through a couple sets before I found good ones. They both came right out of the boxes from GM. I've heard of people besides me having problems with brand new ones.

Just my .02

Good luck

 

[1985GN]

ok i have some new info. to begin with the coil pack and module on the car is about 4 months old and i bought them off of Red Regal T on this board and htey are tested good. ok i went out and was snooping around and made sure the plugs were all tight in there holes. before i did the i took them out looked at them and noticed there were sotty which i expected since i drive the car about 7 blocks with the IC hose off last night and was buring raw fuel. ok so i gap them to .32 and put them back in making sure there snug and making sure the wires are all put on right. i take the car for a ride and it seems to be a little better. i take the car for a ride farther and get on it misses a little up top still and then when i get off its really missing. im cruising in OD and hten D and its hesitating and all like its runing on 3 cylinders. i try to get on it and the thing cant even make a pound of boost. its spittting and stalled at a lgiht. at light throttle i can drive it wiht a slight miss all the way home. if i get on it it wnats to stall then sometimes it stutters real bad then takes off liek a bat out of hell. im thinking i fouled some plugs and i should put the gap back to the stock .35? i cant even drive the car right now any ideas?? im guesing the prob maybe plug related?? thanks guys

 

[TURBOTIMMER]

I had a similar problem with my GN a couple weeks ago. Do you have it hooked up to a scan tool when this happens? If so, what's your 02 voltage at?

 

[TurboDave]

Might be time to start thinking about looking at the MAF.

 

[TURBOTIMMER]

TurboDave, you took the words right out of my mouth. When my maf went bad, my 02 numbers pretty much locked up at .95. I started my car up, let it idle, and tapped on the maf. When I did, the motor would immediately start to miss.

 

[1985GN]

ok here is some new info...... i bought new plugs and gapped them to the stock .35. i started the car up and took it for a ride. right away it started miss and stutter and not make it over the 0 on the boost guage. i look at hte plugs and they are all sooty. then in park i was revving the car up real high and holding my foot on the gas while it would start to miss and everything and black smoke was coming out of the exhaust. looks like its dumping alot of fuel?? any ideas how can i test the MAF. before this happened the thing pegged 255 on my scanmaster. im fustrated on this one........thanks for all the help guys

 

[1985GN]

ok even more of an update. i went out and out of curiousity i went and found my old MAF that had a bad stumble when i was on it up top and i switched it out for htis on and the prob was solved. i hooked this one up and went for a ride and now i can get boost and everything and no miss excpet up top like it had before. this MAF that i had on i bought from either cotton or conley and i was told there has not been one that went wrong. i have had the MAF for about 8 months and its completely shot??? with the known bad one in the car now i can at least drive it and i cant understand why it pegs 255 when i get on it yet it dont work. if a MAF pegs 255 can it still be a bad one?? thanks guys im hoping this is it