ok, this is happening to my 95 vette... have just today replaced the following:

New GM optispark
new msd 8.5 wires
MAF
IAT
MAP
fuel Injectors
plugs
O2 sensors
Water Pump
fuel filter

problem still exists.... I am wondering if the injector drivers in the PCM are the culprit as i am out of things to check.. the car is my wifes and has an ed wright tune, no cats, AIR systemremoved and programmed out, EGR removed and programmed out, I replaced the exhaust sytem with the stock exhaust connected to the long tube headers and patched some exhaust leaks.... the car ran perfect for about 2 days and then went back to its same routine. i did disconnect the battery for this for about 6 hours as not to effect the PCM from any of the welding we were doing underneath. i read that this cleared up someone elses problems temporarily. so i have unplugged it again tonight and will reconnect it again in the morning to see if it clears the problem up. any new finds on this situation... and how did the injector drivers from the new PCM work?

Chris

 

I saw in a post, a long long time ago, that someone had this problem with the car stumbling around 2500-3000 rpm, and happens mostly around 80km/hr (or 50 mph) just as its around to trigger the converter to lock up.... What that post referred to was a wire to the tranny not working correctly ad for some reason was causing it all to bugger up and feel like its stumbling...
The guy thought he had the same problem as everyone else and said it fixed his "stumble".. I don't know if this is your problem, but it seems like youve replaced every darn thing relating to it.

My car STILL has this problem, it only happens around 80km/hr for me and ONLY happens when accellerating slowing (quick acelleariton works fine unlike most other pples problems). I have replaced darn near everything but have not tried this transmission wire thing... I cant find that post any more

 

ok, the car is an M6 manual I'm dealing with....

I took the car out just now to do some data gathering... car runs perfect sometime and for a while with no regard to anything from what i can tell, just starts running right.. then it will suddenly develop a miss.. backfiring... stumbling and blowing black (VERY RICH) smoke out the rear.

using PCMCOMM for viewing data, the Integrator for left and right look right at about 126-130 for both while driving... when the problem starts up, the left side remains at the above stated level and the right side climbs to a peak of 195.. it stays there unless i come down from tps percentage to idle. and then the car runs fine until it begins to climb.. when it gets to around 150 the stumble is very noticeable.. at 195 it is unbearable and i feel like i could be shaking something apart. any one out there ever log any info and find something like this? everything else was looking just right! any help?

thanks in advance,

Chris

 

My integrators and cells showed way high too like yours indicating lean too... happend ONLY when hte stumble happens... otherwise the blm's were fine...

 

Any suggestions as to what brand/type of opti-distributor to purchase. Delco or other????? pros/cons..

 

For the money you cant go wrong with a new factory delco one, if you get the aftermarket you'll be paying out your A$$, and wont gain much....but whatever you do DONT get a rebuild its not worth it, just consider the amount of work you'd have to do to change it, if it failed..........

 

Sounds like the opti is locking up mine did the same thing it would drive out normal sometimes and then others the bearing in the opti would lock solid its not a hard job just a time consuming one i would also look into relpacing the water pump when you do the swap because it prob has never been relpaced and you have to remove it anyway

 

my car is doing this same thing it totally embarassed me the other night while out crusiing, this mustang wanted to race me, and my car started acting so stupid it was hesitating, and even when i had it floored it was jerking like it was struggling to go.... i was told the opti was bad a year ago but now i think its really bad. it only does it after it warms up and after driving about 60 miles or so. could someone tell me where to get a opti at, and not dealership prices..they quoted me $1000 to change the distributor, i thought that was BS. it was like 600 for the part..and 400 for labor. also anyone know of anyone in indiana that could put it on????

thanks

jade

 

I have a 1995 z28 camaro , and for 8 months ive had to replace many parts just like you all, egr valve, o2 , opti, plugs and wires, but for the most part everything still made it run like ****, stumble idle , was never fixed....until it just completely died on me....problem was the fuel pump!! it ran great in the cold then when it got to running temp it started to stumble in low 1k -2k rpm range.....that might be your problem...fuel pump.... and for the labor on the opti....4 hours my first time doing it!! its not that hard....a few sockets hear and there, waterpump , and walllah!! your there.....

 

Jason Cromer 1800-243-8826 , Dealership in florida 299 for original opti.10 or so dollars shipping. The following is a website that has good directions and pics and tips to replacing the opti. http://www.streetillusionsracing.com.../opti/opti.htm I just did it. It was cake. Just remember to triple check everything. And replace water pump at same time 130 dollars. If you have any questions about the replacement email me through akobak@kent.edu and ill give my # for phone info if needed. I got my opti in akron for same 300 dollars either way good price. I'd check all plugs and wires too. The plugs and wires are harder to replace than the opti though. Ive done plugs and wires before and still had a wire that wasnt connected all the way. Like I said triple check everything when doing any engine work.

 

I have a similar problem.

Time to revive the thread!

My airfilter was ditry could this gunk up the MAF?

-Dustin-

 

Borderline impossible But you can clean it for fun, may help a little....

 

instead of opti replacement, can one do delteq instead?

 

OMG sounds like everyone has this problem. I was starting to think I had a ghost. My problem is a little different tho. The car wont stay running from a cold stat. it turns over then dies. You have to hold down the gas for about 10 seconds till it catches idle then you have to let it warm up for about 5 to 10 minutes or it will die if you put it in gear. the other problem is it hestitates under load. it sounds great when it idles but once you put it in gear and start to go its like it wont go when you push the gas. Once it warms up it does fine. It will even start right up after you have driven it for a while and dont let it get cold. But lately it has started acting up more. When I turn a corner its like it starts to cut out almost like it wants to die, then when i push on the gas it boggs out til it catches up to speed then it runs ok...we have spend 3500 dollars in the last 6 months and 5 different mechanics and no one can figure this out. we have replaced the O2 sensors, optispark, water pump ingnition module, computer, MAP sensor. the last mechanioc suggested the fuel pump cause when he tested it he said it only got to 37 lbs. but i have read so many blogs that i dont know if thats it. the only codes that have come back now are the oil pressure sensor and the knock sensor. the mech said he put a new knock sensor on it but it didnt change anything so he took it off. Please if anyone has any suggestions

 

what year car, trans? where you at? temp outside? need more info