It started missing about a week ago, but only in the lower rpms. On the way to work today i noticed it got worse, it was missing throughout all the rpms. Then on the way home it back fired twice, both times around 2500... Plugs/wires are brand new... i just changed the fuel filter today (fuel in there was brown!) I also added a bottle of fuel injector cleaner but i dont even know if that really does anything.

Anyone have any tips? I need to get this fixed asap, i do not like riding around knowing something is f'ed!

Any help/suggestions are appreciated.

-Robert

 

Get it scanned but it sounds like the opti-spark. My car is doning the same thing. Winter project for me.

 

nobody else has any input?

The problem seems to be getting worse, if i drive at about 1500 and stay at 1500 the rpms will bounce up and down, not alot but u can definetly see it and feel it. Accelerating from a dead stop is the worse, it misses so bad just slowly accelerating.

I did a fuel/motor clean today, (think it works like sea foam)... didnt do anything..

I also checked my egr, i took off the top vacum line and put a hose on it and sucked on it as hard as a could. It seems like my EGR is stuck open or closed. but could the egr cause backfiring? How hard is it to change the EGR valve?

-Robert

 

Buddy I told you it's most likely your opti-spark.

 

same thing here man... im a pull my opti out in a few weeks

but i hope it makes it that far..

 

are you sure you dont have a burnt wire or something along those lines? Could also be clogged catalytic converter, but doesnt sound as likely.

 

99.99999% sure it's your Opti. Been there...done that!

Get that bad boy outta there.

 

I am amazed at how many people here still blame every problem on the opti-spark. I would definitely try new O2 sensors at 40 bucks apiece before dumping $300+ into a new opti-spark. I have had both go out on me before and this sounds much more like an O2 sensor problem. When my O2 sensors were on there way out my car experienced the same symptoms as you describe. It started running rough at around idle while I'd be stopped at a stoplight, a few days later the sputtering progressed into the 1000-2500 rpm range and then after about a week the car was barely driveable with missing throughout the entire RPM range, probably worst at WOT. Also, you could tell the car was running way rich, smelt like pure gas coming out the exhaust. If you decide to change O2's, make sure you get AC Delco's, I tried Bosch's at first, they lasted 2 weeks before the symptons started to return. I put in the AC Delco's and its been fine for 5 months. My experience with an Opti-spark failure was a very small miss in lower RPM's for about 2 days, it did not get better or worse until on the 3rd day my car would not start at all. Thats my 2 cents, hope it helps,

Derek

 

I use OTVC wire looms so i dont burn any wires. I replaced my EGR valve today, didnt do much...

I really dont want to replace the opti spark Its not the price, but the fact this is my only mode of transportation... How long would it take to replace the optispark, my friend told me about a week to install

I might try doing the O2s, but my computer hasnt thrown on the SES light in like 2 weeks. It came on for about 5 mins then turned off. If i got it scanned what am i looking for? It wont tell me codes that were thrown, only the ones being thrown at that moment.

I dont want to just start throwing money into my car... and i was really hoping to get gears next month

 

the opti according to my thread "hours Opti?" will take u about 2 hours if u know anything about cars...

 

yea on mine, im taking from everyone in here, that its opti

but im spuddering and backfiring whenever i accelerate moderatly, WOT its fine, but idle is rough...

but i wanna get the O2's done aswell.

 

I only got intermittent codes as well with O2 sensors, the only time I would get the SES light is on long drives, after probably 20 minutes of driving when the sputtering would get really bad (feeling like the car was just gonna die) the SES light would come on and the sputtering would go away. A couple miles down the road the light would go off and it would try to read from the O2's again and the problem would come back instantly. Also, if you get it scanned it will show you codes even if they were 2 weeks ago as long as you haven't disconnected your battery since then, thats how I found out it was my O2's. Also, I would do both at the same time.

Derek

 

My WOT still hesitates most of the time... I guess its the opti

 

I had to disconnect my battery when i put my PCM back in. D'oh! I didnt know you could scan for previous codes!!

 

I think that is another myth. Everyone says that O2's do not affect WOT. That is why I discounted O2 sensors as the problem for about a week when my problems started, because my car seemed to run its worst at WOT and everyone I talked to said that O2 sensors were not used at WOT. While this may be true, there is something about O2 sensor malfunction that will still make you hesitate, sputter and misfire at WOT. My theory would be that even though the sensors are not being used when you put it to the floor, the extra gas that has been dumped into the combustion chamber because of the lean readings from the O2 sensors (which is telling the computer to add more fuel although its not needed) is still in the combustion chambers when you go WOT, so until that fuel is cleared from the chamber (which would probably take a good amount of time at WOT) you are still going to have problems. Also, if you've run your car like this for more than a week or so like I did, you may need to change plugs as several of mine became fouled because of the extremely rich condition. I would just suggest trying an 80 dollar, 30 minute fix before you unneccesarily replace your opti-spark. Hell if it doesn't work, put the old sensors back in and return the new ones and get your money back.

Derek