For a few weeks my car has been a little choppy at cruising speeds. Then yesterday while driving normal from a stop it would kinda stumble for a second then be fine. Later that night I was going down an entrance ramp onto the highway and it started running real rough and the SES light flashed several times. I got off at the very next exit and while sitting at the stoplight the SES light stopped flashing and it ran better, but not normal. While it was running rough I did see some smoke out the exhaust(not alot) but then it stopped. Unburned fuel maybe?

The cap/ rotor was last replaced in 2001. In the next few days I will take it to the parts store and use their code scanner, but I wanted to see what you guys thought....

Matt

 

flashing ses = P0300 multiple ramdom cylinder misfire. Check your plugs and wires first.

 

The cap and rotor being 5 years old might draw a flag. Some people have the original but others will have one go bad in a couple months.

 

Well, today I took it to the local auto parts store and used their scanner. There were no codes!! It seemed to drive ok other than pulling from one stoplight it ran a little rough.

Now I'm baffled....

 

check the plugs and wires...sounds like something is breaking down intermittently

 

Updated sig

Wires look good- I run mine over the valve covers. I'll check the plugs when it cools down. Last time I checked they were light gray/green. I run a couple gallons of 100 octane when using the N2O.

 

Yeah it's a good idea to start with the simple things first. If your SES was flashing, it was a P0300, Multiple/Random Cylinder Misfire. This code is usually associated with plugs or wires.

Even though you have them running over the valve covers, they're still exposed to some heat around the boot area. Check near the boots to see if the wires are brittle in any places. Check to make sure all the wires are installed TIGHTLY on the plugs...if so, pull each plug and inspect it. Check to see if they're tight, look for cracks in the ceramic, and look at the business end to see what's going on during combustion. You should be able to tell which cylinders aren't firing.

I just went through the same mess.

Good luck.

 

I hear you , mine just went today

 

I put NGK TR6's in it in May. I've checked them and the gap is still .035. The plug wires all looked good too. The more I drive it the more the problem seems to be in the first 5 minutes of driving, and only at part throttle.

I drove it tonight to McDonalds (I live 5 minutes away) and it ran kinda rough most of the way there and the SES light started flashing again. It flashed for about a minute, then quit and the car ran fine. When I left, it ran great.

Tomorrow or the next day I'll try to get it scanned on a good shop scanner. Now I'm wondering if it isn't a TPS or IAC...

 

I changed my coil back to stock- problem is still there. Then I unpugged my MSD 6A. Still runs rough, and it's getting worse. Sounds like the Opti to me, but I'm going to ask my Oija board just to make sure....

I've been meaning to do a cap/rotor anyway....

Do I go MSD, Accel, Summit, or parts store?

After doing more research, it looks like I need tho whole Opti...Too much neg feedback on the MSD, so I'll get a GM one from summit

 

did u take it to advanced or autozone?
i just went through this with them, they didnt tell em till afterwards. if the code is not there when u go , there scanner will not retrieve it. maybe it was just there scanner or all of the chain. but i would def take it to a mechanic shop, GL.

 

It was Checker. Good thing is they didn't charge me. Anyway, I'm going to get on on a shop scanner before I start throwing parts at it.

Wierd thing is, when it's running rough I can put the clutch in and rev the motor and it revs fine. Then it will drive ok from a minute or two,then run like crap again. The issue seems only to be at part throttle acceleration or cruising.

Matt

 

Finally got it on a scantool today. Multiple random misfire. #1 and #2 were the worst. No misfires at WOT though. Could this be because of the MSD pushing extra spark through it?

The mechanic that scanned it told me he thinks it's the optispark, since it's intermittent. I tend to agree.
Matt

 

Well, I replaced my Optispark. Man, what a PITA. I hope I never have to do that again. Anyway, there is something small rattling around in the old one. I haven't taken it apart to see what it is yet. I did get #6 and #8 plug wires switched when I first put it back together , but now it runs good....

Matt