Strange Misfire problem please help

[pjules]

Guys I have a 98 GSt with 6bolt Swap. Rescently I have been getting the misfire code. I noticed that when i reset my ECU with the scan tool my car runs ok. What have been happening is when I boost up to 4k rpm my engine sounds like it is running on 2 cylinders, then I would get off the throttle and let the rpm drop to 900 and get on the throttle again and it will run smooth til I hit the 4k mark under boost. When I check the code, it gives me the misfire code. Then I would do an ecu reset or clear the codes and the car would run fine again until it set the misfire code and same problem occurs. Also I have my emission system including mdp sensor disconnected so I am getting the emission codes also.

 

[JayRolla]

Isnt this a problem with swapping a 6 bolt to a 7bolt car. I read somewhere that DSMlink gets rid of this random missfire problem.

 

[cristikal1783]

What cam angle sensor do you have on your car. You need to get the black top cas off a 94 talon/eclipse.

 

[Spyder4g64]

Just for the record, yes it is a problem with the 6bolt in a 2g swap. You need to invert the cam angle, and wire the injectors to fire in the right order. Very simple to do, and is found here... roadraceengineering.com

 

[Jetblack]

Even after that you'll still get a random misfire code that dsmlink can cure.

 

[wazzelby]

The misfire code will continue to haunt you unless you disable it. As stated above, DSM Link has this option. Which CAS are you using? I think the blacktop is the easiest for the swap. I'm using the green top and DSM Link and have never gotten the error. Either way you need to reverse your spark plug firing order (you can do this by swaping the plug wires). As stated above you can find great details on this at the RRE site.

 

[pjules]

You guys are great It is the random misfire issue I am having. I swapped my cam sensor with another green one, and I get the code about every 10miles now rather than every mile with the other. I will be looking for a black top version and hope that it will solve the issue. DSM I had one, but dont like the fact that when I lose battery power my settings are gone.

 

[BISHILVR]

I think that keydiver can add this to the code on his chips also.

 

[gsxitement]

I'm having a similar problem. The car drives fine (although cold start sucks), but if I hold my revs at steady cruise I.E. driving to my girlfriends house on the highway, at right around 3K, the car drops a cylinder (#3 according to my scanner at work). If I step on the clutch, or even lift off throttle a little (mostly have to step on the clutch), the cylinder comes back until i resume steady cruise. I have a fully built 6 bolt in a 98 car. I was reading some other threads and they said the whole rewiring of the injectors or swapping the plug wires is on the 95-96. I have the green top cas with the four wire plug. I need some definitive answers on this because my car never did this until I rebuilt the motor. I 've had the 6 bolt in my car for some time now. I had to rebuild the bottom after it blew after the dyno, but thats another story. I have a new ignition module, NGK 8's, NGK wires (soon to be magnecore 10mm's). any help would be greatly appreciated as my girlfriend thinks I'm crazy for going through so much insanity for a car. But she doesn't understand the DSM addiction we all have here. thanks.
Jesse

 

[pjules]

Ok I got it it is the random misfire! Everytime this happens, I would clear the ECU with a scanner and the car will drive good for 20miles or so and then it would re occur. I am currently looking for the black top CAS as I am using the green one. I know there is the resistor mod to fix it , but many has said it is a bandaid fix. Guys thanks a bunch.

 

[gsxitement]

just out of curiosity PJ, What are you doing with your MAP sensor? Do you have it hooked up, unplugged or just hanging?

 

[silvawolfe]

Iv'e got the same problem but it just started one day on the highway. Only difference is as long as I'm accelerating it will not stutter but once I am no longer boosting it will start up again.
I already swaped out the coils, PTU, and injectors since I had extras. I have a swapped 2g with all the proper wiring mods per RRE and I've put 20k miles on it with no problems until now. Thanks