Multi Misfire Code trigered only above 3000 rpm's?

[tommyrockerzzz]

Hello everyone!

Hope you guys can help me out. This is a bizarre issue that I cant seem to find the answer to.

"95 Eagle Talon Tsi/awd 47K miles on motor, car run great, but when I get on the highway and proceed to 60+mph ( 3000+rpm's) the vehicle trips a code and car starts to missfire (like a plug wire jumping spark) check engine light comes on. Checked with scantool and it reads "Multi Misfire"

Here is the bizarre part, when this happens ( only happens on highway ) I can turn the engine off & on real quick and the problem is gone. I had a couple mechanics look at it, they scaned it on the highway with the problem.
Here is what they found....While scanning, 02's were fine & all other readings were fine as well, however at the moment the misfire came on, the ECM went into failsafe mode and all reading were froze. The only two things they came up with was ECM was defective or a possible short in an injector, they had metioned , due to the fact it only happens at highway speeds ONLY, its possible an injector being at high demand could be shorting out which sends the ECM into failsafe & turning the engine off & on resets the ECM. Also some else mentioned "Throttle Position Senser"??

Here are a few of the mods that matter... 9mm Wires, Plugs, Super 20G
Turbo.

Any help would be greatly appreciated!

 

[ESiJohn-95]

If it was the throttle position sensor I think that would have popped up when it was scanned. Also, if the problem doesn't surface in city driving (assuming you rev past 3000 rpm in city driving) but only on the interstate then I'd say it's not your TPS. Sorry, I can't tell you what it is, I just have a good idea what it's not.

 

[Gstclipse69]

A very common problem with 6 bolts in 2gs is the cam angle sensor which triggers a misfire code, exactly how you are describing. Now 95-96s do not have the cam angle sensor in the same location as all other models. 97-99s and 1gs have the cas on the passenger side of the valve cover on the end of the intake cam. 95-96s have a crank position sensor instead.
http://www.dsmtuners.com/forums/bol...sfires-my-95-a.html?highlight=95+crank+sensor
http://www.dsmtuners.com/forums/new...nsor-throwing-cel.html?highlight=crank+sensor
I would try a new crank sensor. Search for crank sensor and LOTS of threads will come up. How to, location, etc.

 

[ewoevo]

Mine is doing basically the same thing. The cel comes on while cruising on the interstate at aroudn 70mph, but not qhile driving around town. I'm going to swap in a coil pack to see if that fixes it.

 

[tommyrockerzzz]

I bought this vehicle with a bad turbo & I have no idea how long the previous owner drove the car that way. The car opon start-up blew lots of smoke due to the oil being pumped into the engine from the bad turbo. Now my question would be...can my "random Multi Misfire "be related to some carbon build-up in the engine? I have not atemted to clean with sea foam yet.

 

[PieEyedPiper]

Search for P0300 Random Multilple cylinder Misfire. There are tonnes of threads going on this but there isn't a clear cut solution for 7 bolt engines.
Some solved it by cleaning out their EGR, some replaced their alternator and some replace their CAS/CPS. None of those has worked for me (haven't replaced alternator or CPS yet) but I firmly believe that you can test and swap coils, plugs and wires for days and the problem won't be solved. I don't believe it is directly related to ignition, apart from the CAS/CPS.

Oh, and some did solve it with an ECU replacement as well. Feel free to post your findings and trials in this thread http://www.dsmtuners.com/forums/pro...lved-misfire-help-p0300-isc-coil-results.html

 

[clockworktoy]

Ive had the exact same problem on my old 7bolt motor. There are a few very useful threads that helped me narrow it down to my cas. In the end it was a failed crank sensor and cas that caused my miss fire. I would suggest check these two first along with your spark plugs.