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Odd misfire?

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subliminal1284

Probationary Member
2
0
Apr 28, 2011
Kenosha, Wisconsin
First off I know nothing about DSM's I am an F-Body guy but I recently acquired a 97 Eclipse Spyder GS-T. The problem it is having is it stutters when getting on the throttle and doesnt want to accelerate, if I let off the throttle and back ease into the throttle and drive normally it runs perfect the idle is very smooth. The check engine light did come on and is giving a code P0300 multi cylinder misfire. I checked for vacum leaks and found none as far as I could tell, I pulled the spark plugs and they looked decent, The spark plug wires look new. The car is stock and is not modified in any way. Any places in particular I should start looking? Thanks in advance.
 
Boost leaks, TPS adjustment.

Check out vfaq.com, it has alot of good reads in it.
 
I didnt check the gap, I noticed on the valve cover near the spark plug holes there are arrows pointing in different directions, what are those for?
 
If its a multiple cylinder misfire and you have checked the plugs, wires, coils, and all those are good, then I'd say next step is the power transistor (Ignition control module). I had a multiple cylinder misfire in 1 & 4 and that was my issue after throwing almost $500 at it it was a $100 fix brand new. My car ran great after this.
 
Hey my friend I have a 99GST Spyder and I have replaced coil packs Coper NGK 0.28 gap plugs, MSD Wires 8.5mm, new injectors, cam sensor, crank sensor, I cant stop getting over and over cylinder 1 Misfire, and Cylinder 4 misfire, and random misfire codes never cyliner 2 or 3. Check Engine. what do you think it is man I'm stumped.
 
Check for oil residue or any dampness from the boot on the plug wires down to the plug. Sometimes residue can cause the electricity to arc from the wire to the head (yes through the insulation) I had this problem and was stumped. Sometimes if this is happening you can see small things on the wire that look like pinholes where it has arced. I pulled my wires, Cleaned the holes with brake clean (with the old plugs still in, changed my plugs and put better wires in and was good to go.

My symptom was every time I would start to hit boost and or gas it a bit. It would stutter and have a very hard time moving itself.

My valve cover gasket was the 2 piece btw. Was leaking a bit and let the bit of oil in on the cam side.
 
+1 for the tps. Also if the car is running rich it could possibly be due to a bad MAS. you can un hook the wire going to the MAS and if it will the accelerate normall ( while running super rich and like garbage) then its the MAS.
 
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