4g61t.org

Ok, so I tried to search as many different terms as I could think of to find a problem like what I'm experiencing. I didnt bring up anything that really helped.

CAR: 89 Eagle Summit, 4G61 NA, 137k miles
ISSUE: Misfire at idle, while accelerating, and surging while holding a given RPM. Also, a couple days ago, the car couldn't top 65mph, and as of today, it can't do better than about 54mph. so its getting progressively worse. With the MAF unplugged, it idles better but doesn't rid itself of the miss entirely, and with revs it misses about the same. The surges while driving feel as though the tank is almost empty and its just not getting enough fuel all at once. Idk what the problem is. I need to comp check the cylinders as when I got the car cyl 4 was way low at around 75psi, and may have finally given up the ghost. I checked for spark on each wire and according to the checker, they are all firing. I need to pull the plugs and see what they say.
The problem arose shortly after making a 60 mile round trip to see my mother and family. I got home, parked the car, went in. When I came out the next day to go to work, the car started but then had the miss. I hadn't noticed it previously. This was probably 3 weeks ago. At that point it was only a minor thing and was barely noticeable. Now the car can barely move itself.

Please help. I need this car, I love this car. I was really hoping to get her to last long enough to tag it as an antique ( can't wait for that day!) but there is no way in her current condition unless I park it in a garage now and don't touch it for the next few years (agony).

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If you can't burn it down, blow it up!
89 Summit 4G61 N/A<<<all the turbo goodies without the turbo

Check your:


Your spark plug wires for spark "arc"

Your spark plugs [check for oil on them]

ECU for leaking caps

When's the last time you changed your fuel filter

Last but not least, get a compression test done.

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Geoff
2013 Genesis 5.0 RSPEC
88 Mazda Turbo II- LSX7
89 2.0 Turbo Colt
13 Ducati 1199 Panigale

I havent ever changed the fuel filter. When I got the car it had only run for a couple weeks before it was parked and not touched for years. I was thinking fuel filter needed changed...but I feel like and idiot because I don't know where it's located.

EDIT: When driving, the car will achieve maybe 3000 RPM in 4th or 5th then no matter how hard you press the accelerator pedal, the rpms either don't change or may rise at an extremely slow rate (100 rpm in about 2 minutes). The less you press the pedal to accelerate, the smoother the acceleration.

_________________
If you can't burn it down, blow it up!
89 Summit 4G61 N/A<<<all the turbo goodies without the turbo

Like Geoff mentioned, pull the ecu and open up the case and check the caps for leaks. Is there a check engine light on?

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93 Mitsubishi Expo LRV 1.8/manual
95 Eagle Summit DL Coupe 1.5/manual
01 Mitsubishi Mirage ES Sedan 1.8/manual

No CEL. I went and got a fuel filter. Will replace it either today or tomorrow. IF that doesn't fix the problem, then we move on in troubleshooting, because the fuel filter was due for a change anyway.

_________________
If you can't burn it down, blow it up!
89 Summit 4G61 N/A<<<all the turbo goodies without the turbo

Do a compression check and let us know the results.

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Had a:
1991 Eagle Summit ES Hatchback - 4g15 12v 5spd
1991 Dodge Colt -4g15 12v 4spd
Have a:
1978 Oldsmobile Cutlass - 468BBO TH350
Round 3:
1990 Dodge Colt-4G63T 5spd

OK so replaced the fuel filter. the old one was full of crap. it was a thicker than fuel brown gunk probably mainly rust from when the car sat for years. I cleaned the tank but never did clean the rest of the fuel system. The car runs a lot better but still isn't back to 100%. It tries to not misfire when idling. It will go along then you will hear it miss then go for a bit then miss. It still misses under acceleration, but not as badly. Perhaps there is contamination that got past the fuel filter or something that needs to work its way out. I can feel the injectors pulsing at idle, so they seem to be working. I would have done the comp check while I had the fuel pump disconnected but I could not find the comp check gauge.

_________________
If you can't burn it down, blow it up!
89 Summit 4G61 N/A<<<all the turbo goodies without the turbo