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Twilight Fenrir

'86 Pontiac Fiero engine help needed...

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I've got an '86 Pontiac Fiero with a 2.5L 4cyl 5spd that has been just a nightmare for the last month and a half... I cannot figure out what is wrong with it... Might want to grab some snacks, this may be a long post...

Initially, my ignition system crapped out. I was pulling into my garage, and there's a slight incline going in, well, I didn't have the throttle pressed enough, and stalled. Car wouldn't start again. Replaced my ICM, and the car ran hunky dory for about a week, before refusing to start again. A bunch of stuff happened between, but eventually I replaced my entire distributor, ignition coil, plugs, and wires. I set the timing, and my ignition system has been perfect since.

But, sadly, it did not give me a running car. It starts, and idles smooth as it ever has every time I crank the key now. For a while there, I could hop in, start going down the road and it would accelerate fine through first, second, and third gear... then it would just stop going any faster when I hit 4th gear. I could never get my speed above 55. On my return trip from one of these little outings, I noticed my exhaust manifold was glowing a dull red... That ain't right...

But whatever is wrong seems to be getting worse. My little outings always started out accelerating smoothly, now I'm getting a lot of misses unless I press the throttle hard. (Though, it might just be the hole I opened in the bottom of my converter to see if my exhaust system was blocked making more audible what I didn't notice before)

While idling, if I lightly nudge the throttle, it starts to sputter, and will eventually die unless I a) release throttle back to idle or B) push the throttle more.

So, I've checked my fuel pressure, it's at 13 which is exactly spec for my TBI vehicle. And replaced my fuel filter. I've run a compression test on all 4 cylinders, all of which are in excess of 130psi (not bad for nearly 200K miles) My sparkplugs are a healthy tan-ish color. At idle, my vacuum gauge shows 20. When I nudge the throttle, it drops to 13.

Please, can anyone tell me what the heck is wrong with my car? T.T My diesel truck is eating me out of house and home to keep fueled to go back and forth to work every day. And the low gas prices are laughing at my loss of my 40mpg Fiero T.T

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Your timing might be retarded. When you set or check the timing you have to disable the computerized advance. Check the factory manual. You have to ground or unplug a wire somewhere to do this. The advance might not be working or the balancer may be shifted and the marks aren't accurate. With a timing light on you should see a difference as you go from idle to high speed. With the advance disabled timing won't move much from idle to high speed.

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Your timing might be retarded. When you set or check the timing you have to disable the computerized advance. Check the factory manual. You have to ground or unplug a wire somewhere to do this. The advance might not be working or the balancer may be shifted and the marks aren't accurate. With a timing light on you should see a difference as you go from idle to high speed. With the advance disabled timing won't move much from idle to high speed.

...... oh for god's sake..... XD I'll bet you that's exactly what's wrong... damnit... I'll go try that right now... If that does it, I'm putting you in for a Nobel prize...

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Yep... that did it... Now I feel like an idiot XD But, I'm so happy to have a running car again, it's not bugging me how much money I wasted on such a simple thing :P

Actually had to get AWAY from the specialists... kept getting wild suggestions based on the peculiarities of the car, rather than common idiocy of the technician.

Thanks a lot!

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Glad I could help! The red exhaust manifold nailed it. Fuel was still burning after it left the cylinder. A long ride could have been a disaster.

Edited by misterc9 (see edit history)

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