Mechanics

MISFIRES?

1990 Toyota Corolla

Engine Performance problem
1990 Toyota Corolla 4 cyl Front Wheel Drive Manual 80,000 miles

Hi guys,

My engine seems to misfire or knock when driven aggressively. I'm not sure but it feels like it hesitates for like half-a-second when I really floor the gas very fast. It drives perfectly when driven nicely and I can feel the pull really well, the engine had a new timing belt, new oil, new gear oil, timing was set, the distributor was cleaned and new oil seals and everything. I even changed the distributor pickup coil. Is that it? Is it the new pickup coil? And the funny thing is, I marked the previous timing of the distributor before I took it out now when I put it back, I had to advance the timing so far away from the previous mark which was I think was the best timing I had. I took the distributor out, checked it again and put it back, and still my car seems like misfires when driven aggressively. Everything's okay except that. When I drive moderately, all is okay. My friend told me to check the vacuum advance and maybe somewhere in the exhaust there's a leak.

Any ideas? Please.

Thanks a lot and more power!
Jack
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Jackolson
July 14, 2009.




1990 Toyota Corolla Misfires?

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.
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Rasmataz
Jul 14, 2009.
Thanks!

I have new Bosch spark plugs and new Wires as well, I'm using the same fuel ever since so that leaves me checking the coil, injectors, and vacuum leaks. I don't think I have an EGR valve, or my exhaust could be leaking.

Thanks. More power.
Jack

Tiny
Jackolson
Jul 15, 2009.
Only cars sold in CA. Had the EGR in the early 90's. It will tell you on the information sticker under the hood.

It will say " non EGR" or " EGR equipped".

Cars for states other than CA. Were called " Federal/Canada".

Is this a FI engine or Carb?

Mmprince4000
Jul 16, 2009.

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