1991 q45a engine skip at idle

[BHurvitz]

Hi, my 1991 q45a engine skips at idle. The car has 120,000 miles. The skip comes and goes. The car runs OK, just skips at idle. My fuel pump makes noise, could it be that? Plugs have 60,000 on them, may be plugs. The fact that the skip comes and goes leaves me uncertain of what the problem could be. I use cheap 93 octane gas, but add Lucas gas treatment. Seems to be worse in damp weather. Any ideas?RegardsBob

[PalmerWMD]

Anytime the fuel pump makes noise it <must> be replaced whether its your problem or not ( even tho it quite possibly is).

if you let it go too long it <will> take out the ( much more expensive) trimode fuel pump controller.

Fred...

[DAEDALUS]

LOL "Cheap 93 octane gas"? Oh, to have it so good. In CA 91 is the best we can get commercially. It could be injector, coil, or plugs. I don't think it's the pump since it comes and goes, but Fred's right of course; it should be replaced based on symptoms alone. Controller costs more than the pump.Since you need to replace the plugs anyway, do that first. The way they look may tell you which cylinder is the bad one and what the problem is.

[wlong]

I had an occasional idle skip at 90K although my fuel pump was making very little noise. I replaced it and the idle problems went away. Apparently the pumps can get weak without the classic buzzing noise.

I recommend that you replace the pump (easy job) and run some BG-44K through the engine to clean things up. If the problem persists, start looking in other areas like MAF, coils, plugs.

W. Long

[VA99Q45]

I had exact symptom with my Q, but without the pump noise. I replaced the plugs, adjusted idle screw, switched to different gas station but there problem still there. I finally used BG44k, and it fixed the idle problem for me.

[texasoil]

lots of plugged injectors from cheap gas. Good clean fuel is essential to long trouble free life. Cheap fuel and oil leads inevitably to mega expensive repairs and parts replacements. Preventive maintenance guys.