Troubleshoot hesitation

[Walt]

1998 Esteem 1.6l

For a while my Esteem had some low RPM minor hesitation. I lived with that. Last weekend I went to the mountains twice (120 miles each way). On my first trip back the car developed a severe hesitation hicup under moderate and heavy throtle. I did get a CEL code 301 which is misfire cyl 1. I cleaned my EGR and PCV and it seemed to cure the low end minor hesitation but not the severe under load hesitation-hicup. Before I went back to the mountains I changed the plugs and the car ran great. I thought the problem was solved. The car ran great all the way to the mountains (120 mi) and 1/2 the way back. On the way back the major hesitation returned.When I say major I mean major, I would call my last 10 miles to home nursing it. However, the next day and since then it has ran great. If the car were carburated I would say it was a vapor lock because on the long trip the engine compartment gets hotter than short trips. But since it is EFI that should not matter. Any ideas anyone?

Walt

[Isuzuzuki man]

I forget if the 1.6 has coil on plug or a dist, either way, you either have an injector going bad, or the spark on 1 going out.

[Walt]

the 1.6l has two coil packs each handleing two cylinders. Would an injector or a coil pack be intermitten like described? I wonder if it could be a fuel filter.

Walt

[Isuzuzuki man]

Originally Posted by Walt

the 1.6l has two coil packs each handleing two cylinders. Would an injector or a coil pack be intermitten like described? I wonder if it could be a fuel filter.

Walt

Yes they could and I would think a fuel filter would affect all cylinders. If it has a replaceable filter, then do it, eliminate the possibility.
This coil pack setup (waste fire system) would probably affect two cylinders.