Hesitation under acceleration

[bbarga]

Hello,
New guy here. I searched for answer to my question but could not find any. I have an 89 Festiva fuel injected that is low on compression on one cylinder. I believe valves because squirting oil in cylinder and retesting compression makes almost no difference. Before I sink a bunch of money in a valve job I am trying to determine if it is worth fixing. A couple months ago my ignition module went bad. I replaced it with a new one. I then noticed a miss at highway speeds that I never noticed before my first module went bad. Well the new module went bad after only about a month so I figured that was the cause of the miss. It was replaced under warranty and I still have the miss. What I noticed is that at highway speeds if I simply press the gas pedal the car will accelerate no problem. If I back off the pedal ever so slightly then press it down I get a miss. Actually it is like the ignition is dropping out because the tach will drop 300 - 500 rpm and then recover almost instantly. I know with the low compression the car is not running optimally but I can't figure out how backing off the throttle and then accelerating would make the ignition drop out. Anyone ever experience anything like this before? Do you think the second module could be bad also, as I never noticed the miss before replacing original. I figure that even if I have to put $300 - $500 into a valve job and misc stuff I sure can't replace the car for that. I appreciate any suggestions you guys have.
Thanks,
Bob

[bbarga]

No ideas??

[WmWatt]

Ignition modules can be tested for free at some auto parts stores. For more info look in www.ncf.ca/~ag384/Cars.htm .
I cleared up a low compression in #3 with chemical cleaner oil additive. Carbon buildup on exhaust valve.

[ls1_se7en]

I have a very similar issue. My car is an 89 L carburated car. I can go wide open throttle in the lower rpm range without a single problem. but once the engine get in the upper rpms (3500+ I have no tach so its an estimate), the engine will instantly lose all power and start hesitating really bad. and as soon as I back off to a certain throttle position it comes right back to life.

I have tried several timing adjustments via a light. It has new plugs (~1500miles). Someone suggested a fuel filter so I replaced that. I still have the problem.

It's possible that it could be a carb issue (for me) or a vacuum leak.

[IL4Festiva]

this is just a thought but..
when my fuel filter when bad i could put the gas down and get it going good, but if i let off and then back on, it lagged. same with revving it.