Engine coughing under load

[90fomoco]

I have a 90 EFI that just started having engine trouble. The car starts and idles fine. Under load the engine coughs severely. If i keep rpms above 3000 it does not appear, but when you shift to the next higher gear and rpms drop, it coughs and sputters and slowly starts to die. If i push the clutch in and rev it, everything sounds fine. The only work I have done on it in the last couple months was to replace the plugs about 1 month ago. There were no problems until this morning. I have read other comments about the fuel lines and MAF sensor, or even failing spark plugs and wires. Not sure though, if in first gear when it happens, the car bucks so bad you almost hit your face on the steering wheel! Any ideas??

[Flyin4stroke]

Just needs a tune up. Wires, Distributor cap, rotor button, fuel filter. You will be in there like swimwear.

[90fomoco]

Plugs have only 1000 miles on them. Could a dirty fuel filter cause the engine to buck and cough?

[bravekozak]

Certainly.
Too dangerous to have mechanical fuel pressure gage inside the passenger compartment. That would give a lot of answers.

[FestYboy]

if it's happening under high load, low speed conditions, suspect the ignition system (particularly the wires and coil).

dirty fuel filter would act just the opposite (high load high speed condition).

[90fomoco]

Does this sound like a pre-ignition problem? Since the stutter seems so violent?

[Icababe]

I had something similar a while back. Turned out to be air flow. The choke and throttle body were filthy.

[90fomoco]

Problem solved. 2 problems actually. There is a small coolant hose that has a preformed elbow that sits right in front of the distributor that had a pin hole in it. It was spraying coolant on the distributor and wiring. Replaced that but still running bad. Waited until it was dark outside and then started it up. The cap and wires were arcing to each other in about 6 different spots. Replaced the cap and a new wire set and she runs like a dream!!!!!!!

[FestYboy]

hmmm looks like ignition strikes again (pardon the pun and mild gloat), i've seen that symptom all too often and it's always the same thing: contamination that leads to spark leak.