Engine shudder and power loss at high rpms under load -- pls Help!

**Dirtdiver** · July 4th, 2013 06:40 AM

Car is an old 1993 Honda Civic 1.5LX Sedan (non-fuel injected). Stock engine. Engine shudder/power loss occurs during high rpm conditions when accelerator pedal is fully depressed during actual driving. Doing so while car is in neutral and stopped causes no problems. Easing up on the pedal usually does the trick (but where's the fun in that?).

Was much worse before, power loss would occur in moderate rpms eventually leading to engine dying out (but restart-able after less than a minute). Had my carburetor tuned up in kamuning, QC and this mostly solved the problem except again in the conditions stated in my first paragraph.

Previous engine related work done:
Top overhaul, radiator work and various cooling hoses replaced due to excessive coolant loss leading to engine overheating.

Any ideas gurus? I really dont want to end up getting rid of the car since its been reasonably reliable naman these 20 years that my family has had it. Am actually considering restoring and modding it now that it's all mine to tinker with. TIA! :-)

DirtDiver

**1D4LV** · July 4th, 2013 08:30 AM

probably

dirty carburator or dirty fuel filter.
faulty high tension wires or spark plugs
faulty alternator
failing fuel pump.

**vinj** · July 4th, 2013 08:58 AM

My first suspect is the fuel system,. Check your fuel filter and carburator.

**jick.cejoco** · July 4th, 2013 11:57 AM

Originally Posted by Dirtdiver

Car is an old 1993 Honda Civic 1.5LX Sedan (non-fuel injected). Stock engine. Engine shudder/power loss occurs during high rpm conditions when accelerator pedal is fully depressed during actual driving. Doing so while car is in neutral and stopped causes no problems. Easing up on the pedal usually does the trick (but where's the fun in that?).

Was much worse before, power loss would occur in moderate rpms eventually leading to engine dying out (but restart-able after less than a minute). Had my carburetor tuned up in kamuning, QC and this mostly solved the problem except again in the conditions stated in my first paragraph.

Previous engine related work done:
Top overhaul, radiator work and various cooling hoses replaced due to excessive coolant loss leading to engine overheating.

Any ideas gurus? I really dont want to end up getting rid of the car since its been reasonably reliable naman these 20 years that my family has had it. Am actually considering restoring and modding it now that it's all mine to tinker with. TIA! :-)

DirtDiver

the available voltage from the ignition coil might be insufficient during transition (low vacuum and moderate rpm) or the exhaust system might be plugged up or the exhaust backpressure is excessive. try to connect a vacuum gauge to the intake manifold. get the engine idle vacuum, abrupt opening of the throttle and the sustained mid throttle engine vacuums. post your results for analysis

the ignition can be tested with HEI spark tester

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