QuestionQUESTION: Heater valve leaked out coolant and overheated engine.
Water went into old distributor with electronic ignition.
Engine will start, but will only tach at 800 rpm. and die.
Replaced with new electronic distributor and replaced ballasted coil with same results.
No oil in coolant in radiator or water in oil. Seems like an electrical problem but at a loss to find it.
Would appreciate your input before I rebuild my Weber downdraft carburetor, but don't believe that is the problem right now.
Thanks,
Scott
ANSWER: Hi Scott,
To determine if it is electrical or fuel you need to test. A simple test is to connect a timing light up and hold the trigger down and run the RPM up to the 800 RPM and watch the flash. It the flash dies before the engine stops spinning then you have an electrical problem. If not you either have a fuel problem or an engine problem. To test the engine you need to run a dry and wet compression test. If you are not familiar with the tests let me know and I will go over them with you.
To test for a fuel problem it is also simple. At 800 RPM just spray a fuel in the intake as you open the throttle. If you can rev higher by spraying a fuel into the intake then you have a fuel problem.
Howard
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QUESTION: Thank you for such a quick response.
I can keep the engine running with my foot on the gas so its not electrical. Have poured gas down carb with no results.
So back to what I fear most is a cracked head, will do a compression and air test next and let you know the results.
Scott
ANSWER: Scott, keeping your foot on the gas to keep it running does not rule out ignition. Seeing the flash of the end result of ignition rules out electrics.
Let me know about the compression test results.
Howard
---------- FOLLOW-UP ----------
QUESTION: Howard,
Timing light works, pouring gas down carb, did not increase rpm (500) but got a good back fire through the carb. Air tested #1 cylinder, no air through carb, air through exhaust pipe, but turned engine by hand until that stopped and NO air bubbles coming up through coolant (removed cap over thermostat).
Ran dry compression test (3 times each cylinder, recorded high)results:
#1) 140 psi
#2) 135 psi
#3) 127 psi
#4) 135 psi
Spec I have says low 130, high 160.
Might not be original engine, I have:18V883AEL017863
Thanks,
Scott
AnswerSince you can run at low RPM put a vacuum gauge on the intake manifold and watch the vacuum as you slowly open the throttle to see if vacuum slowly goes to zero as you slowly open the throttle. If so unbolt the CAT from the exhaust manifold so there is a gap and start the engine and see if it will run above idle.
Howard
