Welcome Visitor! Please take a few seconds and - Joined
- Jun 2, 2012
- Messages
- 25,363
- Reaction score
- 8,369
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- Location
- canada
- Vehicle Year
- 1994
- Make / Model
- Ford
- Transmission
- Manual
1994 Ranger 4.0l
Driving on the freeway, had been driving for about 30 min., no warning, got a misfire, you could tell it was just one cylinder not random misfires.
No previous misfires at all.
Drove it around the rest of the day, cylinder never came back on even intermittently, just dead.
Turned out to be the spark plug, so no big deal, but the spark plugs are only year old and there was no lifter tapping, so I didn't think spark plug or lifter, I thought injector.
Pulled out all the spark plugs to see if they were the problem, as strange as it sounds they all looked fine, but #6 was bad, later test.
Since the plugs were out I thought I would do a quick compression test before pulling the upper intake to test the injectors.
Tested 1st cylinder, 160psi, then pulled it out to test the next one........then it dawned on me, check for fuel on the end of the compression tester, I didn't disable the injectors for the compression test.
Sure enough, fuel was there, cleaned it off and tested next cylinder, it had fuel as well.
When through all 6 cylinders wiping compression tester each time(155-160psi on all) and each time fuel was on the end of it, so no injector problem, well at least not enough to cause a full time miss
.
Never thought about it before but it's a "two birds" with one test kind of thing, and never seen it mentioned before.
And no, you won't wash your cylinder walls with fuel and hurt them, if that were the case then every engine that lost spark is destine to blow up, after its finally fixed, because that is ALOT more cranking with fuel and no spark than a compression test, lol.
Went back and tested each spark plug with a coil and sure enough #6 looked fine but no spark.
Put a new set of plugs in and it's back to normal.
Driving on the freeway, had been driving for about 30 min., no warning, got a misfire, you could tell it was just one cylinder not random misfires.
No previous misfires at all.
Drove it around the rest of the day, cylinder never came back on even intermittently, just dead.
Turned out to be the spark plug, so no big deal, but the spark plugs are only year old and there was no lifter tapping, so I didn't think spark plug or lifter, I thought injector.
Pulled out all the spark plugs to see if they were the problem, as strange as it sounds they all looked fine, but #6 was bad, later test.
Since the plugs were out I thought I would do a quick compression test before pulling the upper intake to test the injectors.
Tested 1st cylinder, 160psi, then pulled it out to test the next one........then it dawned on me, check for fuel on the end of the compression tester, I didn't disable the injectors for the compression test.
Sure enough, fuel was there, cleaned it off and tested next cylinder, it had fuel as well.
When through all 6 cylinders wiping compression tester each time(155-160psi on all) and each time fuel was on the end of it, so no injector problem, well at least not enough to cause a full time miss
.Never thought about it before but it's a "two birds" with one test kind of thing, and never seen it mentioned before.
And no, you won't wash your cylinder walls with fuel and hurt them, if that were the case then every engine that lost spark is destine to blow up, after its finally fixed, because that is ALOT more cranking with fuel and no spark than a compression test, lol.
Went back and tested each spark plug with a coil and sure enough #6 looked fine but no spark.
Put a new set of plugs in and it's back to normal.
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