i can t get my car to fire on 4th cylinder
Moderator: martauto
We need to know what type of engine you have there mate.
But as a guess, if it has fuel, spark and compression then im thinking that you have either a M10 or M20 and the N°4 exhaust rocker could have snapped. you need the rocker cover off to check for this.
To check for fuel, remove the plug after turning the engine over, it should be a bit wet with fuel at the tip.
To check for a spark, with the plug out put it back into it's lead and hold it on a good earth with insulated pliers and turn the engine over.
Never just pull a plug lead on a running engine, I used to do this as it was what i was tought but it can fry the ecu if the spark back-tracks through the wiring
But as a guess, if it has fuel, spark and compression then im thinking that you have either a M10 or M20 and the N°4 exhaust rocker could have snapped. you need the rocker cover off to check for this.
To check for fuel, remove the plug after turning the engine over, it should be a bit wet with fuel at the tip.
To check for a spark, with the plug out put it back into it's lead and hold it on a good earth with insulated pliers and turn the engine over.
Never just pull a plug lead on a running engine, I used to do this as it was what i was tought but it can fry the ecu if the spark back-tracks through the wiring
By takeing the rocker cover off and having a look?
If it is snapped then do not run the engine again untill its repaired because if the bit thats come loose gets under the cam then the cam will punch it through the head, not pretty or cheap once that happens
If it is snapped then do not run the engine again untill its repaired because if the bit thats come loose gets under the cam then the cam will punch it through the head, not pretty or cheap once that happens
Try swapping the plug to another cylinder, if the problem moves with the plug then that's the problem, It's very rare for leads to break but dizzy caps do crack.
It's a puzzler, it has fuel, compression and spark but won't fire and the valves are working as they should.
Have you tested the compression with a gauge? how did N°4 compare to the others?
It's a puzzler, it has fuel, compression and spark but won't fire and the valves are working as they should.
Have you tested the compression with a gauge? how did N°4 compare to the others?
made me think actually, a good-sparking, plug&lead when out of the head may not reveal a problem ark when in the head.It's a puzzler, it has fuel, compression and spark but won't fire and the valves are working as they should.
So yes a swap around should test..
we swoped them around it made her off a few more cyliners. Do you know the fireing order for one of these cars, the dissy cap is lik new. We have not had a compreshion tester on the car yet, but we took the spark out a one and out a four put out fingers over hole and she had equil presure obivously, we took lead from coil pack off. Could the spark sensior have anythin to do with it
It could be if the piston has given it a whack, you need to test the compression with a gauge rather than your finger, the only other way to see is to take the head off which I would not do unless I had to.
Compression testers are not that expensive and when you test it you are looking for a differance of no more than 15psi between the highest and lowest readings.
Compression testers are not that expensive and when you test it you are looking for a differance of no more than 15psi between the highest and lowest readings.
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hongkongfuey
- Mad-tango-geezer
- Posts: 3304
- Joined: Fri Jun 08, 2007 11:00 pm
- Location: portsmouth
firing order is ........ 1,5,3,6,2,4
if there wern't people like me,
with cars like mine,
who would you put down to make yourself feel better?
with cars like mine,
who would you put down to make yourself feel better?