hiphop4x4

i have swapped coils, injectors and done a compression test and it still comes back saying cylinder 4 misfire. iono what to check next. Im thinkin bout checking wiring that goes to coils or valve adjustment(never done one)...i can only feel it misfire randomly at idle but it runs fine when i give it gas...advice?

p.s. how bad would it be to drive 500+ miles with this code spittin out?

ezone

What are the results of your compression test?

What is the MAP Voltage at hot idle, in neutral or park, with no loads?

Both of the above might lead me to some sort of conclusion about the valves.....Why haven't you adjusted the valves already?
(Don't bother answering that. Just do it.)


Depends.

hiphop4x4

i had an independent shop do it and they told me...
cylinder 1- holding 80% (rings)
cylinder 2- holding 80% (rings)
cylinder 3- holding 97%
cylinder 4- holding 94%

they put rings in parentheses telling me the rings wearing out are the reason its not holding so well

iono what that is or how to check but i do have a multi meter.(?)

ive never knew of this as a routine/preventitive maintance job until reading and asking around about this misfire. if its holding good compression wouldnt that say on its own the valves are fine?

Some history for this car, ive recently(within the last month) changed head gasket, timing belt(just re-adjusted time to fix hi idling issue 2 weeks ago), waterpump, thermostat, hoses, had the head cleaned and leak checked at some hole in the wall head shop, intake manifold gasket, and valve cover seals. the original issue was blown headgasket and i just did the rest since i was going that deep into it

TYIA

ezone

Those aren't compression readings, those would be cylinder leakage readings.
This test should only come AFTER a compression test that gave poor results.

This does not explain a #4 misfire yet.

All it would indicate is that the valves can seal against some pressure (compression). Doesn't indicate much about proper adjustment.
And you don't have any results from a compression test here to evaluate anyway.

This would have been the ideal time to adjust the valves.




New question: What is the Freeze Frame data from the P0304 misfire code? Post that so I can read it..

ezone

If the check engine light is still on, go to a parts store and get the code read---AND get the freeze frame data. Printout or write it all down.

hiphop4x4

so i did a proper compression test just a dry run since the oil can i got isnt working
4 - 134
3 - 161
2 - 163
1 - 139

didnt have time for the freeze frame data today...and could i get info on gettin map voltage

ezone

If those results are truly accurate, figure out why #1 and #4 are low.

Actually, all 4 are lower than my typical results. I expect 180-220 out of these engines.

hiphop4x4

Did a leak down today...set cyl 4 tdc best I could only turning the cam, and It was losing 35% an could here obvious air blowing thru the hole on the valve cover that goes to the intake filter case...when I would plug it with my finger I would hear air flow from the #1 spark Plug hole....not covering anything i could hear a lil in the crank case and tad bit from the throttle body...radiator wasn't giving off any noise...it was low coolant tho so ima top off later do it again and see if any bubbles come out...I then did cylinder 1, set it to tdc using camshaft again. It had a 50% leak, heard no air coming from the intake vaccum line tho on the top of the valve cover but I did hear noise in the number 3&4 cylinder spark plug holes...again I heard air from crank case and tad bit from throttle body with the throttle open

I'm going to do a valve adjustment after work tonight since it'll be about 70 degrees tonight and cars been sitting for 2 days...I've never done one before but after watching some vids it doesn't look to hard

Can only learn by doing and hopefully this ****'ll fix my misfire

ezone

Yes, check and adjust valves. Gotta make sure the valves can shut completely.

hiphop4x4

i just finished up with the valve adjustment and noticed they were ALL tight as ****....i did a compression test on cylinder 4 and AMAZINGLY it went up to 180!!! couldnt believe it so i did it again and same results...didnt have time for the rest of the cylinders but ima get to em in the morning....but the 180 makes me feel good

thanks for the support ezone

hiphop4x4

I put everything back together and it's running sooooooo smooth...if anyone has similar misfire issues then valve adjustment should do the trick

fsckewe

Woaaahhh cowboy. I beg to differ!

Glad you got it sorted, nonetheless.