Cummins 4BT & Diesel Conversions Forums banner

Engine miss.

35258 Views 141 Replies 26 Participants Last post by  nexxussian
Injectors are good, and have been pressure checked.
Valves adjusted
Compression test good, all 4 around 400

I still have a miss. Low power, poor fuel economy. If I keep the idle around 760 when i put it in gear it LOPES.

What else to check?
1 - 20 of 142 Posts
Ve, rotary

If i crack any injector lines while running, it runs worse...
this is obviously a IP issue.
Ther was a guy,who listed his problems on a trip with his VE,and it turned out,there were some broken/worn parts in the Injector pump.....may be what's wrong with yours....
Head gasket......
Crap.


Looks like after all the head gasket between 2/3 is bad....

Oh well.. Here I go...
Cheaper than a pump tho...get out the elbow grease and your clicker:) Just went thru this for a wristpin bushing.
Thought a compression test would failed with this condition
Seems like a compression check would've shown those two cylinders lower than the others....how did you confirm it was blown?
Seems like a compression check would've shown those two cylinders lower than the others....how did you confirm it was blown?
It ended up being 420,360,340,400...

The head has some weird raised areas in the piston area.
ahhh, okay. most things I've seen say within like 10% of each other I think....so that would just marginally fail. Any pics of the raised areas?
No pics. Semi circular raised 'indentions' about the radius of the piston, but offset in the bore where it would be impossible to be a piston that runs into the valve seats on cyl 3. Same patter between 2/3.

Head guy has been doing it 25 years and said he has maybe seen it once before. No idea on cause.
Bent exhaust valve in #3. .005 removed to straighten it up....
Bent exhaust valve in #3. .005 removed to straighten it up....
Still misses.......
May still be an injector pump issue
I have one he'll of a leaking injector. I think my return line is leaking. I wonder if a return line leak would miss?
The return side is low pressure ! The only time you can have a miss is on high pressure side lift pump to I/P ,I/P to injector or air in the system,bad injector,or injuction pump . If your injector is leaking than yes you can have a miss only if it's on the pressure side !

Scott
im going to post a video.... it leaks THAT bad.
Injector pump check out fine.....

Still misses........
1 - 20 of 142 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top