ranger 2.5 misfire problems

[Errk]

hey guys I am having some issues with my rock crawler project. the engine keeps misfiring on what seems to be cylenders 1 and 4.
the truck is a 1995 with a rebuilt 2.5 swapped in. the engine has a new bottom end, the head was magnafluxed and valves where vaccume checked.
a list of the new parts...
primary coil
plugs
wires
air idle controll valve
19lbs injectors (1995 feul pump is lower pressure than the pumps on the 2.5 trucks)
feul pump
feul filter
altinator (had high voltage maby damaged computer???)
symptoms sounds like cyl1 and 4 don't Fire or fire weakly I have pulled the plug wires one by one on the primary with the secondary disconnected and 1 and 4 disconnected don't really make a change. I did a compression test 95 psi on each cylender with a 3 foot hose I did a leak down test with a compressor can not detect any valve leaks. I cleaned maf, swaped injectors around etc. plugs 1 and4 have some feul on them but they defenatly apear to be sparking.
I put new lifters in thinking they may not be letting the valves close 100% with oil pressure, this seemed to almost fix the problem for about a day with only random slight misfiring but the symptoms came back. I would love some other thoughts on what could be going on, I really want to run this engine but if I can't figure this out unfortunately I'm going to have swap a different engine in the truck!

 

[mypaperpast]

maybe try a new MAF all together...the misfire on my truck went away after i put a new one in however mine was also throwing a maf trouble code...don't know if that helps......

 

[tomw]

A 95 on a compression test would be a FAIL in my grade book. A repeat test with the throttle plate wide open and the engine warmed up may give a different result, and if not, then someone sold you something you did not get.
I would ignore the drivers side plugs as they aren't used to 'run' the engine, but for emissions reasons, and will not affect driveability.
Given you have a problem with a pair, I would be concerned about the ignition parts. If this is a 'waste spark' system, both plugs fire once per rotation of the crankshaft. ONe fires to ignite the fuel/air mix. The other fires because it is connected to the same coil.
I would try swapping coils as a first least expensive step. Then you swap plugs, wires, etc to see if the misfire follows the parts.
Have you access to a timing light where you could watch the ignition fire the plugs to verify they are being sparked?
tom

 

[enjr44]

95 psi on all cylinders means (to me) you did it wrong or the gauge is bad. I agree with above that you have some sort of ignition problem.

 

[Errk]

Thanks for the input guys. I ended up finding the problem today I pulled off the header and did a leak down test... The exhaust vales are leaking big time especially in cylinder 4. I gess the machine shop Did not actually check the valves. Oh well only took 60 min to pull the head. Btw I think the compression checker is inaccurate because it has a 3 foot hose. Now I am in the search for a 1989-1994 cam for a little extra lift to go with the head work anyone got one?

 

[tomw]

'89-'94 Ranger Roller cam .215" lift at lobe. Lobe is .675 wide
Follower's roller diameter is .900"

'95-'01 Ranger Roller cam .215" lift at lobe. Lobe is .510 wide
Follower's roller diameter is .900"

Cut and pasted from the sticky at the top of this forum.
Here:

http://www.therangerstation.com/forums/showthread.php?t=9

Far as I can tell, the lift is the same. Did I miss something?

I'll trade my flat followers & cam for your rollers... Just send me the parts, and I'll send mine back in the same box. HA!
tom
tom

 

[Errk]

I realized that after some more research. I came across the Route 66 hot rod website with a lot of bad information... the cams seem to be exactly the same just different followers