intermittent miss throughout rpm!

[auto02]

Ok guy's,my 94 ranger has an intermittent skip at all rpm level's.The truck has about 168,000 miles and does NOT smoke at all.I did a compression test and got 90,130,105,160 in order from 1-4.oil looks fine and doesn't seem to have any oil in the radiator. The exhaust seems to have a pop to it from time to time.I checked timing and all is well.I'm guessing its a valve issue,opinions please!

 

[Moreflying]

The compression test looks familar. Although mine was not quite as bad as yours across the board. You more than likely have a few burnt exauhst valves and poor sealing compression rings. Welcome to the high mileage club. Verify the problem further with a leak down test. As far as the intermittent miss...it could be related to the low compression. Or...an ignition or fuel delivery problem. Start simple. Check the fuel pressure. It should be mid 30 psi. It will idle rough with the numbers you mentioned and there's not much you can do about that short of a rebuild or valve job.

 

[auto02]

Thanks,I'm gonna pull the head and check it out.Fuel pressure was fine.It did have one dead cyl on each coil(#1 on the driver side and #3 on the passenger side. A friend gave me a new icm that he never used so when i get the head redone or replaced i'll use it.

 

[Moreflying]

Okay. Good luck with the work. I'm in the same position. And I've had to repace my ICM before too. #3 on the front pack and #1 on the back pack was not firing. I got a check engine light with that situation though. Post up some pics when you take it apart if you can for reference.

 

[auto02]

Well,I pulled the head! It had 1 cracked exhaust valve seat and 2 leaking exhaust valves.I hope to get it back together tomorrow, just bought a reman head instead of messing with that one.I would really like to port it but I'm just ready to drive it! Also looks like someone has been in the motor already, it had a head bolt rung off in it.I'm guessing they reused the tty bolts instead of buying new ones.Once I pulled the head the bolt screwed right out!

 

[auto02]

well,got it all back together!it would crank and run great for a few minutes and just die.I then noticed for some reason the fuel pump would'nt come on sometimes.When i'd try to pull off it would start missing and sputering bad.Finally figured out it was the coils!Everything is good now!

 

[coach007]

I have a 93 ford ranger 2.3. 3 weeks ago it just started to just drop a cylinder, then go away. I hit a bump and it comes back. installed 8 new plugs--new wires--2 new coil packs. ran fine for one day and then just drops a cylinder. I pulled off #3 on front coil pack and no change in the miss...Then it just goes away only to come back an hour later . Sometimes this miss will disappear when I shut off the motor and restart. Been to Ford 2x @$95.00 and it wont fail when its there. ANY HELP ?? Thanks