3 Dead Cylinders

[e-ranger]

I've got a '90 XLT with a 4.0L and an automatic.

I recently replaced the head gaskets, push rods and rocker arms and installed a set of Hedman headers and y-pipe. This is not my first rodeo as I've rebuilt many engines (mostly V8 carbed motors.) Everything is torqued correctly and installed properly, I've triple checked all the torque specs.

Upon start up, there are no mechanical noises. I checked valve operation prior to start up and everything moves correctly. I checked fuel pressure at start up and it is around 38-40 psi. All the injectors are working (I can hear them tick with a stethoscope.) The fuel pressure regulator seems to work properly ( I can pull the diaphragm back and forth by sucking on the vacuum line.) I replaced the coil pack because it was 2k ohms out of spec. The wires and plugs are new and gapped correctly (.044 in.) The motor ran correctly before all the work was done, however it did consume lots of coolant (thus the work being done.)

Originally the motor would start, but missed on 3-4-6. Now it does not start at all however, the spark plugs do spark . I checked cylinder pressure and all cylinders hold good pressure ( 120 +/- 5.) I do not know where to go with this. Suggestions?

Erik

 

[e-ranger]

bump

 

[Earl43P]

Timing?

Could it simply be 180* out?

 

[MAKG]

Those cylinders correspond rather suspiciously to injector bank #2. Are you ABSOLUTELY SURE all the injectors are firing?

 

[Bob Ayers]

Timing?

Could it simply be 180* out?

With DIS, and EDIS they plugs fire every revolution of the crank, so it can't be 180* out........

 

[e-ranger]

Well, I'm making a huge guess here. I removed my fuel pressure gauge today and it hissed at me before slinging fuel everywhere. I know there is 40lbs of pressure in the line but I think some of it may be air pressure. I bled the system ,so to speak, then restarted it. It runs better, cylinder 3 and 4 seem to be miss firing, but not up to par, obviously. I believe that the fuel filter may be clogged. I'm going to replace it soon and hopefully this will solve the problem. Thanks.

Erik

 

[MAKG]

Air in the fuel rail will be worked out quickly. It's not a hydraulic system. The "fluid" is consumed, and it recirculates.

 

[Bob Ayers]

Air in the fuel rail will be worked out quickly. It's not a hydraulic system. The "fluid" is consumed, and it recirculates.

From about 1999 and later, the fuel system is "returnless", the fuel doesn't recirculate.

 

[MAKG]

From about 1999 and later, the fuel system is "returnless", the fuel doesn't recirculate.

The vehicle at hand is a 1990, and returnless merely means a minute or two of waiting before the air is pushed out the injectors.

 

[rickcdewitt]

I checked cylinder pressure and all cylinders hold good pressure ( 120 +/- 5.) I do not know where to go with this. Suggestions?

Erik

anyone else notice this?120 all around is hardly worth putting new cylinder heads on.a good cylinder should have 150-170psi

 

[mikey67156]

Late to the party

I have exactly this same issue on my '92. Was it ever resolved?

I am getting good spark, and all my injectors are Ohms checking good. I can get it running after about 15 minutes of constantly babying the throttle. When it does finally get going the idle smooths out quite a bit, but I can pull off the #4, 5, and 6 plug wire and the idle doesn't change a bit. The EDIS, plugs, and wires are new.

Checked fuel injector wiring from EEC to injectors (white wire @ pin 59) and it shows 1 OHM resistance from EEC to #4, 5, and6,s white wire. The red wire on each shows 14.4v. Same as the right bank which is working fine.

Anybody know how to check the white wire from the EEC to see if it is doing what it is supposed to be doing?

 

[e-ranger]

I retraced my plug wires and found that I had crossed a few. It took a fresh pair of eyes to discover it and I thanked my buddy after slapping myself in the forehead. My suggestion is to pull off all your plug wires and route them over the intake to each plug, one at a time, to make sure that they're where they're supposed to be. I had two crossed and the timing was such that the other one fired, just extremely retarded or advanced. This was about 6 months ago I think so I don't remember the numbers, but I believe cylinder 2 was involved.

It's a simple and easy mistake to make, but that's where the best of us get busted, on the dumbest of things. Good luck.

Erik

 

[naford]

Ouccchhh! Good deal thanks for coming back to tell us that it is fixed and what fixed it.

 

[mikey67156]

That's what I was hoping for, but unfortunately mine are correct. Going CW I have 1,2,3,4,6,5.

I'm leaning toward swapping the EEC Monday morning.