1994 ford ranger 4.0 OHV

[Felzart]

Hello I haven't seen a post with issues I'm having. My ranger just got out of the mechanic for diagnostics and the passenger bank isn't firing at all. It used to run great and has been down for almost a year. It has spark and fuel. A compression test and fluid compression test was done and the discrepancy between worst and best cylinder was 50psi. Im trying to figure out what the issue is as to why my engine won't run. It has new spark plugs, wires, fuel pump, the IAC works and so does the MAF. No vacuum leaks according to the mechanic shop.

 

[gaz]

@Felzart
How exactly have you determined that you have adequate spark and fuel?

 

[Felzart]

@Felzart
How exactly have you determined that you have adequate spark and fuel?

I pulled the plugs and shocked myself. I have new injectors that I confirmed spray in an even cone

 

[SenorNoob]

93 3.0? 4.0? Either way I'm gonna suggest checking signal with a noid light. Doesn't matter how good the injectors are if they don't have power and a ground signal form the computer.

 

[Mechrick]

Your firing order is 142536. The cylinders are 1-2-3 on the right bank and 4-5-6 on the left bank. The injectors are bank-fired, 1-2-3 fire at the same time, and 4-5-6 fire at the same time, as long as it's not a California emissions vehicle, in which case it's SEFI. But I doubt that from your symptom.

Make sure the red wires going to the injectors on both banks have 12v with the key on.

When running, the tan wires (pass bank) and white wires (driver's bank) should momentarily ground with the injector pulse. This can be seen with a noid light or LED test light.

 

[gaz]

@Felzart
Have you performed the 50/50 test. Try starting your engine with starting fluid:
• if it starts you have a fuel issue
• if it doesn't start you have an ignition issue.

 

[rumblecloud]

Welcome to TRS.

And thank you for your service.
(from another 94 4.0)

 

[Felzart]

@Felzart
Have you performed the 50/50 test. Try starting your engine with starting fluid:
• if it starts you have a fuel issue
• if it doesn't start you have an ignition issue.

The truck will start but won't go above 1200 rpms. The IAC is fine that's already been checked, cleaned, and replaced

 

[Felzart]

93 3.0? 4.0? Either way I'm gonna suggest checking signal with a noid light. Doesn't matter how good the injectors are if they don't have power and a ground signal form the computer.

It is the 4.0 ohv

 

[SenorNoob]

If it runs on one bank, I can't see there can be anything wrong with the spark. AFAIK these have 3 coils controlled by the computer that fires one plug on each bank at the same time. The power actually leaves the coil, to one spark plug, through the engine block, thru the other spark plug, and back to the coil. That's why factory calls for 2 different spark plugs depending on which bank. One side needs a platinum tip and the other needs a platinum electrode. Or just use double platinum all around.

 

[Felzart]

If it runs on one bank, I can't see there can be anything wrong with the spark. AFAIK these have 3 coils controlled by the computer that fires one plug on each bank at the same time. The power actually leaves the coil, to one spark plug, through the engine block, thru the other spark plug, and back to the coil. That's why factory calls for 2 different spark plugs depending on which bank. One side needs a platinum tip and the other needs a platinum electrode. Or just use double platinum all around.

So I did replace the spark plugs all at the same times and the spark wires. I'd think I have the right kind the entire way around the block so I dont think my spark plugs would be the issue as to why one side isn't firing. Any chance it could be an issue of frozen valves so air isn't getting in or exhaust isn't getting out?

 

[gaz]

@Felzart
To verify that your valves are moving, remove the suspected bank's valve cover and rotate the crankshaft by hand to verify their movement.

I would inspect the wire harness to the bank that isn't firing.

For the sake of discussion, is this the EGR or non-EGR version?

 

[Felzart]

@Felzart
To verify that your valves are moving, remove the suspected bank's valve cover and rotate the crankshaft by hand to verify their movement.

I would inspect the wire harness to the bank that isn't firing.

For the sake of discussion, is this the EGR or non-EGR version?

How do I figure out if it's the EGR version?

 

[gaz]

@Felzart
• It will have 3 wires to each injector, instead of 2.
CORRECTION: it will still be only 2 wires as in Federal (non-EGR, it will be 2 colors wire per bank; for California (EGR) it will use a different color wire for each injector plus the common, a Red).
• On the driver's side, there will be hard tubing connecting the exhaust manifold to the EGR valve on the upper intake manifold.
• the placard under the hood, near the hood latch mechanism may state California Emissions, verses Federal

 

[Felzart]

So I called the shop to get the compression numbers and this is what I got
Compression dry/wet
1: 185/190
2: 135/130
3: 170/180
4: 175/180
5: 180/210
6: 175/200