Ok now I'm total confussed. I just went to retest and the needle is rock solid at 39 lbs, and only drops to 36 lbs when I race the motor. The only thing different is a stopped the very small leak fromt the tester hose but it was only leaking a couple of drops. I just test drove it and it's still acting up. So now I'm back to thing the fuel pump is ok.

 

I think 39 psi is a little too high. My experience is that the fuel pressure regulator at the inlet to the rail drops the 40 or so from the pump to about 31-32 psi. The regulator needs engine vacuum to operate. Have you checked for vacuum leaks? One thing that gets overlooked is the EGR valve. If its bad, the EGR valve's vacuum diaphragm is often ruptured, which will allow exhaust to flow into the vacuum system. This can cause all sorts of odd problems. If this is indeed the case, the hot exhaust gas can melt the plastic body of the EGR valve and blow a pinhole in it. The good news is that the fuel pump does appear to be OK.

 

Ok, I finally broke down and took the truck to the shop. My mechanic tried an ignition coil he had on hand and that didn't help. He said the EGR checked ok. He said he unplugged the map sensor and it ran good. He told me he started messing with the pick-up coil(cam sensor) under the distributor cap. He went for a test drive and the truck was started working. He didn't charge me anything because he said he didn't really fix anything. The truck ran perfect for about 15 miles and then i started acting up two miles from the house, but not near as much as before.

I talked to my mechanic and he suggested that I replace the pick-up coil assembly. So I replace it tonight and it ran good for about two miles. Then it really started acting up again.

My Mechanic says there is no way the timing belt slipped. Before I took the truck to the shop it seemed like like 3 gear was the issue at 1600 to 2000 RPM's and now it seems like 2000 to 2400 is the ugly spot it acts up.

To summarize what has checked out so far:
New plugs gapped at .35
New plug wires
New distributor
New rotar cap
New pick-up assembly
Compression 125 lbs +/- 5 lbs in all cylinders
Fuel pressure 39 lbs
Ignition coil ok
New EGR
Map Sensor ok
Fuel injector's all 14.8 or 14.9 omhs

Anyone have anymore idea's?

Thanks again everyone for your input!

 

If you can find a known-good PCM, switch it out. If the problem goes away, you have the culprit.

 

Ok Rambler I just installed a new(used) PCM. I drove it to town and it ran great first the 3 miles then are hell broke lose. So I took it to O'Rielys and got one error code....32 EGR Solenoid circuit. Could the EGR be the problem with the way I desricbe my problems? God I hope this is the end to my problems.

 

One thing no one has mentioned is the catalytic converter. If it's plugged, it could very well set an EGR code. A quick way to check is to use an infrared thermometer to measure the temperature at the inlet and outlet of the cat. If the outlet is signifigantly colder than the inlet, the cat may be plugged.

 

How is that? Is it that there is too much backpressure, which is getting picked up at the EGR backpressure transducer, and setting the code?

 

Exactly. I had an Exploder at the shop the other day that blew a nickel-size hole in the EGR from a plugged cat. It set EGR codes, but never a P0420 or any other cat code.

 

My fuel pump went bad in my 1995 Dakota and the cause was not obvious. I had stumbling at high speeds and once the engine warmed up. After replacing enough items, such as you have, it started to become obvious that it had to be the fuel pump.


Your fuel pump is 10 years old, I see no particular reason why it has to be perfect. I think there are more reasons why it should not be good. I was unable to measure fuel pump pressure under load, just at idle and increasing RPM's in the driveway. I believe that if you could measure pressure, or volume, under load, the load of an acceleration for example, you would see that the volume of gasoline delivered by the pump is insufficient.


From the helpful guys here on this site, I found the best way for me was to remove the truck bed to gain access to the pump. There are about four or six bolts, tail light cables to disconnect, fuel inlet hose, and you need another person on the other side to place the thing on sawhorses. Then you can get access to the pump.


This is an AC/Delco Chinese made fuel pump. I think the filter element is too small, but since I had the thing, I used it.




This is the original OEM pump and filter.

 

Wow this is getting old and expensive trying to figure this out. I just went and bought infrared thermometer. I'm reading about 20 to 30 degrees difference between the front and the back of the catalytic converter. I'm taking the reading on the pipe itself not the catalytic converter. I'm still ruling out the fuel pump. I've took readings four different times. The last time the needle was rock solid at 40 lbs and held pressure overnight and was still at 22 lb in the morning. It held at 40lbs for a couple of hours. My Mechanic said he test drove the truck with his fuel pressure gauge on the windshield and was solid 40 under load will driving.