Hello, I have a 1992 Dodge RAM250 Roadtrek 318 engine that is acting very weird..

It stars perfectly when it is cold, after the engine warms up, (10 to 15 Miles) if I shut her down, it will start OK for maybe 10 minutes and the "no go".

When this happens, the "check engine light" does not come on, but all other test lights are OK, the ASD and fuel pump relays do NOT click and the pump does not hum...

When the engine is again cold, 1 to 2 hours, it does start perfect...

I checked the ASD and fuel pump relays they appear OK. My next move is to check voltages at these relays in a NO start condition.

I sort of suspect the PCM.

Any ideas..

Fern[/align]

 

Mine was like that but it would act up when cold, then it got even worse where it wouldn't start at all without some work. When doesn't the pump hum? It is suppose to when you first turn the key on for a couple of seconds to prime the system. If it doesn't it might be part of it. That's what mine ended up being, the computer got a used one for $100. See me if you want one cheap, i'll give you a couple of numbers of people that might have some.

 

The pump does NOT hum in the NO start condition, that is when the engine is hot..
No ASD or fuel pump relay clicking, no pump huming and NO test "check engine" lite....

What is your location.. RE: computer.

 

Maysville, KY bu the places i have are in Ohioone deleivered to me froma salvage place near columbus for 100 bucks, shipping uncluded. It took them two days ,UPS freight and only cost $100 what a deal.

 

Your fuel pump may be going bad. Before you buy a computer, you should check your fuel pressure at the rail. A guage at a parts store is 10-15 bucks. Many times when a pump is begining to fail, they work for a bit. After they warm up, no-go till it cool off again.

 

If you do check it with everything attached, then remove the pressure regulator vacuum hose and check it then too, i should increase. 31-33 with vacuum attached, 39-41 with it removed. Then after you attach the hose back if the pressure is low you are suppose to pinch the return line, but if the line is stainless braid you can't. So you have to rig up some kind of rubber hose, if the pressure stays the same there is a leak or pump is defective. If pressure rises sharply, replace regulator. If Ok when vacuum is connected but not ok when disonnected check for vacuum at line, if present then pinch line again and see if the pump is able to reach the disconnected pressure reading replace regulator.

 

I do not understand how the fuel pump would cause the test "Check engine" lite NOT to come on, and prevent the ASD and fuel pump relays not to work....
I pretty well trace the problem to the PCM...
After a got home from a ride, I place a domestic fan in fromt of the PCM, so it would not get hot after I shut down the engine and kept turning the ignition key to on every 2 minutes for 1/2 hour and never got the situation I described at the begening of the thread.....
I will test again tomorrow...

Fern

 

The computer will not read a fuel problem code. It would only read a code if the pump caused a problem with another part. But if a fan cooling it does rid the problem i say the computer is bad. Actually the ASD and Pump relays make the pump run, without these the pump won't work at all. The pump reliese on those to work.

 

Think of it like this... If you ran the gas tank dry, would your engine light come on? No, it would not, the PCM has no way of knowing if the lack of pressure is due to an outage of fuel or a malfunction. Now do you "get it?"

PS If you didn't want any ideas and olny wanted someone to just agree with your quick and rash replacement idea, next time don't waste our time and just throw your money at it. I`m sure the part store or dealer would love to take your cash!

 

If I run out of gaz, I assume/think thatthe engine light would come on as a test when I first turn the key to the ON position, I understand that it wont come on if I run out of gaz while driving....

PS I am not trying to waste anyone 's time just trying to solve a problem
Thanks anyway..