I have a 92 ram 150 with the 5.2 liter magnum engine, I am rady to shoot this truck. The truck runs perfct till it hits temperature, when the truck gets to temp it spits, sputters, backfires and runs like crap. When its running like this it misses abd backfires every time I try to give it gas. I have read over 100 posts on this and one seems to be able to solve the issuue.

Repalced so far
Plugs
Wires
Cap
Rotor
O2 sensor
Pickup in dist
Computer
MAP sensor
Throttle position sensor
Coil
Temp sensor on intake - 2 wire one
redid all teh grounds on the truck

I am into this thing for over $1500 an no one has the slightest clue on whats wrong. I also used a fuel prssure guage and when the truck is acking up I am still getting 35psi of fuel guage does not jump. When the truck is good and hot for a while it will again seem to run fine. Someone please help me

 

Just take out the thermostat and it wont hit the running temp =P

 

92s used both TBI and MPFI, which do you have? Have you read the codes and if so were there any? Have you done voltage checks or are you just replacing parts for troubleshooting? It sounds like something is braking down electrically when it gets warm.

 

Its the magnum system that has an injector for each cylinder. does this answer if its TBI or MPFI? I have tried everything. Should I try the other temp sensor at the front top of the block with the single wire? Not sure what one gives the computer the info and what ones gives the temp guage on the dash the info? Another thing I found on the interior, you knwo the big wire harness that comes out of the fuse box? about 10" from the fuse box tie wraped right to the harness is a relay, it has 4 wires Yellow, Red, Purple and white/ and grey/greenish and black, anyways none of the wires are hooked up to anything they are just hanging?

 

One other thing I found odd or maybe not, you know the temp sensor with two wires that is higher up in the intake at the front with the two wires, the old one was pretty oily should oil be up at this level of the manifold? Strange thing is the truck runs perfect cold and it runs perfect when it is hot, its the switch between cold and running at temp that is screwing the truck up, When it messes up if you wait 1/2 hour and the trcuk is still hot you can start it and drie it with no issues.

 

the temp sensor with the 1 wire is the one that is for the temp gauge

 

MPFI is Multi Port Fuel Injection and that is what you have. The two wire sensor is for the computer and there should not be any oil there. Have you read the codes and if so were there any? Have you done voltage checks or are you just replacing parts for troubleshooting? The parts you have replaced are only part of each system. Voltage checks are needed to check each system to include the wiring.

This problem will be very hard to troubleshoot since the problem is so intermittent. All troubleshooting will have to be done while it shows the problem.

I will bet your seat belt buzzer doesn't work. That relay is probably a reminder buzzer.

 

has not thrown any codes, so If the two wire temp guage has oi on it and it shouldn't what does that mean? anyone want to buy a 92 short box LE full load?

 

Someone told me there is an easy test to see if the intake manifold gasket is shot, I can't rmemebr it something about blocking the PVC valve hole and feeling the snorkle for air blowing out or in or something

 

A blown intake gasket would show up at idle so I would not think that is your problem from what you have posted. Clean the oil up, especially inside the connector as it could be shorting the sensor output and be the cause of this problem. You need to understand that the temp sensor is a variable resistor with certain limits. Even a slight ground at the terminals will cause problems. Someone may have spilled oil on it but other than that I can't think of anything that could put oil there.