How are you guys. I have a question. Just rebuilt my 3.0 v6 for my 94 caravan. When its cold it cranks right on up but it want stay running for more than 5 minutes. Soon as it warms up and get hot it slowly stalls and quits. It want crank up untill it cools down. I installed a new fuel pump, filter and fuel pressure regulator. Is it something internally wrong with my engine?

 

when it get's hot my oil pressure light comes on. When that happens it stalls out and quit. I try to crank it up and it doesn't start anymore until it cools down. Has anybody had this problem?

 

I am not familiar with your engine; so when it quits and you try to restart, will the engine turn over quickly, or is it seized?

 

not seized at all. the engine turns over just fine. When its been running and its warmed up after it stalls out it'll fire up for 2-3 seconds and quit or might run at a very low RPM then quit. Sometimes it'll fire up and run normal and the oil pressure light is still on. Then it'll stall out and quit. Like I said, it's rebuilt and I just changed the oil to hopefully to solve this problem. I have Pennzoil 5w30 in it. The other oil was Castrol 5 30 and it had more of a dark tint to it when I drained it. I'm guessing it was from the fine debris from the cylinder wall honing job I had done to it.

 

So when it stalls and then fails to start, do you have sparks and fuel? A quick and easy test is to spray some fuel into the throttle body with the throttle plate open. If it fires then you have a fuel problem. If not then perhaps an electronic ignition problem, usually internal short due to overheating.

Can you replace the oil pressure warning light switch with a temporary oil pressure gauge that is not electrical to confirm whether you have an actual oil pressure problem or an electrical problem that may be affecting the ignition system as well.

Good luck.

 

I don't have a oil pressure gauge but I'm bout to buy one now. The spark and fuel is fine. Matter fact, sometimes when it starts to stall out it does flood out. I would just unplugg the injectors main connector harness and start it up to burn the unburnt fuel. I just ran it till it got operating temp and it stalled out again. I took the valve cover off to inspect the valve train. Its well lubricated but the oil's viscosity is just like water. I took off the oil filter and it was like water pouring. Can oil this thin cause my engine not to run? Like I said, I got 5w30 pennzoil in it.

 

Sounds like you are getting way too much fuel into the engine. The excess can cause fuel to dilute the oil making it thin out. Can you smell gas from the oil? Have you pulled a few spark plugs (both banks) to check their colour? The plugs would be black from soft carbon and probably wet from fuel.

If the ignition were to stop firing the plugs the engine would stop immediately. If the fuel is saturating the engine then you would notice very poor running leading to a congestive stall. The engine would be more tolerant of over-rich mixture when cold and not tolerant of an over-rich mixture when hot. The excess fuel is probably leaking down into the sump and diluting the oil.

The electronic engine management would use engine temperature to help identify fuel requirements. It would support a cold start in open loop and use a mapped setting to run the injectors until engine and O2 sensors are up to minimum temperature and then go into closed loop operation where it would use the MAF sensor for intake air and O2 sensors for oxygen content of the exhaust to manage the fuel injector pulse width and on timing.

So I would check the fuel pressure as being excessive (blocked fuel return line), perhaps because of a pressure regulator problem. You may have two engine temperature sensors, one for the temp gauge/light and another for the electronic engine management system and that one may be faulty. The temp sensors are usually tested by resistance varying with temperature. Are your O2 sensors connected into the harness?

Excess fuel going into the CAT(s) will overheat them and lead to blockage or operational inefficiency (DTC P0420/P0430).

Good luck.

 

OK, just realized that my oil pressure light comes on when my RPMs get low and that's probably when the flooding starts. when you said it get hot that the air/fuel ratio is less tolerant to rich mixtures. I'm gonna start over with my ignition system. The ignition coil, and new spark plugs and wires. The spark plugs are denso platinum and they were on sale for 2.50 a piece. Everytime I pull them they are saturated with fuel and carbon has caked up. Gonna switch to the regular nickle champion plugs. The distributor cap and rotor is brand new.

 

Did you check the engine coolant temp sensor?

 

That's something else that might be wrong. My lower intake manifold was seized onto my engine from it running hot so many times. When I took it off I damaged it. Along with new heads, I got a new lower intake from a 97 caravan 3.0v6. I found out that 94 3.0v6 and the 97 3.0v6 or slightly different. It didn't have the 1-wire coolant temp sensor spot to put the sensor. The wire is purple with yellow stripe. The 2-wire coolant temp sensor is connected. I thought this 1-wire sensor was for my temp gauge on my cluster