94 Ranger warm starting problem

[cndplus2]

I'm having an intermittent problem with my truck re-starting after it has been running for awhile. Normally it happens after I have driven it for a while and then try to re-start it 15 or so minutes later. I have replaced fuel pump, fuel filter, plugs and wires, and ignition coil (it was bad). Sometimes it will restart in 10 minutes and other times it takes hours. Motor turns over fine, it just won't start. Can anyone offer any suggestions as to what the problem may be?

[fordtruckman]

I have been having this problem now for a couple of months on my 98 4.0 Ranger. It only happens once or twice a week. The shop can't get it to happen so the can't tell me what is wrong. I have determined that I am getting fuel and that I have no spark when the problem occurs. When it cools down enough it just starts and runs like nothing was ever wrong. Let me know if you figure it out and I'll do the same.

[lmeade]

Same here. I have a '94 Ranger, with the 4 cyl. engine. After it has run awhile, and I turn off the engine, it will not start for awhile. I assumed it was something in the fuel or spark plug related. I have replaced everything you mentioned except the fuel pump, which was my next guess. Yesterday & today it started something new. It cut out on me while actually driving...about half-way to work it dies as if someone just cut off the fuel supply. Again, after letting it sit for a few minutes it starts right back up as if nothing was ever wrong. Yesterday I disconnected a vacuum line that attaches to the fuel injector bar. It started right up. However, I don't know if this is indicative of the problem or if it was simply coincidental to the time the engine had to set before starting again. If you come up with any answers please post. Likewise for me.

[seether57]

I am having the same problems described above with a 1994 Ranger V6 4.0L. Another indication the truck won't start is the CEL does not, repeat, does not come on. The truck starts and runs fine when the CEL comes on at the initial turn of the ignition key. Code says it has something to do with the EGR system. I am going to try replacing the Differential Pressure Feedback EGR (DPFE) Sensor. I'll let you know if it works.

[stuzman]

Originally Posted by seether57

I am having the same problems described above with a 1994 Ranger V6 4.0L. Another indication the truck won't start is the CEL does not, repeat, does not come on. The truck starts and runs fine when the CEL comes on at the initial turn of the ignition key. Code says it has something to do with the EGR system. I am going to try replacing the Differential Pressure Feedback EGR (DPFE) Sensor. I'll let you know if it works.

My 94 Ranger had a problem with the DPFE. I replaced it and that took care of the problem. When you take the hoses off the sensor, you will probably find a lot of whiteish buildup from the exhaust manifold. Be sure that the hoses are free of this debris. Otherwise, this material will get sucked into the new sensor.

[stuzman]

Originally Posted by cndplus2

I'm having an intermittent problem with my truck re-starting after it has been running for awhile. Normally it happens after I have driven it for a while and then try to re-start it 15 or so minutes later. I have replaced fuel pump, fuel filter, plugs and wires, and ignition coil (it was bad). Sometimes it will restart in 10 minutes and other times it takes hours. Motor turns over fine, it just won't start. Can anyone offer any suggestions as to what the problem may be?

Check your crankshaft sensor and/or ignition module.

[fordin K]

ok I have one too. because it was neglected. we changed spark plugs, cleaned egr valve and port.
first cleaned iac then replaced it. replaced fuel filter, o2 sensors ( all), dpfe, cpu and upper intake gaskets. does that kill all the birds not yet. tomorrow will "sub" in a MAF because LT fuel trim is at 25%. disconnected it still reads 25% but goes to 0% on throttle. baro reading is about 2000ft off so am thinking it is bad. cleaned already. for you guys with the no start after 15 + minutes it acts like a vapor lock and if you take the cap off the fuel rail and CAREFULLY push the valve in you'll see what I mean. put a rag and wear goggles. if anyone finds the real reason. let us know !!

[seether57]

Originally Posted by stuzman

Check your crankshaft sensor and/or ignition module.

I forgot to mention that after my 120,000 maintinance in July, the Ford dealer told me the codes were showing a bad EEC and CKP. I replaced the EEC IV and the crankshaft position sensor myself for about $250 (about $500 less than the dealer quoted). It worked for a month than the same problem reoccured. I replaced the fuel filter and it ran fine for a week than reoccured. I'm still working on it. Plan to get the DPFE towmorrow.

[fordin K]

ok update. checked fuel pressure was at 10 psi when it started loping. at 8 it stalled. it never broke 18 psi. normal is 40 resting. 30 engine running. lekdown was normal held for long time. changed fuel pump. working fine ever since. pressure goes strait to what is supposed to. try checking your pump pressure. my friend said pump was changed twice before !! but with older style pump/sender unit.

[seether57]

Got the new DPFE sensor on Oct. 18th ($59). Waited till the problem happened again to install it. On Mon. Oct. 24th it wouldn't start so I put the new sensor in... still wouldn't start, put my tools away and tried one more time. It started and I haven't had the problem since (knock on wood). The weather has turned colder in Oakland, CA and that might be way the problem hasn't reoccured. I'll let you know if it happens again.

[barster]

I had the same senario with my 94 Ranger...after going through all kinds of tests it turned out to be my connector at the fuel pump..it would occasional arc. Have a mechanic check the voltage going to it on a scope...if it's low at all that's probably it...it can and will start at a lower than normal reading..but that's an indicator that it has 'issues'. Let us know what happened.