1996 ford explorer 4.0 OHV hard start

[Whosred370]

Hello forum fellas im new here so hopefully im doing this right. I have a 96 ford explorer 4.0 ohv when it is cold it fires right up but instantly dies unless you hold it half throttle or more. When you do that it reaks of raw gas and spits anf sputters, kind of sounds like its cammed for about the first 30 seconds its running. After that it runs perfectly fine. Once you shut it off it will fire back up fine but if it sits for a couple of minutes it does the same thing.

I've replaced the o2 sensors, tps, maf, plugs, wires, coolant temp sensor, and a few other things.

It has a - P1000 code (obd2 system checks incomplete) and a P0402 (EGR excessive flow detected)

I ran some test with the snap on scan tool and the egr valve sounds like it is working.

Im kind of at a loss as of now. I haven't got a chance to leak down test or compression test it but im curious about that EGR code. Would that cause it to flood out if that is not working on cold starts?

Engine has 95k miles on it and no fluids are mixing

 

[franklin2]

If it's easy to do on your engine, I would block off the EGR temporarily and see what happens then. That would eliminate it completely as being the problem. Having it blocked will not keep the engine from running, actually you would not know much difference except it would throw a code for no flow in the EGR.

The EGR put exhaust gas directly into the intake of the engine. So if there is a problem with it, it can act like a huge vacuum leak.

 

[I support common sense]

Check for any vacuum leaks around your egr valve and the dpfe sensor. If there are leaks that is probably your issue. If not take off your egr valve and stuff a towel or something in the hole in the intake. The exhaust may be loud as the headers are now open. Start the engine without the egr and see if the issue occurs. If not it’s fixed, and I would proceed to cleaning the egr valve. If you can look at the live data with a scan tool check and see what the long term fuel trim is doing. It’s probably trying to trim it down really hard at a -20or30.

 

[Whosred370]

Thank you guys! Im going to give that a try once im home from driving truck. I went ahead and ordered a egr valve as they are only 30 bucks and the piece that has the vacuum lines going to it. Im going to also replace the o rings in the tube that goes in to the intake but while I have it off im going to block it off and start it to see what it does before installing the new parts.

 

[I support common sense]

The “thing with vacuum lines” is your egr dpfe sensor.