Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
1988 Dodge Dakota 3.9 TBI intermediate No Start. This one is driving me nuts trying to find the problem. The bad part is I can't hook my Snap-on Verus scanner to any Snapon scanner for that matter. I had the sale guy bring everyone they make and none will hook up. But I paid someone with a Genesis and it got right in a while back just to find out if it was the computer that was the problem or not but it was working fine. Talk to Snapon and I was told they were going to fix the problem needless to say I'm not real happy with Snapon after spending $8000 on this thing.
Anyway, this has something weird is going on here. This truck runs fine most of the time. or was, it's getting worse over time. It really acts up when you get it hot or after you have driven good ways. You shut off go in someplace come back out and it will not start. Yesterday it finally did it at home where I had someone here to work the key. I had my wife crank it over for me so I could see what was going on. I found it was getting fuel and spark both it just won't fire up at times. I check for codes using the key and found nothing. I check the fuel pressure a few times even when it won't start and it was good.
I found that sometimes if I cycle the key a few times it will start. Them other times you may have to hold it to the floor to get it to start and it's loaded up then. Then sometimes when you do this it sounds like it's sucking air or not getting fuel and it will die even when you're holding it to the floor.
Here what I wondering but I trying to figure out how I can prove it. I have problems with the EGR value for 15 years on this truck I replace the value and vacuum controls a few times because the EGR code will set on long rides. I'm wondering if the EGR valve is not closing sometime causing it to suck air and causing a no start. I can't put my fingers under it to hack because it's solid. It's about the only thing I can think of that could cause this kind of No Start while getting fuel and spark. If you have any other ideas I'm all ears...
A faulty coolant temp sensor can cause a hot crank-no start with fuel and spark.
PCM thinks the engine temp is -40° and gives it WAY too much gas for a hot engine.
I like your EGR theory too. When I suspect an open EGR on something with no data I remove the valve and block the port with a piece of cardboard, gasket, beer can what have you and see if the symptoms improve.
