Need trouble shooting help with a Dodge truck...

[flatie46]

I know this is a great place for Jeep info an I know it's off topic but I was wondering if I could get some help with trouble shooting a problem with my sons '99 Dodge Ram 1500 4x4?

There are times he can be driving it and the engine will just die. Almost as if you turned the key off. It doesn't act as if it is starved for fuel (bucking and feathering out) it just dies. If you try to start it right after it will not fire up but if you wate 2min it will crank and run like nothing happened. The speedo will drop but all the other gauges freeze where they are.

We drove it this evening to see if a code would pull up but they said it was like it had no power to the port where you plug the tester in. The check eng light quit working at some point. So trouble shooting is a pain. The truck is has the 318 in it and has 140,000 miles on it.

This evening we drove it aprox 15mile and it didn't have any issues. My son is afraid to depend on it though and I don't blame him. If you have any ideas or suggestions let me know. Thanks a bunch. Flatie46

 

[carnuck]

Swap out the ASD relay and fuel pump relay then check the electric connectors for corrosion.

 

[JPNinPA]

Did you try the key dance for the codes? It works on many vehicles.

Clean battery connections. Verify it has proper voltage 12.6 off and 14.4 running.

A failing CKP will cause the shutdown issues without throwing a code.

 

[flatie46]

2 questions...what is an ASD relay and whats a CKP?

 

[greg92jeepxj]

ASD is the auto shutdown relay . PCM will shut down engine if low oil pressure or hot engine / low coolant condition exists. CKP is the crank shaft position sensor which tells PCM exactly what degree of rotation the engine is on during cycle . PCM must know this to establish correct firing order of ignition and sequential port fuel injection order. The CMP , cam shaft position sensor also assists here too.

 

[flatie46]

Thank ya so much, we'll be digging into this thing this week. I really didn't know where to start. I'm old school, these new fangled putor controlled vehicles stump me pretty quick. Thanks guys, Happy Easter!

 

[greg92jeepxj]

Your most welcome best of luck and Happy Easter to you and family !
Although your son's rig is computerized , still got to have spark plugs and fuel/air mixture to get it Rollin' . Just that someone got sick of carburetors and used fuel injectors and some ignition systems are powered by the computer rather than the ignition switch to better control advance/retard. Just guessing , but a good start as suggested is to of course clean all electrical connections , especially those computer grounds. Usually they are found where all other grounds are under the hood on the engine block but not really knowing that truck , I'm just surmizing.
Going after the crank sensor ( cam sensor if it got one to ) is a good place as the computer is literally blind without feedback from it. Won't know the engines spinning , therefore won't be able to tell piston position for electronic injection firing and spark timing too. This kind of hot stall sounds like a bad ignition coil but since we're dealing with a computerized engine , can't forget them cam and crank sensors. They do most of the talking for the ignition and fuel system .
Yeah, electronics make it tough to just put a test light on a positive post of a coil and call it good , I hear ya , but I guess that progress . Never took too long to find a no start on my old '66 Chevy or '78 jeep cherokee. But I had to change with the times when I got my '92 XJ and even my '83 & '85 g-body mid size GM cars ( when I had them) . All things being equal , I'd rather be rebuilding carb's again. Can't rebuild an injector and they cost WAY more !

 

[flatie46]

Yea an to think I've been considering an LS1 swap in my Scrambler.

 

[greg92jeepxj]

Yea an to think I've been considering an LS1 swap in my Scrambler.

i like the way your thinking brother ! I'd say mount it up and we'll worry about the wiring later !
Its been done in a lot of chassis so I think the scrambler ought to be fun !
if for any reason the LS1 swap proved daunting ( I doubt you would be intimidated) or too $$ , maybe an LT1 ?