View Full Version : Oddball


DirtyBeds
04-26-2008, 07:26 AM
Ok, got a 92 3.9L that likes to play a twisted game. It will run around fine all day, but once or twice a month it will not start back up after a short stop.
If I sit and wait between 2 to 20 minutes it starts and runs FINE. Untill yesterday when it pulled this stunt and stayed dead, I have fire, And Fuel Pressure at the rail, but no fuel goin into the intake.
I was told that the pump may not be delivering the RIGHT amount of pressure, but I have a feeling this has something to do with the computer... oh and the fuse-link under the power dist. box for the ASR has already been replaced... any ideas?
anyone else with a possesed 3.9?!

Shibby927
04-26-2008, 07:50 AM
You know my 92 3.9l 2wd did about the same thing. Ran great never had any problems but every once in a while I would be coming to a stop or slowing down into a turn and it would just die. Let it sit for a second and it would start right back up and it wouldn't repeat the problem for another good period of time, maybe once or twice a month at the most. Strange no idea what caused it and I sold it before I could try to figure it out you might talk to a mechanic well versed in dodge mechanics and see if its a common issue amongst the 92-93 model years or with the 3.9l in general.

codydakota
04-26-2008, 10:11 AM
Sounds more like a pump than the computer. Have you tried to pull the codes off the computer?

Airmanbeard
04-26-2008, 10:37 AM
check your fuel filter. might be something plugging it up.

Bad96_3.9
04-26-2008, 11:03 AM
sounds like the asd relay or the fse, i think dodgerules86 made a post on the faqs or how too section about the bad splice or what ever it is, lol.

Crazy4x4RT
04-26-2008, 12:02 PM
I agree with bad96

Shibby927
04-27-2008, 02:46 AM
Probably not the fuel filter, I replaced the fuel filter in my 92 and it still did it after the fact.

DirtyBeds
04-27-2008, 09:45 AM
Yup, Fuel filter is less than 600 miles old, ASD relay splice has been replaced and run since.
I got the flash codes, #17 Closed loop temp not reached or engine cold too long, which was set when the temp sending unit was shot, has since been replaced but I think it kicks that code due to the 180 thermo I left in it.. Supposed to reach 193-196 I think..

The other code was #37 Torque converter clutch solenoid CKT or park/neutral switch failure... But wouldn't neutral safety switch cause the ignition not to try at all? As I said, I have good strong starter spin, compression sounds fine, it acts like it wants to hit, and will if you give it a lil gas into the TB so I obviously have timing and fire, just no fuel delivery...

Ok can someone tell me how much pressure I should have at the rail?
And can a standard test light even read the 4Volt injector pulse?
If not how can I test for pulse?

DirtyBeds
04-27-2008, 09:47 AM
oh and just to be on the safe side I popped new relays in for fuel pump and ASD...

Bad96_3.9
04-27-2008, 10:03 AM
the make these little diodes that you plug in between the injector and plug and they light up if it is working. i think the fuel pressure is between 30 and 40, dont have my service manual with me so i am not sure. but i am not sure if you can rent the injector things or you have to buy them, a mechanic shop should have some though...

DirtyBeds
05-02-2008, 02:06 AM
got it runnin, had pulse goin to injectors, voltage in the harness to the pump and no pressure on the rails. New pump installed, good as gold.

Thanks a million for the ideas fellas!!!