pyromick Posted September 12, 2009 Share Posted September 12, 2009 OK so last week i was hooking up my amplifier in my 1989 pioneer 2 wd 4.0 five speed and in my haste to hear my subs i didnt take the fuse out of my power wire well i grounded it out on my amp...fried the amp and my something in my truck...it will start and run for 1 to 2 seconds and dies i have fuel to the fuel rail so my pump seems to be working....it will run fine on carb cleaner so its not anything with iginition....i have a extra computer so i put that in there and still no change....Is there a ecm fuse on the 4.0 or does anyone have any ideas on what could be goin on...please help! Link to comment Share on other sites More sharing options...
Geonovast Posted September 12, 2009 Share Posted September 12, 2009 Check your fuel pump ballast resistor. If it'll run for a few seconds than die, that's a likely culprit. Link to comment Share on other sites More sharing options...
pyromick Posted September 13, 2009 Author Share Posted September 13, 2009 is that the ceramic thing on the drivers side of engine compartment and how would u test it Link to comment Share on other sites More sharing options...
Geonovast Posted September 13, 2009 Share Posted September 13, 2009 is that the ceramic thing on the drivers side of engine compartment and how would u test it Yes it is. There's two ways to test it. Pull the wires off and jump them together to bypass it, just get a small length of wire and two blade connectors, or replace it with a known good one. Link to comment Share on other sites More sharing options...
BlueXJ Posted September 13, 2009 Share Posted September 13, 2009 They are pretty cheap at most auto parts places. Were used on many Chrysler products from the early 70s until mid 90s as well as Renix era Jeeps. Link to comment Share on other sites More sharing options...
Geonovast Posted September 13, 2009 Share Posted September 13, 2009 It was used in HO Jeeps as well, until sometime in the mid 90s Link to comment Share on other sites More sharing options...
pyromick Posted September 13, 2009 Author Share Posted September 13, 2009 bypassed fuel pump ballast resistor still nothing any other ideas Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 13, 2009 Share Posted September 13, 2009 Next step, you need to put a fuel pressure gauge on the rail schrader test port, start it up, and see if the pump maintains pressure. Then we can go from there. I'm thinking ASD relay because there's no sustained fuel pressure. Link to comment Share on other sites More sharing options...
pyromick Posted September 14, 2009 Author Share Posted September 14, 2009 ok ill get a fuel pressure gauge morrow after work...what is normal pressure for 4.0s Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 14, 2009 Share Posted September 14, 2009 39PSI w. vacuum line disconnected from the regulator, 31PSI w. vacuum line connected. Link to comment Share on other sites More sharing options...
pyromick Posted September 14, 2009 Author Share Posted September 14, 2009 ok thanks... is the asd relay one of the four on the passenger side cause i switched those around with each other and nothing changed....if not where is it located? Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 14, 2009 Share Posted September 14, 2009 Just noticed you have an 89? I believe in the Renix they call it a Latch relay - maybe some of the Renix gurus will jump in. But still check the FP first so you can perhaps eliminate that. :cheers: Link to comment Share on other sites More sharing options...
Wildman Posted September 14, 2009 Share Posted September 14, 2009 On the right shock tower, front to rear, Fuel pump relay, O2 sensor preheat, B+ latch relay, and if you have AC, the 4th relay will be for the AC pump. maybe some of the Renix gurus will jump in. No guru here, still learning the Renix system :wall: Link to comment Share on other sites More sharing options...
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