98 4.0 Interiment Missfire

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May 15, 2019 | 11:39 AM

#31

dpeterson3

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I would check, but I ran down the battery trying to get it restarted. Would not try when the wrecker driver tried a jump pack. I am going to get a new battery later today since the one in it is bad. I had it checked right before the truck died adn it came back as having bad cells. Its 5.5 years old. I am thinking now that it could be low enough its sucking enough power trying to start that the PCM isn't getting enough to stay alive and start the engine. Either way, I won't have codes since I pulled all the fuses and relays in the box (including PCM memory) to clean them in case that was the problem. Had to be on date night when my wife was already afraid it wasn't reliable too.

May 15, 2019 | 12:56 PM

#32

pawpaw

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From: SW Va

Good idea to replace the battery if its giving problems, as it can cause the computer, ignition & fueling systems to act out.
Be sure to use your smart charger to top up the new battery before installing it, then check out the charging system under load, to make sure its able to keep things happy.

May 16, 2019 | 09:04 AM

#33

dpeterson3

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Something electrical failed for sure. Got a new battery this morning, and still no joy. I don't hear the fuel pump prime or relays click open, so I think its probably something in the master power path to the main fuse box or pcm power line. I would use a smart charger and do some load tests, but I don't own one. Can't have someone else do it since the truck won't start. Going to start back probing the power paths and see what I come up with.

May 16, 2019 | 09:39 AM

#34

pawpaw

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From: SW Va

Check the condition of the battery cable end connection lugs & clamps. No corrosion where the wire strands go into the end fittings. Perform voltage drop testing on the wiring run of Both B+ & B- cables & make sure the B- cable is making a good connection to the engine block & body. Also check the B+ cable fuse link to make sure it isn't blown, or has a faulty high resistance connection, maybe do a wiggle test on the cables to see if things suddenly wake up from a faulty connection. Seeing as we only have 12 volts or so to work with, All connections need to be clean, bright & tight.
Let us know what you find.

May 16, 2019 | 10:33 AM

#35

dpeterson3

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Found my power problem. When I fixed the minor injector issue I had a couple of days ago, I got the noise cap wire stuck under the coil pack and cut the insulation. Over time, it vibrated over to a screw and grounded out to the frame. It happens to be on pcm power relay and spark plug circuit, so it blew out the fuse preventing the engine from running. Cut the bad section and spliced in a new wire, so that's one gremlin down. Next is the power steering leak. Going to change the oil while I'm at it. Mercon V or type F? I can't seem to find a consensus on which to use. Thinking F since I already have some on hand.

May 16, 2019 | 12:25 PM

#36

pawpaw

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From: SW Va

Ok, good find, fix, feedback & to hear the no run seems fixed.
On the power steering fluid, refer to your owner manual call out for the prope power steering fluid. My 99 specifies Mercon-V, so that's what it gets every 30K miles when I do a full fluid pump-out / fluid exchange in the tranny & power steering systems..

May 27, 2019 | 08:24 AM

#37

dpeterson3

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Its been about a week and 200ish miles, and it seems to be running ok. CEL is still on, but it is just P0442, and that was a problem before I started working on the motor. I suspect I have a leak somewhere on the back end as all the rubber back there is original. It still seems to be missing some power to me. Before it had problems, I could put it into 4th gear getting on the interstate at about 1800rpm, and it would pull no problem. At the moment, I seem to need to run it up to about 2500 before shifting, and even then, it still isn't pulling (no extra load of course, just me driving to and from work). Not sure if I damaged the cat with all the oil it was burning or just didn't clean something properly while I had it apart. Any suggestions on what to check?

May 27, 2019 | 11:38 AM

#38

pawpaw

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From: SW Va

On the P0442, evap system small leak detected code, inspect the condition of the system vacuum hoses & the fuel cap rubber seal & its fill tube sealing surface, also the fill & overflow tubes condition.
If all seems ok, perform a smoke test to find the small leak, or if you suspect the gas cap & want to toss a part at the problem, replace the gas cap with a OEM part & see how it goes.
If no joy with the new gas cap, revert to the smoke test to see if you can spot the leak. Also use your nose to sniff for gas fumes to try & narrow down the suspect area some, then do the smoke test & concentrate on the suspect area to try & spot the small leak & let us know what you find.