Engine Performance problem
1998 Dodge Dakota 6 cyl Two Wheel Drive Automatic 148000 miles
fuel pump, spark plugs and wires, cap, rotor, inition module(round thing with a plug and wire inside the distributor) ASD relay, fuel pump relay, hooked to computer with a slight misfire on #2 cylinder is all. All the above is new. The truck sputters and dies at anytime, driving or idling, it cranks back up right off most times, sometimes not. It takes a few tries and a few minutes other times. After replacing the above parts and $800 USD's later.I have the same problem. Is there something else I can replace that I've missed?
Have you checked the idle air control motor? Vacuum leaks?
November, 3, 2010 AT 2:07 PM
(1)I found one port open at the manifold. Now plugged.
Still dies arbitrarly at high or idle speeds. Plugging the port seems to create more of the problem. It does seem to start back up quicker though.
(2)I unplugged the idle air motor while running. Rev'd it up around 2500 rpms. The engine was surging but still continued to run. Then at idle had a harder time but did not die.
(Comment)but get this, the security system started acting up a few months back. The engine would not start if the security system was at fault. You won't believe this but I just started the truck up after testing the idle motor (unplugging then replugging while running), I then locked the doors and took it for a spin.I do mean spin. No rough running, no valve clatter, good accelaration. Will it continue to do so. At every test, I check the fuel pressure first thing. Always had a squirt the valve but now I here the pump with a definite run and presure build up.
Still no definiitive conclusion as to where the real problem is yet. Is there an inline fuel filter or security shutoff that can either be by-passed or disabled? This is as close as I can guess on capturing this ghost. Probably a dead inlaw.
November, 4, 2010 AT 7:17 AM
The security system should shut the engine down and not allow it to start. I hate to say it, but there is no way to bypass it.
As far as the vacuum leak that made things worse, here is what I think has happened.
When you plugged the vacuum leak, less air was getting to the engine. If that made it worse, that tells me the IAC may not be working and allowing enough air to enter the vehicle causing it to run rich. When you reconnected it, it started running better. Something tells me that it wasn't working maybe due to a bad connection. Now that it is reconnected, it is working. Drive it for a couple days and let me know what happens.
November, 4, 2010 AT 4:33 PM
Truck did great to the store. Not so good after. Would not start after coming out of the store. Sat there and waited, tried, nothing. Got out of the truck and turned the key to unlock then lock then unlocked. Got back in. Truck started and ran fine up to around 30 mph, sputtered and slowed, then picked back up and ran fine.I pulled into a local shop that has a good rep. Talked to the owner who said they had a similar problem with a dodge truck a few weeks earlier that turned out to be a loose wire at the door key switch causing the security system to do a complete shutdown just as I have talked about. He also recommended that I replace the fuel pressure regulator.I think I'll take it to him in a few days and see if they can find a problem in the wiring. Thanks for the help. If anything definitive is discovered, I'll let u know so u can put it down for future reference.
November, 4, 2010 AT 4:36 PM
Let me know. Also, why does he think the regulator is bad? Was it checked?
November, 4, 2010 AT 7:28 PM
He said that another problem a customer had had earlier was at the regulator.I suggested that I could change it to try and cover all the bases. The pressure has always been good though.I will change it and drive for a test.I doubt that that is a problem though. If it still dies, I will then examine the wiring harness and door wiring. If there is nothing obvious, I might take the rail off and add a 2b carb. Get rid of all the junk.I will get it reliable.
November, 4, 2010 AT 10:18 PM
Before replacing the regulator, I would check it. Why waste the money. If you need directions, let me know.
Also, I would think that a fuel pressure issue would affect more than one cylender. As far as the carb, I wish it was that easy.
Let me know.
November, 8, 2010 AT 2:50 PM
I'm possibly dealing with more than one problem. I've unplugged the IAC. The engine does not die now at all unless I let off of the gas petal while idling. So I'll replace the IAC, then try it and then look at the pressure reg. The truck will not shift into high gear while the IAC is unplugged, don't know why that is but ok.I had a ford EXP in the '80's.A loose ground wire located under the front right headlight. This caused the engine to die, the wipers to run without being switched. The radio to play etc. All from a loose wire. Drove me crazy till a buddy saw a blue arc under the headlight when I dropped him off one evening. We tightened it up and no more problems. If this is an intermittent problem, it may never be resolved without major money. I bought an 02 jeep in 01 new. Within 3K miles I had an intermittent problem with the engine dieing. Turned out to be a wire in part of the harness that was rubing on the transmission. Another head scratcher. Mechanic kept it for 2 wks to find it.I will continue with your advice till we have definitively found the problem. It's personal now.
November, 9, 2010 AT 7:13 AM
With the IAC unplugged, it will stall unless you keep your foot on the gas. The IAC does nothing more than allow additional air to the engine when the throttle plate is closed. If you open it with the throttle, it will / should stay running.
It sounds like you have had some real headachs over the years. Let me know what you find.