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98 Dodge Dakota 4x4
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98 Dodge Dakota 4x4 with 3.9. Truck originally quit on me so I put a new fuel pump on it once I done that it started up and ran 15 mins or so then died again I went inside for 20 mins came out started it up again and it backfired so hard it litterly blew my muffler off, now it will start sometimes but only run 10 mins or so before shutting off. I can smell fuel so I checked to see if it was getting fire and it's not. If anyone can help me out I'd greatly appreciate it. Also if anyone has a complete diagram of this trucks firing steps I might could track down the problem by using process of elimination. Thanks guys.
111191
 

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My Dakota is an '03, so I don't know that the troubleshooting I did on mine when it was in an intermittent crank-but-no-start mode (which devolved to a terminal condition) would be applicable to yours.

When it was intermittent I threw some parts at it (relays and both the crank & camshaft position indicators). When it became terminal I got into my Haynes & I will roughly quote the procedure I used, when I determined that I was not getting spark, to determine that my PCM was the fault.

Keep in mind that the Haynes I used to troubleshoot mine lists its applicability '00 to '04 (therefore the wire colors listed may not be the same on yours) & a FSM for your year & model would be much more desireable.

From Haynes:
"test for battery voltage to the coil by disconnecting the connector from the coil & using a MM to check for volts at the dark green/orange wire with the ignition ON.

No voltage=bad ASD relay.
If volts: use the ohm-meter function of your MM & check primary & 2condary resistance of the coil. My Haynes lists 0.95 to 1.20 ohms & 11,300 to 13,300 ohms respectively, but I believe Haynes is giving me inaccurate specs on that.

If coil ohms out good: check the trigger signal from the PCM. Using an LED test light (inexpensive from Advance or the like) back probe the coil driver terminal (black/gray wire) & check for a flashing light as an assistant cranks the engine.

If no flash: then check the operation of the cam position sensor & the crank position sensor.

If those sensors test good: send the PCM out to be diagnosed."
 

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Just had a similar but a little different situations
On my 99 with the same engine. Came down to something I didn't think could possibly be at fault because it would up being something that I had just replaced like 4 months ago.
Had started getting a misfire, and it would occasionally die especially when first starting and taking off. I went ahead and threw a coil and a distributor pickup on beccause they were original from new and I'd just done cap rotor and plugs like 6k miles ago. so I didn't think about those being the issue. But as it turns out I had 2 terminals arc gouged out and ate away with cracks starting to extend towards center of roof of the cap.
This was a "better grade" Napa Echlin cap.

At work, I've seen a 318 in a 2001 full size pickup, that had the whole coil terminal arced out and actually busted out of its distributor cap before. That was an original cap, on a truck with about 115k on it, at the time.
On mine, I re replaced the cap and rotor, and had them warranty out my lifetime wireset, since the plug boot on #2 and the dist cap end of the coil wire were also burnt. That wireset was on its 2nd set of plugs, about 40k on them. So far so good.
A good tune up with the better grade of parts is never a waste of time or money anyway. Just basic maintenance there.

Oh and 1 other thing/ that Haynes manual will serve you better as fire starter for a bonfire than it will serve you to fix your truck. They are almost worthless
 

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It was the intermittent nature of the issue that made me think of the (sort of similar) problem that I had & the troubleshooting that drove me to the PCM. Also that OP stated that, at least on an intermittent basis, he is "not getting fire", & I assumed he meant from his coil but it could be he only checked at the plugs.

I would probably amend my advice to determine whether OP is getting juice from his coil & if so then to certainly look at the basics (cap, rotor, cam pos sensor if it is under the cap on that particular engine). If not, then I would probably say do the checks that I outlined from Haynes (12V at the coil? Trigger signal to the coil? Does coil ohm out good?) .

But I agree, the backfiring through the exhaust would certainly make me think of a timing issue or arcing between contacts inside the cap & I also agree that Haynes leaves a lot to be desired.
 

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C'mon Dodge - NEW DAKOTA
2003 Dakota Club Cab Sport 4.7L
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"Not getting fire" is a down south term for no voltage in the wires.... at least that's my familiarity with it. Not necessarily spark. I used to deal with our company service technicians, and the first time I heard that -- I told one -- I sure hope your wires aren't on fire. He just laughed.
 

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"Not getting fire" is a down south term for no voltage in the wires.... at least that's my familiarity with it. Not necessarily spark. I used to deal with our company service technicians, and the first time I heard that -- I told one -- I sure hope your wires aren't on fire. He just laughed.

I figured it meant no voltage (& no voltage at the wires means that there will be no spark downstream) but I wasn't sure if it only applied to at-the-plugs or if it could also apply to the primary wire from the coil not supplying the distributor cap with voltage.
 

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Oh and 1 other thing/ that Haynes manual will serve you better as fire starter for a bonfire than it will serve you to fix your truck. They are almost worthless
One of the things that Haynes does not mention when they are explaining how to check for voltage to your coil is that approximately two seconds after turning key to 'RUN', if the engine is not running or being cranked, the PCM will cut voltage to the coil via the ASD relay. Meaning that you need to have your MM hooked up & in place when you turn the key to 'RUN' so you can check for voltage there real quickly (either that or have an assistant turn the key to 'RUN' while you check with the MM, or what I did was have the MM set up where I could see it as I turned key to 'RUN' & then cranked the engine). (Something else Haynes didn't explain that I found out by trial & error.)

Yes -- a FSM would be preferable. Some day I may break down & buy one.
 

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the dying while hot and starting when cooling down is a big reason to check basic ignition parts and replace if you haven't, or in a while. especially things like the coil.

sometimes (not always) things like cap rotor and wires will do the opposite... if cracked and drawing moisture they will run like $#!t (if at all) cold and straighten out as the crack dries out, the spark can follow the moisture in teh crack to ground. or if cracked terminal to terminal it can cause multiple cylinders to fire at once, the "wrong" cylinder firing will be way off in timing and fight against the one that is supposed to be firing. Not talking much money or effort... pretty easy access on these trucks. make Damn sure the base ignition is completely good before going further. Dont assume.
 

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Well, sure, & sometiimes cracks (such as in the distributor) expand when they get hot & shut things down but start when they are cold.

But if my coil ohmed out within specs, before I threw another coil at it, I'd probably be inclined to check & see if I was getting volts & a trigger signal to said coil.. And with a '98 you could probably consider the cam & crank pos sensors as almost part of the base ignition.

. . . I checked to see if it was getting fire and it's not. . . . I might could track down the problem by using process of elimination.
So OP says he is not getting fire, & assuming that is at the plugs, I would think the next step would be to check & see if the distributor cap is getting fire. If it is, sure, figure the problem is after the coil but before the plugs & check (& replace if need be) cap, rotor, cam pos sensor. Have the distributor, itself, bench checked. But assuming the distributor cap is NOT getting fire, I would think that the next part in the chain would be the coil. I think it would be faster & easier to check for volts & trigger signal to the coil than to check the coil's primary & secondary circuits resistance number, but do it in either order. If the coil's numbers are within specs, then when it's in the crank but no start mode, are there no volts to the coil? That would prevent it from starting. When it's in the crank but no start mode are there volts to the coil but no trigger signal? That would also prevent a start. The PCM MUST receive a valid signal from both the crank & cam position sensors or it will not send a signal to the coil. Both can be tested, & both are relatively easy to change, but assuming those are both good I am thinking that this now kind of points to the PCM.
 

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A bad crank sensor or distributor pickup would also cause the coil not to fire even with a known good coil. And as far as having the distributor "bench checked...

these aren't the days of points and advance weights that can go bad/stick
Nothing to "bench check" on these distributors. If the pick up under the cap is good the only other way they go bad is the toothed wheel that passes thru the pickup can come loose and wobble on its plastic base but that is very rare to happen. No need to pull out the distributor housing to figure out the issue.

I'm not convinced yet that it could be the ECM causing the problem yet.

If bet that had you not ever touched the fuel pump, all that you list that happened after you changed it would have still happened just the same. And with the backfire I'm still thinking base ignition including those 2 sensors possibly being bad.
 

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A bad crank sensor or distributor pickup would also cause the coil not to fire even with a known good coil. And as far as having the distributor "bench checked...
I believe it was mentioned in previous postS that the PCM must receive a valid signal from the crank & cam pos sensor or it would not send a trigger signal to the coil. Both sensors can be checked. But thanks, Captain Obvious.

If no flash: then check the operation of the cam position sensor & the crank position sensor.

If those sensors test good: send the PCM out to be diagnosed."
But if my coil ohmed out within specs, before I threw another coil at it, I'd probably be inclined to check & see if I was getting volts & a trigger signal to said coil.. And with a '98 you could probably consider the cam & crank pos sensors as almost part of the base ignition.

That would also prevent a start. The PCM MUST receive a valid signal from both the crank & cam position sensors or it will not send a signal to the coil. Both can be tested, & both are relatively easy to change, but assuming those are both good I am thinking that this now kind of points to the PCM.
 

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There are two easy checks that can be made at the wires to the coil with a MM & a test light -- for battery voltage through the ASD relay (which is also energized & de-energized via the PCM) & for trigger signal while cranking. I believe it was also insinuated in previous postS that if changing the crank & cam pos sensors did not rectify no trigger signal to coil that kind of leaves the PCM.
 

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My 98 Dakota was doing the same thing. After a few minutes of running it would begin to misfire and give me multiple misfire codes. I purchased a high energy coil from fleabay and haven’t had a problem since. Hopefully yours will be that simple.
 
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