1995Dodge Dakota 3.9L crank no start with spark! - completely stumped
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1995Dodge Dakota 3.9L crank no start with spark! - completely stumped
Hi All,
Been a long time reader of the forum, but never made an account until today as I am absolutely stumped and have no clue what to do.
I have a 1995 Dodge Dakota WS long bed 2wd with the 3.9l that has just shy of 200k miles and has been in the family since new. love it dearly, as it is simple, low, with a long bed and super smooth on the road. In early December, went into the garage to start her, and she popped once and then just cranked with no activity afterwards. I went through all of the following as I had spark, but it was kind of weak
After changing/testing those pieces, I was convinced I had spark (albeit weak) and fuel (could hear the pump and could squirt fuel out of the valve on the rail) so it must be timing. Given the PCM was replaced (junkyard unit) and the rotor pointing to the #1 wire terminal at TDC, I went for the time chaining thinking it must have jumped a tooth when it popped once in the garage resulting in the timing being off enough for it to no longer run with spark and fuel. When I opened up the case, timing chain was aligned but a bit sloppy after 200k so I replaced it and put it back together. Once it was back together, I went back to swapping the relays around, just in case and to be super methodical in verifying they were all good. I was using the starter circuit to test them. When cranking, I turned the key fully off but the starter kept cranking so I pulled the battery lead off of the battery. Ah ha! Must be a faulty key switch (had a key switch ignition issue on a much older vehicle that was equally as miserable to diagnose) So I replaced the key switch and viola! She fired right back up!! Only took three weeks of random tinkering but I had got it, on Christmas Eve to boot! A true Christmas miracle!
Buttoned her back up and it was smooth sailing from there!!! Purred like a kitten and rode like a dream......
Until last Wednesday. Same thing happened, went to the garage, hit the key, popped once and then just crank crank crank with nothing.
So, checked the usual suspects.... Again
The only difference this time, is I can get it to pop sequentially and almost run (pop pop pop pop pop and then stops after I get off the key) after cranking for a while and messing with the throttle (seems like it is most happy with the pedal 3/4 of the way to the floor, but this could just be me going bananas and loopy at this point).
What's left?? What am I missing?? I haven't touched the throttle position sensor as it was replaced already and from my understanding it should run with a bad one, just poorly. Same with the map sensor and the plunger thingy on the back of throttle body. Any insight/thoughts/feedback or moral support that you could provide would be greatly appreciated before I go completely mad!!
Been a long time reader of the forum, but never made an account until today as I am absolutely stumped and have no clue what to do.
I have a 1995 Dodge Dakota WS long bed 2wd with the 3.9l that has just shy of 200k miles and has been in the family since new. love it dearly, as it is simple, low, with a long bed and super smooth on the road. In early December, went into the garage to start her, and she popped once and then just cranked with no activity afterwards. I went through all of the following as I had spark, but it was kind of weak
- Relays in the fuse box
- Splice under the fuse box
- Crank sensor (replaced)
- Distributor sensor (replaced)
- Coil (replaced)
- PCM
- Cap/rotor - didn't replace as they are relatively new, but did a visual inspection to verify the contacts weren't green and fuzzy (they look new)
- Error codes - nothing
- Pulled the EGR thing on the back of the block as I read someone on here had an issue with it choking out the engine after running for a couple of seconds. Cleaned it and reassembled
- Throttle position sensor (best I can tell, it should fire with a bad one, but just run like garbage) replaced anyway due to lack of options
After changing/testing those pieces, I was convinced I had spark (albeit weak) and fuel (could hear the pump and could squirt fuel out of the valve on the rail) so it must be timing. Given the PCM was replaced (junkyard unit) and the rotor pointing to the #1 wire terminal at TDC, I went for the time chaining thinking it must have jumped a tooth when it popped once in the garage resulting in the timing being off enough for it to no longer run with spark and fuel. When I opened up the case, timing chain was aligned but a bit sloppy after 200k so I replaced it and put it back together. Once it was back together, I went back to swapping the relays around, just in case and to be super methodical in verifying they were all good. I was using the starter circuit to test them. When cranking, I turned the key fully off but the starter kept cranking so I pulled the battery lead off of the battery. Ah ha! Must be a faulty key switch (had a key switch ignition issue on a much older vehicle that was equally as miserable to diagnose) So I replaced the key switch and viola! She fired right back up!! Only took three weeks of random tinkering but I had got it, on Christmas Eve to boot! A true Christmas miracle!
Buttoned her back up and it was smooth sailing from there!!! Purred like a kitten and rode like a dream......Until last Wednesday. Same thing happened, went to the garage, hit the key, popped once and then just crank crank crank with nothing.
So, checked the usual suspects.... Again
- Swap all the relays around, looking good there
- Swapped in the junkyard PCM I had on the shelf from last time (I had put my old PCM back in after swapping in the junkyard PCM with no luck) - no difference
- Checked the spark, nice and strong
- Fuel pressure checked at the rail
- Injectors - checked with a noid light thingy, all good
- Unplugged the crank sensor and distributor sensor to verify that the spark dies if these are not operational (they are three months old too)
- Shook the harness anywhere I can get my grubby hands on it followed by hitting the key -nothing
- Pulled the timing light out and verified I have spark at TDC on 1 (confirmed) as I feel like this might be timing related if I have good spark and fuel - uggghh
The only difference this time, is I can get it to pop sequentially and almost run (pop pop pop pop pop and then stops after I get off the key) after cranking for a while and messing with the throttle (seems like it is most happy with the pedal 3/4 of the way to the floor, but this could just be me going bananas and loopy at this point).
What's left?? What am I missing?? I haven't touched the throttle position sensor as it was replaced already and from my understanding it should run with a bad one, just poorly. Same with the map sensor and the plunger thingy on the back of throttle body. Any insight/thoughts/feedback or moral support that you could provide would be greatly appreciated before I go completely mad!!
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My ideas are Check the pressure from the fuel pump to be sure it is steady and possibly the intake air temperature sensor. But the key switch being the fix last time makes me doubt. Could it be the new switch failed?
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So, yes, I did replace the key switch again with the no difference. I pulled the IAT as suggested and cleaned it since it was pretty dirty (had to look it up, never even realized it was hiding there). I have to read tonight on if it can be tested with the multimeter. Today, based on the starter fluid comment, I gave it try but it didn't seem to do much, still would pop pop pop and the quit once I got off the key. I was getting a bit frustrated, and given it seems fuel/mixture related, so I cranked for a long time, pumping the accelerator while doing it, and after 20 seconds or so of cranking with the pedal on floor, it stumbled to life. I slowly backed off the accelerator once it was running and it settled into an idle. I let it idle for a while and it seems like it might be missing on one cylinder, definitely not idling as smooth as she used to. Is this indicative of a bad map, IAT or something else?? I was able to get a normal rpm increase when depressing the pedal after letting it idle for a bit.
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So, yes, I did replace the key switch again with the no difference. I pulled the IAT as suggested and cleaned it since it was pretty dirty (had to look it up, never even realized it was hiding there). I have to read tonight on if it can be tested with the multimeter. Today, based on the starter fluid comment, I gave it try but it didn't seem to do much, still would pop pop pop and the quit once I got off the key. I was getting a bit frustrated, and given it seems fuel/mixture related, so I cranked for a long time, pumping the accelerator while doing it, and after 20 seconds or so of cranking with the pedal on floor, it stumbled to life. I slowly backed off the accelerator once it was running and it settled into an idle. I let it idle for a while and it seems like it might be missing on one cylinder, definitely not idling as smooth as she used to. Is this indicative of a bad map, IAT or something else?? I was able to get a normal rpm increase when depressing the pedal after letting it idle for a bit.
I had another thought reading this post, fuel synchronization. The distributor doesn't set the timing the computer does that. The distributor is how you set the fuel sync which is when the injectors fire in the cycle. I;m not sure it would be it ssince your original probem was the ignition switch. You need a, OBD1 Snap On scanner (MT2500) or some after market program to read the system while you set it.
There is a manual way.
These instructions are from another dodge site a guy named Larry. Where he makes mention of putting it in neutral, he is referring to a manual trans not an automatic. Pasted below.
I deleted the instructions I found the link to this one which also describes changing out the distributor. I can't get my machine to let me copy and paste my pdf of this page.
http://hughesengines.clients.nharmon...ons/DistRR.pdf
Last edited by onemore94dak; Mar 19, 2026 at 04:19 PM.
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Sorry for going MIA, I failed to give everyone here a proper thank you! Since that rough start and IAT cleaning/replacement she has been running great! The plugs/wires probably have 20k or so on them at this point. I have keep the fuel sync article as a reference in the event this happens again the future. To be frank, not really sure what I fixed this time around and am a bit nervous this problem might pop up again. Glad she is running (for now!) Thank you so much for your help and advice!