I have recently come into ownership of a 1991 Dodge Dakota 4x4, 3.9L carbureted. 156K, former Dept. of Agriculture vehicle. Looks like ****, the white paint job is half peeled off (I wonder if it was a cheap aftermarket job to make it government white). But it's straight and otherwise seems in good condition. I have owned it for 5 days and it hasn't moved an inch from the guy's yard where I bought it.

No spark. Thought it was as simple as a coil. No. Thought it might be as simple as a pickup coil in the distributor. No. Thought it might be as simple as no fuel. No. Thought it might be the infamous 3-way splice in the wiring harness a little ways from the battery. No. Thinking it's a sensor or the computer, although according to the gentleman from whom I purchased said rig, the computer had been recently replaced. A big reason I'm here is for assistance diagnosing this no spark/no start issue. Hello and help.

 

3.9, carbureted, turns over nice and healthy, distributor spins, no spark at plug wires or from coil. Coil replaced with 2 others, all 3 tested good, no spark at any point. Distributor replaced with another (used) distributor in case pickup coil was bad, no change.

I've never owned a Dodge before, I'm wondering if it's a crank/cam position sensor, but I'm not sure the engine has one - haven't been able to spot one. Are there only cps' in fuel injected engines? Where is the bastard?

Other question: is there a reason NOT to run a wire from the battery positive to the coil? That's how I have my '84 Bronco going because the ignition broke. Granted the '84 is a simpler engine. two oh eight 659 71 three two, please text if you have the answer, I'll check back for replies tomorrow

heeeelp

thanks!

 

Are you sure it is carbureted? In 91 it would have been TBI Throttle Body Injection. Yes it could be a cam or crank sensor. First check the check engine codes.

 

Welcome to the site. I will move this thread to the first generation Dakota section,
FF

 

Welcome to the forum!

I don't see where you say you have replaced the wires. I had a similar problem two summers ago and it turned out to be my coil wire got to close to the exhaust manifold and melted the shielding thus causing a break in the carbon fiber. The engine would turn over all day long but it wasn't going to start.

 

hey i hate to say it but are ya sure ya checked "ALL" the splices in the wires running to the fuze block,,ya gotta unwrap the entire wireing harnes ..theres more than one splice that will cause your problem ,,and even if they aren't completly broken or corroded they still could be causeing your problem ,,i'd make sure all the splices are good before ya go investing in parts ya don't need ,,
crazy

 

Thats probably factory paint, my 1993 was factory white and it was great until one day it started flaking off in chunks the size of sheets of paper. Thankfully insurance covered it and the whole truck got a fresh new coat of paint.

In light of your problem though I would check the splices first as mentioned, in our older trucks this seems to be a very common problem, then I would do the wires, you can check your wires for resistance if you have a multimeter you should have a couple hundred Ohms per foot of wire but any bad wire will probably register as infinite resistance.

 

Your truck definitely doesn't have a carb but as stated before it has TBI injection. Those 2 round thing you see in the top of the throttle body are fuel injectors.

You have a crank position sensor on the back of the engine on the passenger side where the bell housing connects to the engine and the cam position sensor is inside the dist cap...the flat round disc with the 2 wires attached.

Crank Position Sensor


Cam Position Sensor

 

Thanks for the replies/assistance everyone. My mistake, I guess I do have toilet bowl injection. I put a different distributor in, so my cmps is effectually changed, I gather from bwdakrt's post. I still haven't found the ckps, I'll look again tomorrow.

However, my problem still appears to be no spark from the coil, so anything AFTER the coil is a secondary concern for me at this time. What I have done is run a wire from the +battery post to the +terminal on the coil, and another wire from the -terminal of the coil to the body, using the same ground point as the -bat. cable.

Tried starting it again, once with the wires as described and the original harness wires also connected to the terminals, and once with those DISconnected and only with my jimmy rigged wires. Still no spark either time, just a very hot coil. May have fried it, not sure if they get hot normally or no, I have 2 others though.

Am I wrong in thinking that wiring the coil thus should effectively bypass any bad sensors/computer wiring/etc? Seems to me that if I have a good coil so wired, and am getting fuel, the engine should fire. How it will run will be in question, but at this point I just want some sort of combustion!

Thanks to Dale from Missouri, btw, for your moral support and brainstorming. I don't wanna give up on this truck.

P.S: I am disconnecting the hot wire from the +battery terminal to the coil when not cranking the engine

 

Hello all, I am new here and need help pls. I am experiencing a similar problem with my 1991 Dodge Dakota 3.9 V6 described in this topic. The only difference is, my truck won't start if the ambient temp is 45F or colder (will turn over fine). Above 45F and it will start fine and run fine. If there was a break in the electrical or bad relay it wouldn't start at all.
The truck has 155k miles and in very good condition, Previous owner replaced the following:
coil, cap, rotor, pick-up coil, plugs, plug wires and ASD relay, checked fuses. no luck. (he was so mad he GAVE me the truck)

One thing I did notice, the ambient temp was warm and the truck started. I turned the truck off. I used the "KEY-ON, KEY-OFF" method to extract any codes in memory. The only codes were "12" (replaced battery) and "55" end of code cycle.
The next morning was very cold and thought I'd try starting the truck. Cranked over fine..... Well, no spark, no fuel = no start. OK, I'll try checking codes again. I noticed the "check engine light" or "maint. reqired" light wasn't showing at all when I turn the key on. So I left it alone most of the day until the ambient temp was warm. About 2:30pm I tried extracting codes again. This time the "check engine" and "maint. required" showed on the instrument, check engine light did it's thing for me with no new codes. and yes, the darn thing started right up! I tried this 3 days in a row. Cold morning=no start=no check engine light(with key on position). Warm afternoon=start right up=check engine light functioning(with key on position)
I'm in the dark on this one.
Thanks all
Peter