Hello,

Coming here as my last resort as my 93 3.9 5Speed absolutely refuses to start, even after throwing $200 in suspected parts at it. I had the truck warming up idling a week ago for a good 20 minutes. I pulled it up the driveway, shut it off and went in the house. I came back out to leave about 5 minutes later and upon trying to leave, it kept stalling from idle. I thought it was just a fluke (in the past month there has been times that the truck will run "cammed" and barely stay running, but will fix itself in about a minute), so I figured I'd just start driving and see if it clears up. I only got about a block away before I came back, It wouldn't rev, and was missing bad. I got it home and it kept dying. I kept trying to restart it to the point where I killed the battery, as it just wouldn't start, only sputter.

Since then, during the past week it would rarely even sputter, only crank. I replaced the Plug Wires, Distributor Cap & Rotor, Ignition Coil, swapped around the ASD relay with some of the others, ripped apart the harness and found no bad splices under the fuse box. I also was lucky enough to find a 92 3.9 5speed ECU and popped it in (and later threw it when I was pissed) and it made no difference. Today I replaced the crank sensor and still only got cranking. I then realized that sometime during this week my tach went crazy and stuck off the scale. I then thought to replace the pickup coil in the distributor. I picked up a new pickup coil, which I found had the wrong connector, so I spliced the old connector onto the new pickup coil. Now since the wires are not labeled it's possible the outer two of the three wire cable are switched, but it seems correct as my tach now works again and the truck does TRY to start.

Now it sputters and coughs, and will get very close to starting, but will always die back down. It seems to get a routine going while cranking where it'll like my foot to the floor, then it'll die down and want me to let off the throttle and vice versa. Every time it does seem to be getting going, it dies back down.

The truck does have a very loud timing chain, but that didn't bother it for the last 178,000 Miles, and the rotor does still turn when the motor is cranked. It also burns some oil, and will SMOKE on startup after sitting for long periods of time.

I'm basically lost. If I push in the schrader valve on the fuel rail, fuel spurts out, I get spark from the coil, and down to the plugs.

I was considering having someone tow me to a hill and trying to give it a good pop start, but I'm not sure that it'd work. I don't know if the oil built up in the cylinders from sitting a week, or what. I cranked it over a half hour today in total, and never once got it to run on its own.


TLDR: Replaced:
Plug Wires
Cap & Rotor
Ignition Coil
Crank Sensor
Pickup Coil/Cam Sensor
ECU
Swapped relays for ASD
Checked Splice

Getting fuel to the fuel rail and spark to the plugs, but only sputtering.

 

[QUOTE=smith1090t;3375761 ... there has been times that the truck will run "cammed" and barely stay running ... The truck does have a very loud timing chain, but that didn't bother it for the last 178,000 Miles, and the rotor does still turn when the motor is cranked. It also burns some oil, and will SMOKE on startup after sitting for long periods of time.[/QUOTE]

Time to check the timing; not that you can change it on your year truck, but I bet the timing gear has jumped time, that will throw the distributor timing off (since it's run off the camshaft), and totally mess up the running of the truck.

If the timing IS off; I'd plan on a timing gear and chain set to get it back into time (try to not remove the distributor; if it was in sync, it should be close enough in sync with new gears).

HOPEFULLY nothing's had the "kiss of death"; these are supposed to be non-interference motors, but ...

RwP

 

Do you really think it could've jumped a tooth but the chain is still intact? I would've thought the chain would be massively messed over to have jumped a tooth, but I honestly don't know.

Is there any way I could check the timing without having to buy a light? And how will I know if it is off "too" far, as in, maybe my truck has been decently out of time all along because of the chain, how will I know if it got "worse"?

EDIT: And I think when it would run "cammed" that was a computer/ignition/fuel problem, not timing, because how could it only be intermittent if it was the timing chain, whouldn't it be all the time?

 

If the timing chain has stretched enough, you could have been having a problem with it shifting to right to wrong to right within its range.

The timing light is the quickest and non-intrusive way; the SUREST way is to pull the timing chain cover off and check there; however, if you've got the cover off, you might as well do the timing chain and gears ni there.

And yes, it can jump time without breaking the chain or the teeth; that's what my fiber gears did on my 1967 Mustang decades ago (back in the 80's). My replacements were steel; bad on me for using fiber on a new build! (Won't do THAT again!)

RwP

 

A bit of an update here.

Found out you were right a few days ago. I decided to do a compression test, tested three or four cylinders, got some around 60 PSI, and one at 0PSI. Put my borescope down two of the cylinders and found half circle dimples gouged into the pistons from the valves.

I still haven't totally made up my mind yet, but I'm half-heartedly moving toward swapping in a 318 at this point, but may abort and junk the truck at any time instead lol.

I guess my plan with a 318 is to keep my AX-15 and just swap the 318 right in, realizing (iirc) the flywheel from my v6 will bolt to the 318, and everything else should plug right in, with the exception of having to add 2 injector plugs. I also need a fan shroud from a 318 dak, but they are plentiful. Computers however, are not, and I was just lucky enough to get a first gen (93) 318 computer at the junkyard today, but it's from an automatic. I suppose now I'll have to find out a way to fool the computer into thinking the truck is in "park" for it to start when I get the 318, or will that computer not work for me at all?

 

Well, you'll need the V8 flywheel; there's only three cylinder marks on the V6 flywheel, and 4 on the V8 flywheel, for the crank position sensor to pick up on.

The ECU may work for now; it'll complain about the transmission and the upshift light won't work, but the engine should be enough to move you down the road.

While you're looking for the ECU, keep in mind the injectors changed in 1994; so you'll want a 92/93 ECU.

Also, the exhaust manifolds changed; so you'll want to keep a 92/93 set of manifolds, or pick up a 94/95 exhaust (at least the Y-pipe portion).

RwP

 

For the flywheel, I'm leaning toward just ordering a new one online, as they're only $100, but I'm not sure about clutches. If I'm right, I have a 9.5" now between my 3.9L and AX-15, but the flywheel for a 318 expects a 10.5" clutch? Does this mean I'll need to buy a 10.5" clutch? WIll a 10.5" work with my ax-15 and the slave cylinder and all?

I could always order a new ECU I suppose, but I am hoping my $20 junkyard ecu would work, vs ordering a $130 ECU. Don't care about the upshift light, it was burned out when I bought the truck (didn't even know it had one until I saw it when replacing bulbs in the instrument cluster), and when I replaced the bulbs in the cluster, I left it out.

This sounds like a slippery slope here with the injector and manifold stuff. You're saying if I get a motor that is 94-Current I'd need to swap in 92-93 Injectors? What about the injectors changed, just the plug, or the capacity? And as far as the manifolds go, I currently have the "big" 93 Y-Pipe then 3" straight back to a Flowmaster Super 10 with 2.5" duals. I'll want to keep that setup. Your saying I either need to put 92-93 318 Manifolds on whatever 318 I get, OR I need to get a newer Y pipe to match up to newer manifolds? Here's another question, are the manifolds the same from a dakota, to a ram, and a ram van? As in, can I (for instance) get a 95 Ram 318 with manifolds and Y-Pipe still attached, and just drop it in my truck, put 92-93 Injectors in it, connect my flowmaster to the Y pipe, put a 318 flywheel on it, and go? Oh and another question, I bought a new crank sensor and distributor pickup coil (cam sensor) for my V6 while trying to troubleshoot it, can I re-use them on my 318, or do I have to use a 318 sensors?

If I need to swap injectors to the 92-93 injectors if I get a newer motor, can I use the six I already have, and just find two more, or are 239 and 318 injectors different. And if I do swap to older injectors, do I need an older fuel rail as well?

Sorry about all the questions lol. I really do sincerely appreciate your help.

 

I can tell you that I have the 94 and what Chrysler did was shrink the size of the ports in the exhaust manifold and then the Y and pipe all the way back. I never bothered to find out if the connection ball/socket between the Y and the manifold changed sizes. Anyway I replaced my exhaust with the Walker Y and exhaust kit from Rock Auto and it is much larger diameter than what I had. The OE Y was 1.5" and the Walker is 2.5". Apparently up to 93 the OE exhaust was 3"

 

nothing within the computer to "trick" for auto vs stick.... only thing there would be if you were pulling an auto trans and putting a stick back in.... one small simple wire would need grounded..... and 2 connected to the stick trans backup switch for the lights.... but since youre starting with a stick truck and staying with a stick truck, youre good... I ran my 93 that was an auto originally that I put a stick into.... and it ran fine on the auto trans computer.

 

Well I am essentially going from auto to manual in the sense of the computer anyway. Since I am taking an auto computer and putting it in a manual truck. I'm starting with a v6 stick and ending up with a v8 stick, BUT with an auto v8 computer, so I need to ground that wire and connect the backup switch, which I'd appreciate more info on if you have any to offer.

In the end if using an auto computer with the manual trans is going to be too much of a hassle, I can always order a manual v8 computer, just trying to avoid the cost of doing so.