Grand Caravan won't start sometimes

[draksig]

I hope someone can help me with this. I have a 94 grand caravan with a V6 engine. Recently I have been having problems with it. Driving down the street in town recently it quit on me but started right up. After I got home, it wouldn't crank. It would turn over but it wouldn't crank or even hit. I called a mechanie to tow it in for service but before he couold, I tried it again and it cranked right up. He still looked at it and could find nothing wrong. I drove it fro 4 days and one day after shopping, it wouldn't crank. same thing, it would turn over good but not fire up. 3 hours later I tried again and it cranked right up.

Anyoen else have this problem? The fuel pump was recently replaced but is working fine. No codes from the computer.

[yardboss]

Does this happen when it is wet or raining? Perhaps the distributor cap is cracked. There is a wire the runs from the distributor to the back of the engine. The end may have become exposed over time and needs to be re-seated.

[draksig]

Originally Posted by yardboss

Does this happen when it is wet or raining? Perhaps the distributor cap is cracked. There is a wire the runs from the distributor to the back of the engine. The end may have become exposed over time and needs to be re-seated.

Nope, not raining and not wet. IT just won't crank then later it will (at least for now. I'm sure that sooner or later it won't).

[Vernon Sieffert]

I have a 96 Caravan that is exhibiting similar problems in just the past 2 weeks. Between 2 and 10 minutes after initial start, the engine will quit momentarily. I have only noticed this after the vehicle has sat overnight in my driveway or at the end of the work day. In the past two days, it has failed to start on initial crank, but after several tries does start up. These symptons are intermittent right now.
When the vehicle wouldn't initially start, I pulled a plug wire off to see if I could isolate as electrical or fuel related. I had my neighbour crank the engine over while I checked for spark. Unfortunately, the engine started at that point.
Would appreciate if you check as well and post what you find out. The problem is becoming less intermittent, and am not looking forward to paying a tow bill.

[RIP]

Camshaft and crankshaft sensors are infamous for creating stalling and hard starting issues without generating a fault code as they are designed. At anytime while starting or running, if the engine computer doesn't see a good signal from them the engine will die or not start. The engine will still rotate/crank when you try to start it but, it won't run. This is only one of many possiblilities but, a likely culprit.

Suggest you connect a scanner and check for any codes the engine computer (PCM) may have stored. Autozone does it for free. No codes? If you find spark is missing and there's no power to the fuel injectors the auto shutdown relay may be denergized and most likely because a cam or crank sensor signal is missing. These sensors are less than $50. I've read they can be had for as little as $15, they are easy to change, and it's best to change both.

[draksig]

Thanks for the feedback. I checked the codes and found none. We believe that it must me a sensor of some sort but with the motor running, finding out which one it is will be hard.

Thankign about changing out the camshaft, crankshaft and mass airflow sensors.

[chubbygoatboy]

Any answers for sure yet?

I am trying to help out a friend. He has a 94 Caravan 3.0 as well. It for the last year or so, would randomly die, he would coast off the road, and it would always start right back up. This went on for a long time, then it actually went through a spell of two weeks of not happening, and running great.

Then about a week ago, it died in his driveway, and has not started since.

Here is what I found: Cranks just fine, but no gas or spark. Cannot find any bad fuses. If you jumper the fuel pump relay, you can hear it run. There is no voltage getting to the coil. The timing belt is farily new, and has not broken. The rotor still turns. My first thoughts are cam and crank sensors, but it appears as though there are not any on this engine.

ANY IDEAS?? THANKS

[webbch]

If when you check for fuel and spark and both are missing, this indicates the autoshutdown relay has been denergized and most likely because a cam or crank sensor signal is missing.

These are your symptoms. Check the B+ terminal on the coil - when you turn the ignition to the on position, you should get voltage here momentarily (like 1 second). When you start cranking you should get constant voltage here. If it passes the first test described, but fails the second, you can be pretty darn sure the automatic shutdown relay is activating due to lack of input from either the crank or cam position sensors.

[chubbygoatboy]

Thanks for the reply! But, I am fairly sure there are neither a cam or crank sensor on this. I cannot find them, and the autoparts stores do not show a listing. What you said makes perfect sense, but can you tell me where they are at? It is a 94 3.0 liter, it has a distributor on the right front corner of the engine, right on top of the end of the front head.

thanks

[webbch]

Oops, wrong application - you have a distributor an therefore probably don't have crank/cam sensors. I guess I was thinking of the distributorless 3.3 and 3.8 engines. Too much ASSuming on my part.

Does the vehicle at least have an automatic shutdown relay? If so, I'd check the factory service manual to see if it lists the conditions under which this relay gets energized (or de-engergized as the case may be). That's how I identified the test procedure for my van

[RogBed]

Here's something you can check as well that is simple. May or may not work, but hey if it does, you'll be happy.

My cousin had the same exact problem early in the week you are describing on his 94 caravan, 3.0 motor. He got it towed to a garage and they replaced the fuel pump & filter ($550 total, parts, labor & tow). He got the car home and it stalled out again, but started back up. He drove it all day yesterday and it seemed a little sluggish. It stalled out again and he couldn't get it to stay running for more than 7 or 8 seconds at a time. He called me and we spent a few hours trying to figure it out.

We checked all the wires, hoses & vacuum lines. Everything looked ok. I told him to move a wiring harness that came off of the distributor and went down to the bottom of the engine, because it looked liked it was too low and in danger of hitting a belt and pulley. He picked up the harness and noticed the wires were all exposed and had burn marks from the pulley on them. He placed it up high temporarily and seperated the wires some, so the bare wires weren't touching each other. Got back in the car and it started up without hesitation and ran strong. We shut off the engine a few more times and it started right up and ran strong each time again. We taped off each wire individually with electrical tape and used a tie wrap through an existing bracket to hold the entire cluster or harness up out of harms way. He called me minutes ago to tell me it was still running strong and how relieved he was.

Give it a shot. Check each wire carefully. At first, some of them looked fine, but upon closer examination, you could see bare wire (blackened by the belt obviously and probably shorting or arching out). Good luck!

[chubbygoatboy]

It does have the shutdown relay, so I will check that possiblity out. As far as the wires, I will check them as well, but I recently did the timing belt and I think I would have noticed that kind of a wiring issue, but I will certainly check it out. THANKS

[rhandwor]

Use a 12 volt test light the coil positive should light when cranking. Then go to the coil negative the test light should blink when cranking the engine. If it doesn't buy a new pickup for the distributor.
You can use starting fluid and spray in around the throttle body or in the intake remove the big hose. Don't spray the air flow meter.
If it starts you have a fuel problem.

[chubbygoatboy]

Well, there is no voltage getting to the coil, and the pickup was swapped with a known good one, and still no fire at all. Any more ideas? THANKS

[rhandwor]

You need a wiring diagram look at a Haynes manual. I think the voltage comes from the ignition switch to the coil but I'm not sure. It won't run until you have voltage to the coil.