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Dodge Grand Caravan, Dodge Caravan, Engine, Van
#1 of 12 1990 Grand Caravan stalls
Oct 02, 2003 (2:19 pm)
I need help! I am at wits end on my caravan. My van stalls, at 1st it was a few times a month & it would restart with no problem. Now it wont make it all of the way out of my driveway. I have taken it to several shops and have also had home mechanic work done but no one can figure out what the problem is. BTW, it's a 1990 Dodge Grand Caravan 3.3 liter V6.
In the last month I have had several diagnostics run on it but nothing is stored in the computer. I have replaced:
battery terminals & cables
automatic idle speed motor
Fuel pump works & fuel pressure is normal, charging system comes up normal, no shorts have been found, passed compression test, all cylinders/pistons/spark plugs & wires fire normal.
I don't know what else to check & I'm close to running out of time/patience & money. ANY help or suggestions would be appreciated. Thanks
#2 of 12 Clean the throttle body
Oct 02, 2003 (3:11 pm)
Remove the air snorkel, have somebody hold the throttle wide open for you. Now get a can of spray carb cleaner and an old tooth brush. Scrub the entire inside surface of the throttle plate and spray it all of with carb cleaner. Restart the engine, hold the RPM's up for a minute to clear out all the junk sprayed in there. Now slowly bring it to idle so it can re-learn idle speed.
This is the most common problem for that symptom but it could always be a number of other things like IAC, TPS or a serious vacuum leak. Try the cleaning and see what happens.
Oct 02, 2003 (4:19 pm)
Thanks desi for the advice but I guess I left out a few things that have been done to the van (I've done so much that it's getting hard to remember :-/ ), for instance I have adjusted and cleaned the throttle body & the cables. I am positive that I have no vacuum leaks and the idle runs at normal. I did forget to throw in there that just before it stalls the tach goes berserk! It starts wildly jumping up & down then buries itself at zero, which is the only way I even know that the van has stalled other then trying to turn & realizing that the power steering pump suddenly has no power. That just reminded me of another thing that has been replaced..the fusible link on the positive battery cable & the battery itself.
I spent the day at this web site reading on the Caravan and after reading a few other entries I'm beginning to wonder if the ac compressor is playing a part in the stalling ?? I have read that other then the tranny people seem to have problems with brakes & ac..which I have had no problem with to date. I run my ac 24/7...even most winter days ( I live in sunny California ) and it runs ice cold.....hmmm
Thanks for any & all input
#4 of 12 Other posibilities
Oct 03, 2003 (4:51 am)
for instance I have adjusted and cleaned the throttle body & the cables.
I don't know exactly what you meant by adjusting the throttle body but if you mess with that base idle screw, I hope you know how to do it. It's a pretty technical adjustment.
Now you say the tach goes screwy. That is an indication of losing you primary ignition signal. I don't know the the details of you engine (dist..DIS..etc),. also, we don't know if we are also losing injector pulse or not. In order to find out the van will have to be run with a spark tester and a noid like attached and observed when the stall occurs. This knowledge will point you in the right direction. An ignition only loss would point toward coil or ignition module. If injector pulse is dropping also look at things like crank sensor (DIS) or dist pick up (dist engines). They supply reference for both. Sometimes the ECM supplies power supply to both coil and injectors. This could also be an issue. Monitoring fuel pressure would also be a good idea. Bottom line is you have many possibilities and you need to gather a lot more symptom info.
Oct 03, 2003 (6:40 am)
Thank you very desi for the added information.
for instance I have adjusted and cleaned the throttle body & the cables
What I had meant by that is that the throttle cable had come loose so I had that adjust (yes with the base idle screw) & I had the throttle body itself cleaned with cleaner & brush to make sure it wasn't sticking.
As for the engine itself it is DIS and I have had the fuel pressure checked but while idling not as it stalled so I will have that checked again, thank you. Also I had the coil checked but again not as it stalled, only during as it idled so I will have that checked will it idles until it has actually stalled to see if that reading comes up different. 1 mechanic I took it to suggested that it might be the ignition switch but he said that there is no way to check it, I would need to replace it & then see if it helped. It had sounded to me like he was just trying to take more of my money.
Thanks desi I will try what you have suggested.
#6 of 12 tough to diagnose
Oct 04, 2003 (9:41 am)
I would need to replace it & then see if it helped. It had sounded to me like he was just trying to take more of my money.
That is what we refer to as "throwing parts at it" Believe me, a good tech doesn't operate that way. This is what makes it so hard with intermittent problems. You HAVE to duplicate the problem and it has to be when you are monitoring the vitals so you see what gave out first. I deal with problems like this every day and it's tough. You can't guess, you HAVE to confirm what's actually happening. That's why I said to monitor spark, injector pulse and fuel pressure. You have to know what every one did as it stalled. Everything will test good if the problem is not occuring.
Back to that base idle statement.
If you really did mess with the base idle screw, it could be a lot of you problem. That is a critical adjustment and has to be set exactly as the instructions say. If that is set incorrectly, it will cause the idle controls to get totally confused and either stall or "hunt". You should NEVER touch the base idle screw on a computer controlled car. It is NOT for idle speed.
Oct 04, 2003 (7:00 pm)
When I said "I" adjusted the idle screw I didn't mean me personally, I do not know THAT much about cars, if I did I would have already been able to diagnose the problem & fix it. A mechanic friend of mine that owns his own shop did it for me. He can only do so much for free though when he's got paying customers waiting so I only take it to him when I'm desperate. By desperate I mean after taking it to several shops that would give me a line like, 'you can't check the ignition switch you just have to replace it & see if it fixes the problem'. That kind of desperate. That it what brought me to this web site, mechanics see a female walk into a shop saying my car stalls, can you fix it? & they're ALL over that! I don't trust a single 1 that I have run across yet, not even the dealer's mechanics who told me to replace the AIS motor & that would take care of the problem when he hadn't even seen the car, just talked to me over the phone! The reason why the idle screw was tightened up is because the cable was extremely loose and though that didn't not help the stalling problem it hasn't caused a problem so far either, the problem was already there before that screw was ever messed with.
You said that the base idle screw was not for idle speed but you did not say what it was for...now I must admit that you've peaked my curiousity..lol
#8 of 12 Base Idle
Oct 05, 2003 (8:25 am)
The base idle screw sets a minimum parameter for the IAC to take over. The idle is actually controlled buy the computer by controlling and air bleed that bypasses the throttle plate. If that screw is set higher than it should be then the computer controls just keep hunting all over trying to find the correct RPM that the screw is preventing it from finding. I don't believe the throttle cable is adjustable at all so all you can do there is damage. In order to set base idle, the computer has to be disabled while some other protocols may also have to be met. Every car is different.
One thing to look for if you suspect the ignition switch is to watch for dash gauges and accessories to die at the same time. If your accessories and lights stay on, it's not likely the ignition switch. It may be a little more complicated than your going to be able to handle.
#10 of 12 Dodge Caravan stalls
Oct 26, 2003 (11:05 pm)
Well, I was finally able to get the van down to the shop and they ran a full diagnosis on it. Even though it stalled on them while hooked up to all of their equipment they could find nothing wrong with it. Everything passed with flying colors..? Now I am even more at a loss then I was before as to what to do with this vehicle next.