Van stalls only after heated up

[Meechigan Man]

I have a 93 Villager that has ran perfect until recently. It runs fine until it is driven and completely warmed up. When coasting or stopped (while in drive) it will occasionaly stall. I have changed plugs, wires, cap and rotor, air filter, fuel filter, and poured a can of sea foam (still have not used much gas since though). It idles at around 750. My next step is to clean the IAC, and maybe change the TPS, I'm leaning toward a TPS problem but would hate to spend $ if it's not the problem.
One thing that keeps bugging me is this only started happening after I changed batteries. I put a new one in (my garden tractor needed one and it fit better), and my wife told me of the problem, so I swapped it back thinking maybe the battery was a maybe tad too small. Problem didn't go away, I figured there was alot of corrsosion and maybe when I loosened it, some powder had gotten to where the sleeve contacts when tightened. So, I thoroughly cleaned everything, and still had problem.
It starts great, and does not seem to improve with all the accessories turned off, so logically I do not see how this battery deal could have started these problems. It's just such a coincedence, I really have a hard time completely ruling it out. One thought is, once it is warm, the fan will have to kick on putting more strain on the electrical system. ?? This puts an additional strain on the engine.
I have and still will continue to try and change out things, but can anybody tell me if I'm just an idiot for thinking this could be an electrical issue? Any comments would be greatly appreciated.

[tempfixit]

Welcome to AF.

Have you checked for codes??

How many miles??

I don't think it is the TPS. When you replaced cap and rotor did you look at the optical sensor in the distributor?? (CMP) I read on another forum about the very same problem you are having and they blew the dust off the optical sensor and has worked fine since.

Look in the online service manual sticky for the FSM site, it has all the procedures for testing TPS and getting codes.

Send you a PM.

Hope this helps

[Meechigan Man]

Thanks for the welcome, this is an excellent resource.

I have not checked for codes, the check engine light hasn't came on.

150k miles

I'll definately check the optical sensor, and go from there too, but I know it needs some good cleaning on the air intake side.

Last night I removed the air cleaner outlet tube. I found a small line that connects to it underneath. It had a big crack and was barley hanging on, so I fixed that. The bottom half of the mass airflow screen had a pretty good build-up. I dipped the mass airflow sensor in some Sea Foam, and it loosened up a slight bit of gunk, I still need to get some spray to blast it. I cleaned up everything and put it back.
The throttle body had a slight dark gunk around the plate, I have to clean that for sure, I plan on just blasting it with spray. Or, should I try and remove it and soak, I imagine I will need a gasket too. Do I risk throwing anything out of adjustment? Any suggestions would be great but, in the meantime I'll search the online service manual.
Also, would sucking in Sea Foam through the brake booster vacuum line clean the throttle body? I suspect it wouldn't even touch that area.

[tempfixit]

Originally Posted by Meechigan Man

Thanks for the welcome, this is an excellent resource.

I have not checked for codes, the check engine light hasn't came on.

150k miles

I'll definately check the optical sensor, and go from there too, but I know it needs some good cleaning on the air intake side.

Last night I removed the air cleaner outlet tube. I found a small line that connects to it underneath. It had a big crack and was barley hanging on, so I fixed that. The bottom half of the mass airflow screen had a pretty good build-up. I dipped the mass airflow sensor in some Sea Foam, and it loosened up a slight bit of gunk, I still need to get some spray to blast it. I cleaned up everything and put it back.
The throttle body had a slight dark gunk around the plate, I have to clean that for sure, I plan on just blasting it with spray. Or, should I try and remove it and soak, I imagine I will need a gasket too. Do I risk throwing anything out of adjustment? Any suggestions would be great but, in the meantime I'll search the online service manual.
Also, would sucking in Sea Foam through the brake booster vacuum line clean the throttle body? I suspect it wouldn't even touch that area.

The CMP normally does not throw a code.

I would get some MAF sensor cleaner in a can from parts store or maybe Wal Mart handles it to spray the MAF. Do you see the air filter element when the filter housing is all in place??? This can contribute to the MAF being contaminated. Fix for that is get yourself a 7" long bolt with a locking nut, drill a hole about 1 1/2" from top of lower filter housing base and tighten bolt to remove the curvature in the base housing until everything fits together properly.

To clean the throttle body I just used some throttle body cleaner in a can, sprayed the throttle body and take a old tooth brush,scrub the plate and surrounding area then spray lightly again and remove carbon with a suitable shop towel. (Be careful not to spray to much into the plenium, excessive amount of sprayed cleaner will fill the #6 clyinder and stop the engine from cranking when trying to start. I learned the hard way)

I don't know about the use of Seafoam as I have never used it.

Did you get my PM???

[Meechigan Man]

That sounds easy enough for cleaning. The filter housing looks pretty straight, but I will take another close look. I need to to do that and clean the optical sensor for now...upon reading up more I'm pretty sure the bearing for the distributor is bad. I can hear and feel a vibration coming from it. Not sure if this is causing the idle problem (I suspect a # of factors). The part is probably expensive. Do I risk throwing the timing off, by installing a new one?
Not to get too far off track on this thread, but I also plan on installing a new timing belt, tensioner, and water pump. I think I'm all set as far as some tricks, but any other input never hurts. My grandparents owned this, and I'm sure nothing has ever been done to it. The noise coming from this area has bugged me for a while, and the more I research this, the more I realize I've been living on borrowed time.
Not looking forward to this, but I'm kinda excited to see if that will quiet things down. The satisfaction of doing these things on my own is awsome.

I did get your PM, thanks. Work is a little busy but I plan on getting signed up over there as well.

[tempfixit]

If you are hearing noises from your distributor changes are that you have bearing dust on the optical sensor. The distributors are expensive, check ebay for one. When you change distibutor set #1 on TDC before you remove and mark the old dist. for references just makes life easier. You will need to check timing with a timing light.

Regarding changing the timing belt and water pump you will need these tools.
1/4" rachect, short extension and metric sockets (if handy shalliow and deep sockets each work better in seperate instances. I believe 10mm but not positive)
Metric 10mm wrench (Again not positive of sizes but will need some wrenches)
Hopefully you have a air compressor and impact wrench to remove the Cranshaft bolt (harmonic balancer) if not you could try using a large rubber filter like wrench holding the crankshaft (harmonic balancer to break the crank bolt loose)
To remove the harmonic balancer you should be able to pull it off by hand but you may want to have a harmonic balancer puller on hand as a back up)

Once you get the crankshaft bolt removed set the engine to TDC on #1 and disconnect the battery.

Do yourself another favor if you get all the parts prior to starting and get both styles of timing belt and return the one you don't use. The reason is that the major population of the 93's used a like a square tooth belt but were changed to a different style belt I believe before the 94's came out, that way youre cover for parts.

Change your thermostat to at this time.

You will also need a good jack and jack stands because you need to remove passenger front tire to get access from the bottom.

Took me about 9 hours.

When you reinstall your coolant it works the best to have the front end of vehicle raised to burp the air out of the coolant system with the heater turned to highest level for both fan and heater.

You may already know some of this but I am just attempting to help and more than likely I have forgotten something.

[Meechigan Man]

Thanks for the tips on the timing belt, I didn't know that there's a possibility of having the newer timing belt.
I looked at the optical sensor and everything looked clean, I was going to blow some air on it anyway, but couldn't find the nozzle. So I just called it a night, it really did look clean.
I had to test drive it since it hasn't been driven since my latest findings. It didn't stall, but surged when coasting, up and down about 100 rpm. The wife drove it around quite a bit the next day and said it was running great with no stalls. I drove it later and didn't really notice any surge, though it was just in regular traffic where I couldn't really mess with it. I'm thinking everything I've done helped, but the sea foam needed to run it's course too.
I still want to have it suck in some sea foam and clean everything out, but for now it's running ok. Next will be the timing belt and all the other stuff that might as well be replaced...I'm hoping for some warmer weather soon.

Thanks for the help