loss of power/stuttering issue. Now no start.

[nathan@el]

My 1980 aircooled Vanagon started developing a problem about a month ago, where it would sometimes lose power and stutter while driving. It was also stalling out randomly when stopped. Usually it would restart okay, but this weekend it stalled out at a traffic light and would not restart at all. It cranks fine (new starter and battery), but just won't catch. I had to get the van towed back to my parking lot.

I tried adjusting the idle speed and the mixture, but if anything I think I made the problem worse. Could this type of running problem be attributed to the points? Timing? Possible fuel pump issue? Colin, as you might remember the van was having a seemingly similar problem before we switched the distributor over to the 49 state system. The current problem SEEMS the same to me (at least in terms of the way the van feels).

Also, I put on a new distributor cap, new rotor, new air filter, and I checked the spark plug wires, and they seem to be fine. I also checked for vacuum leaks, and didn't see anything weird. I'm stumped at this point, and I have to admit that I'm intimidated by the points so I haven't touched that yet. I'm hoping the wisdom of IAC can help me out! I'm planning on driving the Vanagon up to Tahoe in a month for a week, so I need to get it running again.

--Nathanael

[ruckman101]

Check to make sure the points do indeed have a gap. I've had two sets of points now that the little brown rider that rubs against the distributor shaft lobes has simply broken off. No gap, no run.


neal

[nathan@el]

Update: After letting the van sit for two days, I went out to work on it this afternoon and it fired right up. Drove it around for about half an hour and everything seemed pretty good. This was an intermittent problem in the past though, so no guarantee that anything is actually "better". Intermittent to me sounds like a potential wiring problem?

Also, forgive me for the dumb question, but which way do I turn the screw on the AFM to enrichen the mixture?

[Randy in Maine]

DO NOT TOUCH the FI until you confirm the points are at the correct dwell and the timing is perfect right on the money.

[Amskeptic]

Update: After letting the van sit for two days, I went out to work on it this afternoon and it fired right up. Drove it around for about half an hour and everything seemed pretty good. This was an intermittent problem in the past though, so no guarantee that anything is actually "better". Intermittent to me sounds like a potential wiring problem?

Also, forgive me for the dumb question, but which way do I turn the screw on the AFM to enrichen the mixture?

Thou Shalt Not Fear Thy Points.
Rotate engine with wrench until you see the points open to their maximum amount. A matchbook cover cardboard should slip in the gap (so should .016" feeler blade). A point gap deterioration does give you successively more difficult starts, but does NOT spontaneously recover like your engine apparently did. I lean towards grounds and TS II wiring connections.
Colin
(CCW leans mixture, and feel free, by the way to screw with the screw as long as you make a note of where it currently resides (count precisely down to where it seats, and bring back. Now you can play and always get back to "home". Remember our stoplight mixture test, pump brakes rapidly and lightly: if idle goes up - too rich, goes down noticeably - too lean)

[nathan@el]

Thanks for the help Colin. The more and more I think about this problem, the more I'm thinking bad ground somewhere. Remember how I was having starting problems the last time you were out here, and we removed and replaced my brand new starter? It definitely helped the situation, but I STILL have random starting problems, where I will turn the key and absolutely nothing will happen. There must be a bad ground somewhere still.

And, excuse my ignorance, but what is the TS II? I'll take a look at that as well. I hate to say it, but I've already screwed with the mixture, and although I have a pretty good idea of what the setting was initially, I didn't precisely mark it. But I don't think that's the issue anyway...

I'll try the stoplight brake test to see if the mixture is anywhere close to reasonable.

[nathan@el]

Update: I just checked the ground on the transmission to the frame, and it was covered in oil from a slight transmission leak (which is another thing we will have to look at in August by the way Colin). I was optimistic that this could be the problem, so I removed the ground and cleaned up the connections--unfortunately, it did not solve the problem (but it's still a good thing to do of course).

Are there any other major grounds to look at, and where might they be located? My deficient Haynes manual doesn't seem to tell me this information.

[TrollFromDownBelow]

TSII is the temperature sensor number two, it is located on top of the left cylinder head (it is on mine, but that may not be the stock location....). the sensor itself is nothing spectacular to look at .. it's about half the size of a .22 short bullet casing... but about the same diameter. It literally screws into the cylinder head. I had a similar symptom .... turned out to be the connector between the TSII and the wiring harness had gone bad...cut it out and replaced with a bullet connector, and all is good now.

EDIT: To Colin's point, go ahead and play with the settings, however, unlike Colin I do not have a photographic memory, so i marked the original location for the FI mixtures with a dab of white out.

[nathan@el]

TSII is the temperature sensor number two, it is located on top of the left cylinder head (it is on mine, but that may not be the stock location....). the sensor itself is nothing spectacular to look at .. it's about half the size of a .22 short bullet casing... but about the same diameter. It literally screws into the cylinder head. I had a similar symptom .... turned out to be the connector between the TSII and the wiring harness had gone bad...cut it out and replaced with a bullet connector, and all is good now.

Thanks so much for this information. It sounds like a definite possibility for my current problem. I'll have to take a look at the engine and see if I can find the TS II. I've had some wiring problems in the past (Colin can attest to the shoddy wiring in the engine compartment), so it would not surprise me at all of the wiring from the TS II is bad.

[Lanval]

N,

Having similar issues here, and presumably my Temp II sensor wiring is fine (since it was all recently checked).

I'll write up my issues in a different post, but perhaps we need a day of wiring checking.

I have a soldering iron and a garage, so maybe we can fix anything you see that looks iffy.

Mike

[nathan@el]

Having similar issues here, and presumably my Temp II sensor wiring is fine (since it was all recently checked).

I'll write up my issues in a different post, but perhaps we need a day of wiring checking.

Sounds like a good idea Michael. These intermittent problems are the worst ones to diagnose and fix! How is your Vanagon doing otherwise? Have you got it all back together?

[nathan@el]

Update:

I MAY have potentially solved the problem. I ordered a new TS II from Bus Depot, and was trying to figure out exactly where it was located on the engine so I could install the new one, and in the process of trying to figure this out, I noticed that the double relay on the left was not attached very well into its housing at all--in fact, I could easily see all of the pins and such. I immediately thought, "hmm, that probably can't be good", and I stuck it back in tight. I've only taken the van on about a 15 minute test drive so far, but I can say that as of now, the problem SEEMS to have disappeared. Would a loose double relay potentially cause the symptoms that I've been describing above? I'm optimistic that I've solved the problem, but also wary, since the van has had good days in the recent past where it was symptom free anyway...

And now, another question: Where the heck IS the TS II on the engine?! Even if I've solved the problem, I may as well install this new one anyway, since I've got it on hand and paid for it. Of course, my crappy Haynes manual (which is all I have, unfortunately) doesn't seem to say anything at all about the TS II. I thought that I found it on the left head area near the back of the engine (toward the back of the van), but when I consulted the Haynes, it seems to say that is an oil pressure switch? Also, it doesn't look quite like the TS II that I got from Bus Depot.

[Randy in Maine]

Use zip ties on the DR to hold those in nice and tight.

The TS II is normally located over by cylinder #3, but it may be over on cylinder #2. The reason being that replacement heads (usually from AMC) only make the left side head, so someone may have mounted it on the #2. No big deal. Black wire about 4" long that feeds into the wiring harness, sort of a 13mm nut holding it on there.

If you can make yours work, do it and keep the new one in your toolbox. You may need it later.

[nathan@el]

Thanks Randy! I would have never thought about using zip ties to hold the relays in tight, but it sounds like an excellent idea to me. What's weird is that I can't even imagine how the relay got loose to begin with. It's not like it's super loose in the socket, and it seems to be on there pretty tight to me now that I've pushed it in. I guess many miles of bumps and vibrations somehow managed to work it loose a little bit.

[Randy in Maine]

Do yourself a favor and before you zip tie it, clean the connections with some sand paper and make sure the slots (on the plastic piece) are all where they should be first.

The zip tie will just help keep it nice and tight on there.