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Mon Jun 06, 2005 12:47 pm

I just acquired an 81 Vanagon with the original fuel injection. The van runs great when warmed up, and starts right up as long as the engine is warm. However, when the car has been sitting for 2-3 hours, it won't start, and smells like gas (flooding?). The only way I can get it to start is to lean out the mixture by removing the hose from the deceleration valve and or the air bypass valve and allow addtional air into the throttle body. I then have to turn over the starter a few times. I will then run for 3-4 seconds, and then stall out. After doing this about 4-5 times, I need to reconnect the hose from the deceleration valve. The car then starts right up and runs fine. Is this weird, or what??

I've checked the temp sensor 2, and it measures about 400 ohms at operating temp, and about 2000 to 2500 ohms at 68F, so that seems OK. I've unplugged the cold start valve so that it doesn't get a signal from the ECU, but that doesn't help. Maybe the cold start valve is leaking and causing the engine to run super rich? I've checked the air intake sensor, and that seems to be OK.

Anybody seen this problem? It only happens when the engine is cold (a relative term in Arizona, as cold is about 60F).

Mon Jun 06, 2005 12:56 pm

First off since it runs you need to get it running and check your timing. When was the last time it had a tune up? check the points, make sure the AFM flap isn't "sticking" or stick your finger in there and see if it moves freely, check this stuff first then get into the FI parts
do you have a Bentley manual?

Mon Jun 06, 2005 1:01 pm

I checked the timing, and it's OK. I have a Bentley manual, and it gives instructions for how to check individual components of the FI, but there are no "troubleshooting" guides. The points looked OK when I checked them a couple of days ago, but I'll check again. The thing that stumps me is that everything runs great once I get the car started, or when it's warm and I re-start it.

Mon Jun 06, 2005 1:31 pm

Try bypassing the fuel side of the cold start valve with some 7mm fuel line hose. If the gas smell goes away, your cold start valve is suspect.

Also have a look at the thermotime switch and do the bentley test on it.

While you are in there make sure the aux air regulator is all it is supposed to be.

Mon Jun 06, 2005 2:32 pm

Most likely suspect is a faulty thermo time switch. Second is an out of spec cylinder head temp sensor.

Mon Jun 06, 2005 6:19 pm

I got home this afternoon and re-checked the cylinder head temperature sensor (Temp sensor 2). When I disconnected the wire from the harness, as it says in the Bentley manual, BINGO.....open circuit (high resistance) from the sensor to ground. Bad sensor. The first time I checked it, I didn't disconnect the sensor from the wiring harness, and apparently measured the internal resistance of the ECU :oops: . I learned a valuable object lesson here. Follow the Bentley instructions exactly. If you do that, the fuel injection sytem is really not that difficult to troubleshoot :D . One of the reasons I bought this particular Vanagon was that it still had the original FI system and wasn't all hacked up. Keep it stock!

Mon Jun 06, 2005 6:21 pm

61 BUS wrote: I learned a valuable object lesson here. Follow the Bentley instructions exactly.

BADA BING! That's the BEST advice you can have right there.

Tue Jun 07, 2005 8:56 am

Good for you, keep tweeking it, I found the closer I got everything to specs. according to the Bentley the more power and pep it had. Even adjusting the CO on the AFM made a differance you could feel. I'm very happy with mine, and it only has one stock computer chip. :roll:

Sat Jun 11, 2005 8:24 pm

Had the exact same problem on my stock '79.

It was the head temp sensor. Replaced it and runs perfect.

Mon Jun 13, 2005 12:32 pm

Yeah, I got my head temp sensor over the weekend and dropped it in. It now starts and runs perfectly. Next item on my list is to install oil temp and pressure sensors and guages. It gets a little warm here in Tucson during the summer, and I want to make sure the Vanagon doesn't overheat, though I drive it pretty easy.

Mon Jun 13, 2005 1:21 pm

Can't beat that for a cheap fix can you? I keep a new one in my tool box for just such an occurance.

For gauges I would suggest at least having a cylinder head temp gauge. These seem to be the most accurate...

http://www.dakotadigital.com/index.cfm/page/ptype=...prd347.htm

Been here?

http://www.ratwell.com/technical/VDOGauges.html

Mon Jun 13, 2005 2:13 pm

Okay, not to start a heated debate, but I am ultra-curious now!! So, Randy, do use the Dakota brand for all of your gauges? That article seems to show that VDO's aren't what you want for any of the gauges. I want to get Mightyart in on this, if that's ok. What do you think Mightyart about the Dakota brand gauges? I am going to put gauges in my westy and I really would like to hear about which is going to be better between the VDO and Dakota's. Thanks fellas!!

Tue Jun 14, 2005 6:46 am

If your basically running stock and your engine is in good repair then VDO will tell you what you need to know. The Dakota gauges measure more accurate and cost more. If you like to tweak your engine and fine-tune it the Dakotas would be better. I have the VDO and won't be upgrading.
They do what I need them to do, tell me if something is starting to act different, or if I have a catastrophic failure. They run well enough that you can see a difference in the temperatures of the engine when the Temp outside changes. One thing I thought would be fun would be a duel CHT gauge for an ultralight they aren't that expensive.

Whichever brand you choose it is a matter of personal choice, both will do what you need.

Tue Jun 14, 2005 2:37 pm

Thanks Mightyart and Randy! I appreciate the info on that! So, about that dual CHT gauge, does it measure two cylinders instead of just the one? What brand is that one Mightyart? Thanks again guys!

Mon Jul 11, 2005 3:26 am

Here is a link to the Quad CHT gauge I'm installing in my Westy:

http://www.para-aviation.ca

Go to the StratoMaster Maxi-Singles page and look for the TC-2. Or if you really want to go to town, the TC-3 offers a 12-channel solution, so you could monitor CHT and EGT on all four cylinders and have four channels left over for measuring temperatures elsewhere on the engine.