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Fri Sep 05, 2008 12:09 pm

Hello Samba denizens:

I'm having a troubling issue with my van. I hope you can help me with it.

I’ve got a 1986 GL Westy, 182K miles, original engine. The van is new to me as of January 2008. I am a rookie mechanic (Samba trained =^) but doing my best to learn.

Over the last few weeks I have (slowly) replaced all the fuel lines in the engine compartment, installed squeaky-clean fuel injectors from WitchHunter, added an auxiliary battery and rewired a few cabin items to run off of it, and replaced the blue coolant reservoir cap. I didn't operate the van for a few weeks, and prior to this time the van was running strong. I have not done a fuel system nor coolant system pressure check, but plan to soon at my local garage.

After these enhancements, the van starts fine and idles smoothly. After about 10 minutes of idling at 2K RPM, the stock temperature gauge has the needle exactly over the LED in the middle, right where it usually is. I can reach under the radiator and feel the coolant hoses; both are warm. I assume this means that both the thermostat and the water pump are operating properly. The coolant color is a nice florescent green. All appears normal from the front.

The problem: the engine is running very hot and has a noticeable lack of power. I do not have a laser thermometer, so I cannot tell you absolute temperatures. But after about 10 minutes of flat driving and then up a one mile hill in mild 65 degree weather, the rear bumper is very warm. I can barely hold the tab that swings out the license plate for more than a couple of seconds. The oil dipstick is too hot to pull out with my bare fingers. I can “smell” the heat from engine bay from the drivers seat, which never happened before. During this time, the temperature gauge on the dashboard remains right in the middle.

The van is has also lost significant power. The hill that it normally cruises in third now requires a downshift to second. I'm not feeling any surges or bucking, just a major lack of giddyup when I step on the gas. I know this engine can be a dog sometimes, but it is really underperforming.

So, any ideas what these problems might be?
Might I have screwed up something with the fuel injectors when I put them back in? (I am pretty darn sure the tiny O rings are in their proper place.)
Might a compression test help me out at all with the troubleshooting?

Your advice and comments are very much appreciated.

Fri Sep 05, 2008 1:28 pm

I know you replaced your coolant tank pressure cap, but I'm going to say it anyhow: when my coolant pressure cap went bad the first sign that something was wrong was when I tried to check the oil and the dipstick was so hot I couldn't touch it. I could also "smell" my engine because it was so hot.

I would suspect the cap and check it or replace it again. (I say this all the time on the Samba. And I'm usually right!) But would a cooling system problem cause the lack of power? Did you move the position of the distributor? If the timing is off it might affect performance and make the engine run hot, although that's not my first guess.

Fri Sep 05, 2008 1:29 pm

wow?

This is a tough one...any chance that the cat is plugged and heating up? This could possibly explain both problems.

I cant think of what else would make the tab on the rear door that hot, it almost seems like when it's hot feeling around and finding what is really hot and also where it's cool might help to locate the problem. Todd

Fri Sep 05, 2008 6:32 pm

It's funny, I usually don't think of the cat because I don't run one, but I agree with t, I would check that out.

Also, this isn't definitive, but it's easy to check: if the pressure cap is acting up you'll see the level in the rear filler tank changing a lot.

Sun Sep 07, 2008 8:50 am

I would still check the thermostat. Place it in a pan of water and watch it and see if it opens fully. I would also check the pump/alternator belt to see if it is got the proper tension. While your there, check and see if the water pump turns freely with the belt loose. Try and see if it drops the temp when you put the heaters on full blast (radiator bad if it does). The cat is a definite candidate for being suspect with your accumulated rear end heat. This could be due to being rich, now your injectors are doing their thing. Try replacing the Temp II as it may have started dumping a bunch of fuel and helping your cat go south. Then the other big suspect for sluggish operation is the good old Throttle Switch. Check that it is working correctly. You can simply unplug its connector and see if your power returns as well. Then adjust it properly.

Remove your cat and gaze through it, if it looks melted and/or the little tubes are blocked and you do not have a clear view through the stone, then it is toast. I have heard, but I do not condone (!) knocking the stone out with a chisel will give you a clear path for the exhaust. Ensure you remove your O2 sensor when this is done so as not to contaminate it. Even better, put a new one in, it will help bring the mixture back down as well. Check the wiring for a short as you do it. Make sure the ECU is unplugged when you check the wire for the short to get a true reading.

good luck.

Sun Sep 07, 2008 10:33 am

I had pretty much the same symptoms when my cat went bad.

Sun Sep 07, 2008 7:48 pm

climberjohn wrote: Hello Samba denizens:

I'm having a troubling issue with my van. . .

. . . I didn't operate the van for a few weeks, and prior to this time the van was running strong. . .

. . . The problem: the engine is running very hot and has a noticeable lack of power. . .

. . . The van is has also lost significant power. . .

. . . So, any ideas what these problems might be?

_____________________________________________________________

climberjohn,

Firstly, catalytic convertors don't usually queef out all of a sudden, but other things do. Before you do anything else, park the van in a really dark spot, dark enough that you can't see your hand held close to your face. Start the van and run it long enough to get it cooking, then, in the absolute darkness, fumble your way to the ass-end of the van and see if the cat is glowing a dark cherry red color.

If it is, the engine management system is fattening up the fuel mixture to the point that raw gas is reaching the cat and causing it to become more than a little exothermic.

Among other reasons, an excessively rich mixture can be caused by a bad ECU (unlikely), an OXS signal conductor which is shorted to its shield (which causes the engine to run like such a pig that it is likely unable to move the van) or a sick injector.

If an injector fails wide open, then, obviously, beaucoup fuel is going to be pumped into the cylinder. But, an injector passing NO fuel at all can provoke the engine management system into enrichening the mixture to the point that much unburned fuel reaches the cat. This is caused by the cylinder with the dead injector pumping only fresh air and diluting the exhaust seen by the OXS which, in turn, fools the engine management system into judging the mixture as too lean. The system tries to correct for the bogus lean mixture by enriching it to level where the mixture can't be fully burned. And, so, the cat gets hot enough to roast weenies over.

Richie

Sun Sep 07, 2008 7:59 pm

climberjohn wrote: Hello Samba denizens:

I'm having a troubling issue with my van. I hope you can help me with it.

I’ve got a 1986 GL Westy, 182K miles, original engine. The van is new to me as of January 2008. I am a rookie mechanic (Samba trained =^) but doing my best to learn.

Over the last few weeks I have (slowly) replaced all the fuel lines in the engine compartment, installed squeaky-clean fuel injectors from WitchHunter, added an auxiliary battery and rewired a few cabin items to run off of it, and replaced the blue coolant reservoir cap. I didn't operate the van for a few weeks, and prior to this time the van was running strong. I have not done a fuel system nor coolant system pressure check, but plan to soon at my local garage.

After these enhancements, the van starts fine and idles smoothly. After about 10 minutes of idling at 2K RPM, the stock temperature gauge has the needle exactly over the LED in the middle, right where it usually is. I can reach under the radiator and feel the coolant hoses; both are warm. I assume this means that both the thermostat and the water pump are operating properly. The coolant color is a nice florescent green. All appears normal from the front.

The problem: the engine is running very hot and has a noticeable lack of power. I do not have a laser thermometer, so I cannot tell you absolute temperatures. But after about 10 minutes of flat driving and then up a one mile hill in mild 65 degree weather, the rear bumper is very warm. I can barely hold the tab that swings out the license plate for more than a couple of seconds. The oil dipstick is too hot to pull out with my bare fingers. I can “smell” the heat from engine bay from the drivers seat, which never happened before. During this time, the temperature gauge on the dashboard remains right in the middle.

The van is has also lost significant power. The hill that it normally cruises in third now requires a downshift to second. I'm not feeling any surges or bucking, just a major lack of giddyup when I step on the gas. I know this engine can be a dog sometimes, but it is really underperforming.

So, any ideas what these problems might be?
Might I have screwed up something with the fuel injectors when I put them back in? (I am pretty darn sure the tiny O rings are in their proper place.)
Might a compression test help me out at all with the troubleshooting?

Your advice and comments are very much appreciated.

Easy... CAT is block

Ben

Tue Sep 23, 2008 2:15 pm

Okay Sambanistas, here's an update:

I removed the cat, hoping to find it would be damaged. It's in perfect shape, with honeycomb. (Repair records show the PO replaced it 4 years ago.) The muffler does not seem to be blocked in any way. Muffler and cat are now back on with new gaskets, copper nuts and lots of anti-seize.

It appears Rich's suggestion above is on the right track - an overly rich fuel mixture. Any other thoughts on where I can start hunting for the source of this problem?

Thanks,
Climberjohn

Tue Sep 23, 2008 2:25 pm

climberjohn wrote: The van is has also lost significant power. The hill that it normally cruises in third now requires a downshift to second. I'm not feeling any surges or bucking, just a major lack of giddyup when I step on the gas. I know this engine can be a dog sometimes, but it is really underperforming.

So, any ideas what these problems might be?
Might I have screwed up something with the fuel injectors when I put them back in? (I am pretty darn sure the tiny O rings are in their proper place.)

That's my vote. Either they aren't seated, sealed, connected, or one is not working correctly.

I believe there is a test in the Bentley / Haynes for your FI system.

Tue Sep 23, 2008 2:37 pm

I would do these checks. The Fuel Pressure Regulator Tests and the Throttle Switch Tests:

Here is a quick run down on what to do:

Tue Sep 23, 2008 3:37 pm

Climberjon,

I gotta ask, you ran it w/o the cat on right? you are not going to see a bunch of "damage" in the cat if it's plugged, the honeycomb will siply be plugged, or you can have a random broken piece that at times can plug the inlet/outlet to the cat. Thanks, Todd.

Wed Sep 24, 2008 12:43 am

Dog and Wasser: good tips, I'm on it in the next few days.

Todd: I did not run it with the cat off. I looked at it and it seemed in good shape, so I bolted it back on. In hindsight I should have driven it to help with troubleshooting.

I may well try your approach. With my new-found vast expertise on removing mufflers, I know I can now do it in 1/3 the time!

Thanks!
climberjohn