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Sun May 29, 2005 6:49 pm

Ok the van misses at idle, when warm. Its not that obvious you really have to listen for it but its there :x .

What Ive done so far:
Fuel pressure 29 (35 when reg. hose pulled), timing set, idle set, fuel filter checked( little sand/junk), plugs gapped, no vaccuum leaks ( needle fluctuates rapidly between 18 and 21), valves adjusted, no points / electronic ignition (phased correctly).
Have not done : compresssion test, hope to do this in the next couple of days after I borrow tester from brother-in-law.

Other than the miss the van runs great. Good power/acceleration but still crappy MPG. Besides the comp. test what else should I do or look for.

Sun May 29, 2005 6:55 pm

Oops, forgot to mention that I have replace the temp sensorII.

Sun May 29, 2005 6:55 pm

we talking about an air cooled?

Sun May 29, 2005 6:56 pm

Yes, 82 westy......

Sun May 29, 2005 7:03 pm

Assuming your vacuum gauge is properly "T"ed into the manifold vacuum line (I would use the line coming from the air plenum to the fuel pressure regulator), I would assume that the problem is in an improperly adjusted valve, a vacuum leak, or a worn valve guide.

When did you last adjust the hydraulic lifters on this thing? Try going to one turn past contact.

http://www.s10blazers.com/vacuumtest.htm

Then do the compression test with a nice warm engine. Do the oil squirt after the first test. Write down all of the numbers and let us look at them.

Sun May 29, 2005 7:15 pm

Well I did the valves today and they are 1 turn past. The vaccuum guage is "t"ed exactly there. Ive also looked at all those sites you had put in previous post (great sites, now in my favs) and Im thinking valve guides. I am also assuming that the comp. test will show this, right? :?

Sun May 29, 2005 7:56 pm

Does she burn a bit blue when you first fire it up? That is usually a worn guide sign.

Make sure you do the test without and then with the shot of oil. Make sure the engine is warm when you do it.

The bottomen of these motors are pretty much bulletproof, so doing a valve job would not be the end of the world.

Mon May 30, 2005 2:46 pm

Ok and the results are in...... =D> =D> (for comp. test that is)

1 : dry - 130 wet- 130
2 : dry - 150 wet - 160 ( bit high right? :? )
3 : dry - 145 wet - 145
4 : dry - 125 wet - 130

These numbers seem high to me considering the van has 151k on it. NOt sure what the PO's had done to it. Last PO said something had been done with the valves but he didnt know what ( from his last PO, original owner). So guys and gals what do you think?

ps: the engine becomes a mess when you spill a beer all over it! :wink:

Mon May 30, 2005 3:46 pm

Remember, carbon, altho rare on 1 cylinder is often the cause of higher comp..

Tue May 31, 2005 5:33 am

I think I may have done the test wrong. I was alone performing the test so i could not see the gauge. I just turned it over until i heard about 13 compressions. Can you pump the tester up to much? I think tonight I will do it again while looking at guage.

Wed Jun 01, 2005 6:29 pm

If there is carbon builde up what is the best way to remove it? These reading dont really explain my miss at idle do they? So what is the next move? :x

Wed Jun 01, 2005 7:13 pm

Well it might be that due to the variation of the PSI in the cylinders, the engine may be running a little lopsided, more than missing.

I thing you have replaced or checked about everything. Are the wires pretty fresh? This does not have an idle stabilizer or O2 sensor does it?
Have you done the Bentley test of the AFM with your volt ohm meter? Wires nice and tight from the top of the starter to the double relay?

When the oil injection does not bring up the compression by more than 10 psi, one can suspect the heads. The addition of the oil didn't do much so I would assume that the rings are in good shape. A leak down test can be done to see exactly what is leaking and where. I paid $75 for my leakdown tester and a shop will do it for about $50 or so, but I am not so sure I would even do that. I would just save my money for a valve job.

My guess based on the compression test, the vacuum readings, assuming your AFM is good, and everything else that you might be needing a valve job in the future.

That is work though. Have to pull the engine, remove the heads, take them to somebody that remembers how to do a good job on them and re-install. The plus side its that it allows you to do some other stuff that you can only do with the engne out. Check the front and rear mains for any oil leaking and correct end play, clean up the engine, clean the engine compartment and perhaps some compartment painting. Good time to inspect the clutch and the heating system and even time to re-pack those CV joints that you have been meaning to get to.

If it were me, I would do that at the end of the camping season and I would call the twin cities VW club to see who down there does good head work. Adrian at "Headflo Masters" in LA would be my first choice, but that would be a few weeks of down time.

Well that is my 2 cents. I am out of "idears" as we day here in New England.

Thu Jun 02, 2005 5:42 am

Thanks again Randy for the advice. That is what I was thinking. This winter due a tear down. In the mean time could I adjust the #2 valves in one or so more turns to decrease the compression to equal the engine out or is that not recomended to adjust each different. I think aftrer I get my tires :x ( PITA) Ill be ready for some camping. Summer starts in 1 more week. No more loud, crazy kids for 3 months. :D :D :D :D

Sat Jun 04, 2005 4:26 am

Just re-posting question to get response.

Could I adjust the valve on only the #2 cylinder? It is at 1 turn now. I was thinking of trying 1 more turn ( 2 total) or even more if needed. I am correct in saying that turning them in will decrease the compression.

Sat Jun 04, 2005 5:46 am

Try adjusting it by 1/2 turn and redoing the compression test. See where that takes you. If it goes toward balancing them out, try another 1/2 turn and re-test.

Another alternative would be to put another 1/2 turn on all of them to see what that does. You really aren't adjusting the valves here, you are removing the slack from where the hydraulics start to do it.

If non of that helps, I would just drive it for 1500-3000 miles or so and then re-test it (since all of that is free). I would not worry that much about it.