Bus is running REALLY rough...double relay the culprit?

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Thanks everyone for all of the help! I decided to check the electrical injector connection on 1 and discovered it was a bit loose. Then I noticed the fuel hose connection was loose. Then I discovered I still had an old hose on there (I thought I had changed out all the fuel lines)...then I discovered another old fuel hose. I think I might have started over there and never finished... :) So I'm rechecking all of the fuel hoses and replacing first. I also checked #1's spark plug, and it was very oil fouled. I put a new one in. I've also got some horrendously old and extremely stinky gas in the gas tank, so I'm draining it all out. I hope to get some progress done today. I also switched out #1's injector, as I just so happen to have a very clean spare engine sitting around...doesn't everyone? :) I wanted to see if switching the injector out would make #1 fire (along with the new spark plug)


Bret, I will check those grounds...and I know, we do need to get out camping! I'm committed to getting the bus on the road this year. It's been way too long.

[DjEep]

Make sure the female parts of the connections at the Fuel Injectors aren't pushed back in their sockets, they do that... And just to drill it home, grounds, grounds, grounds! I've had more injection problems related to that ground at the double relay or the three under the plenum than probably any actual faulty part.

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Well...I've made some progress. I drained all of the old gas (it looked like iced tea! ) and put some fresh gas. It seemed to run much better. I replaced the ignition coil (just because I happened to have a new Bosch one from my old parts bus) but it seemed to run the same. The last couple of weekends I've been driving it around the neighborhood, and it seemed really sluggish. So yesterday I decided to do a compression test after driving around. Here are the troubling results (which I have not adjusted for my elevation, which is 6500 feet...but I don't know that doing the elevation adjustment would make that much difference in this case...)
Cylinder 1- 75 first time, then I could only get it to 60
Cylinder 2 - 89 then 86
Cylinder 3 - ZERO (checked and rechecked many times)
Cylinder 4 - 115 then 110
My next step is I'm going to check the compression on my spare engine I picked up. I'm kind of at a loss what to do with the engine in the bus. Should I check for a stuck valve, or am I looking at an engine pull/rebuild?

Oh, also...I was noticed a few weeks ago that I (along with the team I manage) is being let go on May 25th. 16 years and two cross-country moves for the company...it's not been a great few weeks! I was really hoping to drive the bus to the VWs on the Green show next weekend. Bummer.

[RSorak 71Westy]

Have you checked the valve adjustment on 3? This is the 1st thing to check when coming up zero on compression.

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Have you checked the valve adjustment on 3? This is the 1st thing to check when coming up zero on compression.

Not yet. I had planned to do that next. I may get a chance to do that yet this afternoon.

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I adjusted the valves, and #3's intake was 3 1/2 turns off (counterclockwise) before making contact...so 5 turns total when you take into account the 1 1/2 turns clockwise for adjusting, if that makes sense.

I rechecked compression, and here are the new totals:
Cylinder 1 - 94, then 75
Cylinder 2 - 83 then 81
Cylinder 3 - ZERO
Cylinder 4 - 110

[drober23]

First, I'm really sorry about your job. Good luck and godspeed on the job search!

#1 and #2 are marginal, and with #3 showing zero it's time to pull those heads off and have a look. Any idea why the variation in readings on the other cylinders? Was your battery going down, or were you having trouble seating the gauge?

If you have a spare engine, it's time to take a look at it too. What do you know about the spare?

[SlowLane]

3 1/2 turns in before zero lash? I'm going to go out on a limb here and suggest that your #3 intake valve seat has parted company with the head and is wedged in there keeping the valve open. Been there and got the t-shirt.

If you're lucky the valve isn't propped open enough to kiss the piston crown at TDC, though that may change now that you've re-adjusted the lash on that valve. Proceed carefully from here, as you may end up doing more damage.

If you pull the rocker shaft off for #3 cylinder, is the intake sitting much further in than the exhaust? If you shine a light down into the spark plug hole you might be able to see the top of the valve head and maybe also a piece of the valve seat.

Best of luck.

[Amskeptic]

I adjusted the valves, and #3's intake was 3 1/2 turns off (counterclockwise) before making contact...so 5 turns total when you take into account the 1 1/2 turns clockwise for adjusting, if that makes sense.

I rechecked compression, and here are the new totals:
Cylinder 1 - 94, then 75
Cylinder 2 - 83 then 81
Cylinder 3 - ZERO
Cylinder 4 - 110

3 intake has seat recession. Pull the engine time. Dropped compression after a valve adjustment is typical for hydraulic engines, they are holding the valves open through overlap a little.

I hate your stupid company, those bastards.
Colin

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First, I'm really sorry about your job. Good luck and godspeed on the job search!

#1 and #2 are marginal, and with #3 showing zero it's time to pull those heads off and have a look. Any idea why the variation in readings on the other cylinders? Was your battery going down, or were you having trouble seating the gauge?

If you have a spare engine, it's time to take a look at it too. What do you know about the spare?

Thanks...I've had a couple of interviews so far, but nothing yet. Not sure about the spare, other than it's a GD, and mine is a GE. The guy I bought it from said it was his dad's bus motor, and was leaking oil where the #1 cylinder mates to the block. He said it ran great, he just kept adding oil.

I adjusted the valves, and #3's intake was 3 1/2 turns off (counterclockwise) before making contact...so 5 turns total when you take into account the 1 1/2 turns clockwise for adjusting, if that makes sense.

I rechecked compression, and here are the new totals:
Cylinder 1 - 94, then 75
Cylinder 2 - 83 then 81
Cylinder 3 - ZERO
Cylinder 4 - 110

3 intake has seat recession. Pull the engine time. Dropped compression after a valve adjustment is typical for hydraulic engines, they are holding the valves open through overlap a little.

I hate your stupid company, those bastards.
Colin

Me too my friend. I've started the process of engine removal...hope to get it done this weekend. Question for you....what is the best course of action? Should I put the spare engine in as is (meaning just do a straight swap for the engine that's in the bus now) or try to maybe pull the head off the spare and use that? Or can/should that be done?

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Hi everyone - just wanted to let you know I'm still alive. :) I haven't made very much progress at all on the bus, which is pretty sad considering I had the whole summer off! But I did land a fantastic job in September, making almost the same pay as before for a much better company.

Now I'm getting the itch to get working on the bus again...I dreamed last night I finally pulled the engine.

[Amskeptic]

Hi everyone - just wanted to let you know I'm still alive. :) I haven't made very much progress at all on the bus, which is pretty sad considering I had the whole summer off! But I did land a fantastic job in September, making almost the same pay as before for a much better company.

Now I'm getting the itch to get working on the bus again...I dreamed last night I finally pulled the engine.

Good to see you again.
Lessee, at the rate you're going, you will need a day with me to perform a disassembly/diagnosis/parts list in early June, then a day with me in August reassembling everything in twelve hours flat. Then you have all summer to clean and paint.
ColinColdInNY