Number 3 is down ........ SOLVED

[RGS Paul]

Ok, I have hit the wall on diagnosis and want an outside opinion.

The patient: 1987 Syncro, mostly stock with about 70k miles on a Tencent life rebuilt 2200 cc wasserboxer. Minor modifications include CB performance 1.25:1 rockers and Manton pushrods. The Fuel injection system is essentially stock and had been running fine, we had just diagnosed a long standing hiccup to a bad oxygen sensor. Total milage just rolled over 245k miles.

The symptoms: the number 3 cylinder appears to not be doing anything. There is a bit on a tapping noise coming from the center of the engine. I have fuel and spark, 110-130 psi cold compression (seriously, it was snowing when I checked) on all four cylinders.

The situation: Just before New Years we went to visit my folks in southern Colorado. On our way home we skied Wolf Creek (climbed the pass great in the snow, she seemed a little down on power but it's over 10000 feet at the summit) then dropped to spend the night in Alamosa. The next morning was quite cold, around -10 °F, when I started the van to start digging her out. I seem to remember that the van was difficult to get to idle and there may have been a noise when I first started it, I attributed it to things just being reluctant to start in the cold. Leaving Alamosa the van wouldn't go over between 55 to 60mph, we tried to diagnose things but nothing seemed immediately wrong, the exhaust sounded funny though. Rather than get a couple of hundred mile tow we aborted further skiing plans and drove back to Los Alamos slowly, the last hills to town were excruciatingly slow.

The next day I started to try and diagnose things. The spark plugs looked fine, #3 was a little wet but I assumed that was because I had moved the van cold. Compression was between 110 and 130 psi on all the cylinders, this was with the engine completely cold. I got things to start and idle again and checked the exhaust temps, that's when I figured out #3 was not firing. Pulled the valve cover, the valves both moving smoothly with engine rotation and the push rods are tight. Checked the spark and there is spark at the plug when grounded to the case. I assumed it was a dead fuel injector and ordered new ones. Installed the new fuel injectors yesterday and no change. The other three cylinders seem to be running fine and the van stated immediately when I went to test things today. Switching the fuel injector connector from #4 to #3 has no effect. The new fuel injectors are spraying great.

I'm stuck. My only thought is that maybe one of the lifters on #3 is dead. I would think that would affect the cold compression value and would be making an unholy racket.

Does anyone have any other thoughts before I start pulling the valve gear off and pulling the push rods out?

Thanks in advance!

Paul
_________________
'87 Syncro 7-Pass. Adventure Touring Vehicle
"Simplicate, then add lightness." Colin Chapman

[tjet]

I'm thinking one if the lifters failed.

I just replaced the lifters on my wbx. I was installing Marcos 1.25 kit, and one of my pushrods had dropped down & knocked off the lifter snap ring while I was installing the shaft

If the snap ring comes off, you will see it hanging on the pushrod. That's easy enough to check with the valve covers off (if your lifters are the snap ring type). You can also try moving the rocker arm to see if the lifter failed.

I ended up replacing all 8. One thing worth mentioning is that several lifters easily came apart as I was removing them. All had a snap ring. My new OEM lifters have the wire clip. Not sure which is better, but I dont see these OEM wire clip ones coming apart as easily.

If you find a bad lifter, you will need to cut out the OEM style tubes. I used these. Make sure you install the 2 small black o-ring seals, and the large metal washer goes on the larger diameter end toward the case. It supports the big white end seal. The head side does not use or need the metal washer as the step on the tube is much deeper supporting the white seal.

https://www.vanagain.com/shop/collapsible-push-rod-tube-for-all-waterboxer-vanagon-83-91

[DanHoug]

check the power balance by pulling the spark plug wires one at a time on each cylinder and note the drop in RPM. if you find one that doesn't change the idle cadence as much as the others, that is a weak cylinder. does it still point to #3?
_________________
-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[RGS Paul]

Ok, I tried to pull the push rods on the left side and found out that they hit the water pipe running from the water pump to the thermostat. That rather put the kibosh on further systematic investigation today since I don't want to (and am not prepared to) dump the coolant this afternoon. It's definitely the #3 cylinder that is lame, it seems to be firing but is not doing its share.

I'm still stymied why a bad lifter wouldn't affect the valve lift. Both the intake and exhaust on #3 are moving the same amount as #4 and the compression on#3 is good. Is it something about the dynamic adjustment of the lifter compared to the static characteristics?

I went for a quick drive to the car wash to clean the underside of the van and there is a strong vibration under certain load and RPM conditions that is engine related (no vibration at the same speed in neutral and idle).

Two new lifers and push rod tubes are on their way from Van Cafe. In a couple of weeks I'll get back in to the deep diagnosis. Any further thoughts are appreciated, I'll report back when I learn more.

Paul
_________________
'87 Syncro 7-Pass. Adventure Touring Vehicle
"Simplicate, then add lightness." Colin Chapman

[djkeev]

No answer to lifes annoying questions .....

But

If you are pulling the water pipe to replace two lifters..... I'd buy two more and do that entire side while it is torn apart.

If one lifter crapped out of a given design, the seven others will be following down the same path sooner rather than later.

Honestly, if one lifter gave up...... I'd be ordering 8


Dave
_________________
Stop Dead Photo Links how to post photos

Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[MarkWard]

A couple tips. When confronted with a cylinder miss that can be pinpointed to a particular cylinder, here are 4 easy tests. Swap the plug wires at the distributor and the plug. If no improvent, swap the spark plugs. No improvement, Swap the injector connectors and last, swap the injectors themselves. Assuming the engine has enough compression to ignite the fuel charge, one of the above tests should move the misfire. If the miss does move when you are testing, it will give you an idea of the cause.

This is often quicker and less expensive than just trying new parts.
_________________
☮️

[hdenter]

∆∆∆∆...Ding...Ding...Ding...∆∆∆. We have a winner! That's the way to do it!

Hans
_________________
'79 triple white convertible bug
'84 sunroof vanagon
'85 weekender

[tjet]

[RGS Paul]

Mark, you're in my prayers tonight brother. I owe you huge.

The new injectors I was willing to eat because I wanted new ones anyway, and plugs are cheap, but I hadn't really diagnosed the wires as thoroughly as I should have. The set was new in the last 6 months so I figured the suspect one was good. I tested the resistance of the wire, and hooked up a spare plug to see the blue spark, and I checked the #3 triggering on the distributer then I kind of ignored it. After seeing your post I tried swapping the #3 and #4 plug wires and #4 dropped out. Went to the shed to get the old Bosch wire and put it back in (I tend to keep old parts if they are replaced for age not failure) and all four are back in the game. Quick spin around the block and everything seems perfect.

You just saved me a huge amount of wasted effort. I thought I had done the easy tests but swapping wires between cylinders hadn't crossed my mind. I tested the component but not the system. I was also trying to track something that would have failed due to the extreme cold rather thank being completely objective, this could have happened any time it just happened to occur then.

I'll swap in the rest of the old wires next week and start shopping around for a higher quality new set.

Thanks again, if you are ever in CO/NM a there is dinner with your name on it.

Paul
_________________
'87 Syncro 7-Pass. Adventure Touring Vehicle
"Simplicate, then add lightness." Colin Chapman

[MarkWard]

A result. Glad it was something external.
_________________
☮️

[tjet]

Cool, glad you got it sorted out.

BTW, here's the correct wires & cap you want.

https://www.vancafe.com/200998031D-p/200998031d.htm

https://www.vancafe.com/03212-p/03212.htm

Note, you will need to have the matching "pin" type coil for the above wire set, which is this...

https://www.vancafe.com/00061-p/00061.htm

...and plugs. NGK BP6ET

https://www.thesamba.com/vw/forum/viewtopic.php?t=497486&highlight=bp6et

[RGS Paul]

That's exactly the setup I was running. I'm not overly impressed with the STI wires, they are loose on the plugs for one. Ordered new Bosch ones from GoWesty last night and informed Van Cafe of the failure.

Paul
_________________
'87 Syncro 7-Pass. Adventure Touring Vehicle
"Simplicate, then add lightness." Colin Chapman

[dabaron]

glad you were able to sort it out with the help of the group. further proof of how this niche VW group is a great community.
_________________
1991 Vanagon GL Camper
i had no idea i wanted to be a mechanic
"burnin oil and cookin coils" -- Destructo

BiWerks Design, LLC

[AtlasShrugged]

I had the exact same problem back in 2012. Got a "dead cylinder" while motoring around. Brand new Bremi wire set from VC. Found thee problem pretty quickly using an old original VW spark plug wire.

VC was great and sent me a then hard to find Bosch wire set and I returned the Bremi(s).

Running just fine for six years.

Dont throw away your good old wire set, cap or rotor if changed for maintenance. You never know.

[tencentlife]

I'm rarely a brand loyalist, except here: Bosch Ultra Premium wireset, genuine Bosch cap and rotor, accept no substitutes.
_________________
Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/

Please don't PM here, I will not reply.

Experience is kryptonite to doctrine.

[dabaron]

[AtlasShrugged]

[dabaron]

[cmayna]

Good thread to learn from. All we need now is a new thread on "building vanagon parts storage sheds".
_________________
'90 Westy / automatic.
If I'm not working on the camper or my '50 Chebbie truck, I'm either fishing with the wife or smoking Salmon.


Craig

[dabaron]