Cold idle issue

[WestiCoast]

My 84 Wesite 1.9L will not idle when it is cold. Also there is a loss of power at the very low end. I need to slip the clutch in first gear to avoid stalling. I have a Bentley and the Digijet manual. I live in North San Diego County so it was 45F this morning.

-I have checked and cleaned the Aux Air Valve.
-I have tested the Coolant Temp Sensor in cold and warm conditions.
-I checked the Air flow Meter. I found a high resistance spot at the low end of the Air Flow Meter and swapped it out with another one it better condition.
-I tested the Fuel Pressure at idle.
-Checked for vacume leakes with propane.
-And last night out of desperation I replaced the Oxygen Sensor. Mostly because I could not test it well enough without an analog voltage meter and it was only $20 at the FLAPS.
-Last month, long before this problem, resealed my fuel tank and replaced the fuel filter.
-Also because I am new and I know its coming, all my fuel lines have been replaced.

In messing around with this and testing everything I discovered that if I start the engine cold with the Air Flow Meter unplugged it idles well. So this morning I unplugged the Air Flow Meter and let the van warm up. Otherwise I am sitting in the van holding the throttle trying to keep it steady. Which is a chore because steady throttle does not produce steady RPM when it is cold. When driving the van all is well above 2K RPMs. Can the Vanagon Elmers of The Samba see anything that I might be missing?

[seanjenn]

Although I doubt this will be your issue...I always double check my adjustments to the TPS switches(2) when I have an idle issue of any kind.
Very easy and quick to do, just go ahead and memorize the procedure per Bentley.
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1987 GL Sunroof
2.1 4 spd

[spacecadet]

Major ground straps and any "ground clusters"..

My idle stabilized significantly once I cleaned or replaced corroded grounds. Cleaned the spot where they ground to the body and a little grease.
_________________
Daily Drivers Only
--
1990 Volvo 740 Turbo(Sold)
1986 Mercedes 300 Coupe (Sold)
1954 Volvo PV544 (Sold)
1990 Dodge D250 Cummins (Totaled)
1990 Vanagon GL 2.1 Automatic (Sold)
1968 Ford F250(Current)

[WestiCoast]

Ok I went thru the checks in the Bentley. I am not getting power to the idle switches(should be 5v). But what I am looking at does not look like the picture in the Bentley. I have a white wire coming out of the wiring loom going into one side of the idle switch. Then I have a brown wire with a yellow stripe going from the other side of the idle switch to the one side of the full throttle switch. But there is no wire on the other side of the full throttle switch. I don't even see one hanging around that might have broken off or a bare terminal where it should be connected.

Should my Full throttle switch have two wires connected to it or just the one? Looks like in the Bentley there are two and the second one goes to ground.

[kenwilfy]

Does your van actually idle when it is warmed up?

Usually what I have found to cause this problem is improper valve adjustment. If the valves are adjusted too tight, when the van is cold the high oil pressure will hold the valves open and give you a low manifold pressure, low compression, and poor idling. Do a cold compression test. Then adjust your valves to zero lash (just touching) and do another compression test. Compression numbers should come up and you should have a good idle when the van is cold. Let me know what you find out.
_________________
Thanks,
Ken Wilford
John 3:16
www.vanagain.com
856-327-4936

[Ahwahnee]

[WestiCoast]

Ahwanee that picture is very helpful. Looks like my full throttle switch is not functioning. But after looking a little further my idle switch is working. I checked continuity between the white wire and terminal four at the ecu connector and it was good. Also I checked continuity to the brown and yellow wire with the ground block on the driver’s side of the engine and it was good. I pulled the full throttle switch out and this is what it looked like:

Missing one terminal. These are cheap right? Ill probably try and solder on a terminal when I get home tonight.
kenwilfy It had skiped my mind but I did do a valve adjustment not to long before this started happening. I’ve been messing with this for a week and a half. Tonight I will go check and readjust my valves. I hope that’s it.

[seanjenn]

Sometimes the switches are a pain to find, I think they're about $60-ish.
If you can't find new ones, try the junkyard.
I believe there were some other VW models that used these if you can't find any Vanagons.

Also, when you get it all back together make sure that BOTH of these switches are adjusted properly.
_________________
1987 GL Sunroof
2.1 4 spd

[WestiCoast]

I readjusted my valves last night. It’s a bit quieter now and it feels like a little more power on the highway. But unfortunately my idle is still looping and stalling when cold. Its fine once it warms up. For whatever reason unplugging the air flow meter fixes the idle still. And there is no torque below 2K RPMs. My idle switch is funtioning as it should. I am going to worry about the full throtle switch after I get this figured out.
I think my next task is chassis grounds. I have all my engine grounds soldered and cleaned. I need to find and clean the grounding straps between the engine and the body.
What is the best way to check for resistance between the battery ground cable under the passengers’ seat and the engine? Should I hook up a battery jumper cable to get my mulitmeter close enough to the engine to test? Will the jumper cable alter the reading?

[seanjenn]

As for any of the grounds, if they are still the original braided style, just replace them. Make your own ground staps out of battery cable and 5/16 cable lugs. Waaaay better than the original stuff, might as well check the grounds that are directly above the fuse panel. There are two "crowns"up there with a bunch of wires attached, those are all grounds as well.

I'd get that full throttle switch on there, it might be part of the problem, as bizarre as that may seem. It is a Vanagon.........
On my 84 I had an issue where the van would "engage" and "dis-engage" sharply when you pushed and let off the gas during around town driving. Ran great on the hwy except being weak on the long hills.

Started looking around and found the full throttle switch to be way out of adjustment, not even able to be triggered.
Even though it was the full throttle switch, it had more effect, on in town driving than on the hwy.
Adjusted the switch, about a month ago and before driving the Westy from Denver to Bellingham, WA and so far so good, no issues what so ever.
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1987 GL Sunroof
2.1 4 spd

[floggingmolly]

WestiCoast,

I'm down in UTC and have one I think will work. Here's a photo (a bit dirty).

I think it came off of an 82 when I was at the pick-n-pull but looks the same as yours.

I sent you a PM bu of course can't attach photos there.

Scott
_________________
'85 Wolfsburg Weekender

[WestiCoast]

I had a glimmer of hope for resolution today. I picked up a used cat and muffler and installed it this morning. I started it up cold and it ran like a champ. Idle was a little high but I had plenty of power below 2K RPMs again. And now that my exhaust is free flowing again I went to adjust the idle and timing back to where it should be. But I can't make it idle with anything less than 15 degrees of advance and the idle speed screw has no effect. I hate to even speak the words. But is it possible that my cam timing could be off a tooth? I really don't know what else to look at. Let me recap what I have checked in hopes that I might be missing something.

Vacuum Leaks(checked with propane)
Aux-air Valve
Temp I&II
Resistance sweeps smoothly in AFM
Idle switch
replaced oxygen sensor
checked vacuum and mechanical advance
New spark plugs
Fuel pressure check
Valves adjusted(zero lash)
Checked grounds
swapped ECUs
swapped idle stabilizers
swapped cat and muffler

I'm sure there is something I am missing. I think I have checked just about everything that is bolted to the engine except the transmission.

I still cant set timing to less than 15 degrees timing. I am stumped.

[Ahwahnee]

[WestiCoast]

I don't think so. Also I have swapped out two other AFMs from friends with no change.

[WestiCoast]

I am slightly out of my routine today. I forgot my Bentley at home. I usually spend an hour or so poking around my engine bay looking for what might cause my idle issue. I know on the distributor there are only two ears at the bottom of the shaft so it would be difficult to have the distributor in wrong. But I think there is a second shaft that goes down into crank case. Is it possible that the lower distributor shaft could be off one tooth. My engine runs well with 15 degrees of advance. Any less and it will hardly run at all. Is it possible to remove the lower distributor shaft without disassembleing the whole engine?

[WestiCoast]

I think that my distributor drive gear is off 180*. But I am not sure how exactly I can check.

The Bently shows how the distributor drive gear should be installed on 28.32. Here is the picture and exlpination:

And this is what mine looks like. The picture doesn't show it but the U notch indicating TDC#1 is lined up with the seam in the crank case as it should be.

(note: I tried rotating this image but it didn't take. The crank pulley is to the right and the water pump would be on the bottom.)
I think there is some chance that when the PO had this engine rebuilt, approximately 30K miles ago, the distributor drive gear was installed 180* out.

I have THOROUGHLY checked all the fuel injection components. Also I am getting good spark. But When I set my timing at 5* after TDC it will barely run(and not at all if its cold). My timing is currently set at 12* before TDC and it idles smoothly at 1000 RPMs. But will not idle smoothly any slower.

I have read stories before of these boxer engines being run for thousands of mile 180* out. And after running through everything in the engine bay at least twice, I think this is the only remaining system left unchecked. And I would like to check it out without divorcing the crank case. Is there a way?

[WestiCoast]

I got some help from a new friend today. It tuns out I had two problems. My vacuum retard was not working and my CO adjustment screw also needed some adjustment. My vacuum advance was working just fine but the retard was not working at all. We replaced it and was able to set the timing at 5 degrees. It runs great now idles well now that the timing is correct. My Co adjusting screw was five turns out and after adjusting it using the O2 sensor it was at one and a half turns. I had been weary of even touching the CO adjustment without a gas analyzer. I'm sure that most of my issue was in the vacuum retard. But my problem is solved and I know a whole lot more about my van now. I have been thru all the fuel injection and ignition systems now. I had a feeling the whole time that it was going to be something simple. I checked the vacuum advance a long time ago. And I know that the vacuum retard was getting plenty of vacuum at idle. But I must have neglected to check that the vacuum retard was actually moving the rotor.

Thank you guys to spent time answering my questions. Now I can finally move on from the work I need to do, onto the work I would like to do. My next project is a Honda CRV center console that will not impede my swivel seats. I will post that in a different thread when it is time.