1985 Vanagon won’t idle.

[Jbanderob]

Good Afternoon,

I just picked up a 1985 vanagon that will start and run (with throttle) but will not idle, it just dies. I have learned that it had a 2.1 engine installed, but kept the digijet system from the original 1.9.

So far, I have adjusted the idle switch to make sure it is engaged, as well as checking to make sure that it is showing no resistance when engaged, temporarily sealed the air intake elbow with RTV (new one is on order but none of the cracks seemed to compromise through the entire piece), checked the timing at 3000 rpm and set to 35*, and bypassed the idle stabilizer to see if it made any difference what so ever.

I also played with the idle air screw which didn’t make a difference all the way in or out.

My next point of call was going to be fuel filter (s) as the old owner had replaced the tank, filters and hoses, but I am not certain if he replaced the filter before or after realizing the old tank was shot.

If anyone had any other ideas as to what could be causing this I would be greatly appreciative!

Jacob

[jlrftype7]

You need to smoke test the engine to find any sneaky vacuum leaks. Could be a cracked hose, seal, gasket, you haven't seen yet. Big leak at the o-ring on the base of the Crankcase breather 'Tower', things like that.
Last vacuum leak/crank leak I had that surprised me was on the bottom of the crankcase vent hose going from the Tower to the Intake Boot. It split, which flexed open or closed, causing intermittent dying at idle for me.
_________________
'68 Westy- my first VW and vehicle/Bus- long gone.- sold it to a traveling Swiss couple....
'67 Type 3 Fastback, my 2nd car- gone
'69 Semi-Auto Stick Shift Beetle-gone
2017 MINI Coopers, our current DDs
‘84 Tin Top - Hilga....Auto

[SCM]

You might want to try searching for an online copy of the Digijet Pro-training Manual if you don't already have it.

I have the Digifant version and its quite useful, easy to follow, etc.
_________________
'91 Westfalia GL Automatic (GTA "Turbo" Rebuild w/Peloquin) and 2.3L GoWesty Engine

[Jbanderob]

Thanks guys,

I am leaning towards a vacuum leak, but I need to make a smoke generator since the wife has zero inclination to help with this project right now and keep the van running while I use some brake clean, even though it was her idea!

The Digijet manual has been super helpful in going through everything, the only thing I don’t quite understand just yet is how to test the Hall sensor, the van runs and times correctly when we give it gas, but apparently the hall sensor isn’t getting voltage as far as the digijet wiring harness is concerned… soo maybe an issue there? I am going to run out to the garage and test the voltage at the sensor itself to see what’s going on.

Jacob

[Jbanderob]

Well was able to get it running, blocked off the brake boost vacuum hose and sprayed some brake clean onto the obvious spots for a vacuum leak. Nothing was changing how the engine was running so I assume there is no major vacuum leaks. I am sure there are some small ones that will have to be addressed eventually.

This van had an MV code engine swapped into it at some point. Will an MV engine even run properly on the digijet fuel injection? Something just doesn’t seem to be adding up with the whole setup.

Jacob

[jlrftype7]