79 FI bad cold idle, high idle coming off highway

[aircooledrides]

hey guys, newbie alert here,

79 westy, fuel injection. i have had this bus for a couple weeks now and it ran well on the drive home and on a 600 mile round trip with the exception of the hi-idle sticking when coming off hi-way speeds and clutching. i resolve that by slowing down-putting the tranny in a high gear-ease out on clutch-presto-idle slows down-def'ly not throttle cable or return spring problem.

on start-up, i have a very rough idle but she runs great at 65mph, also i notice a fuel smell to the exhaust when she's rough idling.

also, po removed the charcoal canister so those hoses are just sitting open to outside air. and egr tube is to open air under bus. i have noticed a sucking whoosh sometimes when i remove the gas cap(it's a locking one-not stock).

ideas? first vw i've had with the f.i.

thanks,
hampton

[dtrumbo]

i resolve that by slowing down-putting the tranny in a high gear-ease out on clutch-presto-idle slows down-def'ly not throttle cable or return spring problem.

I used to have to do the same thing on my F.I. Beetle. I fiddle-futzed with EVERYTHING until I realized someone had put the wrong distributor on the vehicle. I bought the correct one, had it rebuilt by these guys http://www.philbingroup.com/rebuilt/distributors.htm and my problem was finally solved. Now I can't guarantee that's your problem, but take a look at the numbers on your distributor and compare it to the chart here http://www.oldvolkshome.com/ovhignbo.htm .

As far as everything else, you definitely need to block off that open EGR filter tube. A chunk of metal with two holes drilled into it with the correct gasket works just fine.

As far as the whooshing sound when you remove the fuel cap... I've heard of that before, but don't recall the symptoms it creates or what the solution was. Someone else will need to chime in.

Good luck!

[vwlover77]

First thing to do is check all air / vacuum hoses and connections for cracks or leaks. Pay special attention to the "S-boot" between the throttle and the AFM and the hoses and elbow in the auxilary air regulator circuit (buried and hard to see).

The high-idle problem could be a sticky distributor that does not allow the advance weights to pull back in when returning to idle. It would be worth disassembling, cleaning, and lubing the distributor to make sure everything is OK.

As dtrumbo suggests, you really need to block that EGR pipe to get rid of additional air coming in that will lean out the mixture at speed.

Finally, you may want to go through the entire fuel tank vapor recovery system and get it back to stock. It may be that the previous owner had gas-smell issues due to a rotten hose and blocked off parts of the system. That might be causing the vacuum in the tank when you remove the cap.
Check out the info at ratwell.com.
http://www.ratwell.com/technical/FuelHoses.html#fitank

Do you know what camshaft is in your engine? Stock? A stinky rough idle when cold is exactly what my engine had with the CB Performance "Torque Master" cam that was in it for a while.

[aircooledrides]

thanks for the info.

with the egr, can i just unhook the arm attached to throttle or is it recovering air/gas at all times?

on first crank i have to tap the gas a few times to get her going then rough idle til warm.

-distributor is correct, point gap good.
-engine stock
-gonna check the s-boot in a bit, though ihave replaced the smaller line coming off the y already, was hanging loose where it connects to the engine.
-replaced the rubber hose on drivers side in fuel vap system b/c i got gas dripping when filling up

on with the old clothes and back to the bus i go.

[aircooledrides]

just read about TrollFDBelow's intermittent miss at idle. i have fixed 2 vacuum leaks since getting the bus. may play with the afm as it was runnng good when i bought it with the leaks.

so far i sure miss those carbs.

[Randy in Maine]

Seal off both side of the EGR first if you do not need it for emission purposes. Also just remove that arm.

Keep working on getting rid of any vacuum leaks.

Get yourself a vapor canister and hook it up.

Then have a good look a the aux air regulator including the vacuum hoses that go to it.

[Amskeptic]

just read about TrollFDBelow's intermittent miss at idle. i have fixed 2 vac leaks since getting the bus. may play with the afm as it was runnng good when i bought it with the leaks.

so far i sure miss those carbs.

The fast idle from highway speed can be fixed with as little as a 180* turn of the screwdriver on the idle speed screw, that big brass slotted thing staring at you near where the throttle cable is (that's easy right? better than carbs even). If your normal warm idle gets too close to 1050 rpm, the centrifugal weights just get too excited and advance the timing at idle.

So, by turning the brass screw near the throttle cable CLOCKWISE, you can drop the idle down to 900-950, and see if that fixes your idle problem before you go tearing into the distributor.

Do not play with the AFM unless you know what you are doing. The consequences can be subtle and dire if you accidentally lean it out in the highway rpm range, you may not even notice that the power is down (it is "down" on a good day in a bus) and the exhaust valves are getting blow torched.
Colin