Help 86 Jetta GLi CIS-E Problem: Grassroots Motorsports forum: Grassroots Motorsports Magazine

Subscribe get a full year for only $23.95 Sample Free Test Drive—no strings attached

July 16, 2009 10:11 p.m. VWguyBruce HalfDork

Car is a 8V CIS-E injected 86 Jetta GLi. PS and AC removed. AC relays bypassed and removed properly.

Problem occurs at WOT. It feels like the motor loses all power, bogs. At 85% throttle engine revs and pulls smooth. Can't be fuel since it's CIS-E and the loss of power is instant and immediate. So, it appears to be an instant loss of spark. Nothing I've done so far has made a difference. My buddy the CIS guru has no idea.

What I've done:

Different knock sensor, also removed it and wrapped it in a towel.

Replace idle/WOT switches(actually spliced in good tested sensors from A3). Voltage at connector is as it should be.

Tested coolant sensors

Reinstalled O2 sensor, was running it without

Timing is dead on the money although it bobs around a bit

Good plugs/wires/cap/rotor(should be)

Any ideas? Thanks, Bruce
July 17, 2009 12:02 a.m. friedgreencorrado HalfDork

In reply to VWguyBruce:

Can't be fuel? Filter/pump/tank debris, etc.?

Air flow? Maybe the control plate arm isn't tickling the metering valve correctly.

Only things I can think of. Sometimes I consider m'self lucky mine's Digifart.

That being said, I've actually run the Digi box "off the map" at high rpm/high vehicle load (man, wife, toddler, and hatch full of luggage & Xmess gifts from all three of us) a couple of times running uphill on mountain grades. The thing stuttered like I'd hit the rev limiter, even though I was only turning about 5K revs. Maybe the programming inside the CIS-E box is a little more primitive?

I'm no expert, just throwing some stuff out there.
July 17, 2009 9:02 a.m. Travis_K HalfDork

Someone i know had an ABA that did something like that, and it was caused by the timing gear on the crank no longer being firmly attached. It seems that mk2 vws have more than their share of fuel injection issues than other cars of the same vintage (I was actually planning to buy one, but i looked at 4 of them and they all ran terrible, and other people i know who have had them never got them to run right without an engine swap).
July 17, 2009 10:56 p.m. VWguyBruce HalfDork

Thanks guys.

Vortexer mentioned my DPR being off, any thoughts?
July 23, 2009 7:56 a.m. VWguyBruce HalfDork

Swapped the correct O2 sensor back in and not yet addressed DPR amperage mentioned earlier.

Then, just for fun, I decided to get a new cap and rotor since I really didn't know the condition of either. Naturally, the cap didn't fit since we were running a later distributor on the car so for even more fun, I fixed the dangling hall sender on the distributor that came from the factory to make the cap fit. Back to basics is what I'm thinking.

Here's the rub. I can't get the rotor to face the notch at TDC no matter what. To get the motor to start now, I have to point the notch at the wrong side of the motor, the hall sender is bumped up against the block. When the rotor should be facing #1, it's lined up with #2. The later distributor is doing the same thing now and probably was before but ran ok.

All marks/notches lined up at TDC. Do I need to pull the distributor drive gear and get it clocked correctly? Why would someone do THAT to me?
July 24, 2009 12:53 a.m. friedgreencorrado HalfDork

In reply to VWguyBruce:

I've never heard of the dist gear being "off", but if the rotor ain't striking the right pip, it seems the ignition's out of time. Sounds like something worth investigating. Personally, I'd put the motor at TDC, do whatever I had to do to the dizzy to get the rotor pointing at #1, and mark the housing for the "new" location.

Provided it ran good after all my ghetto mods to the distributor, of course. If not, I really don't know where I'd go next.
Aug. 3, 2009 10:35 a.m. VWguyBruce HalfDork

Well Gents, it appears that I've got a combination of things going on. When I "fixed" the throttle switches I used switches off a MK3 and spliced them onto my 3 pin switch harness. I thought a switch was a switch but apparently not in this case. Idle switch seems to be a good swap but the WOT switch is where the bog is coming from.

What the switch was doing was at WOT the DPR current is supposed to quickly drop to -45mA and quickly return to it's normal 9mA. The switch was keeping the DPR current negative for too long causing the bog.

As for the distributor, well, that was my dumb fault. All I needed to do to reclock the distributor was reach in with some pliers and turn the shaft that drives the oil pump. Then I just put the rotor/dist body where it needed to be. Unbelievable after working on cars this long that the solution eluded me for as long as it did. Huge stupid on my part. Too easy.

If anyone might know.... Question on DPR current adjustment. The current was weird at first, it was actually climbing at first from 9mA to close to 15mA while revving the motor, opposite of what it's supposed to do. I was under the impression that you needed to adjust the DPR itself on the back, under the cover screw. Is that right? I had a buddy say he adjusted his on the fuel distributor. Is he thinking of something else? I adjusted the screw on the back of the DPR slightly, 3 different times, and it never made an appreciable difference. It does now decrease to 8mA(correct, increases fuel) as the motor revs and stays around 9.5mA at idle. So I think I'm going in the right direction.

As a result, I was able to autocross it this weekend with the WOT disconnected and ziptied out of the way. Last run was great and would've posted a great time but got two cones. I use my buddy who drives a Scirocco as my threshold of good VW times during autox. Bested his time by a full second. So, once I get the right spring rates in the rear the car should be close to being where I want it.
Aug. 3, 2009 6:26 p.m. friedgreencorrado HalfDork

In reply to VWguyBruce:

Two thumbs up! Stupid cones. I swear sometimes they just jump up out of nowhere. I guess that means I need to do more course walks...
Aug. 4, 2009 7:29 a.m. Paul_VR6 Reader

The adjustment you want is the 3mm screw in the fuel distro, just like a reg CIS car.

What Mk3 'switch' did you use? No Mk3 I can think of uses throttle switches, only throttle position sensors which are fully variable resistance.
Aug. 4, 2009 12:13 p.m. VWguyBruce HalfDork

I stand corrected Paul. I pulled the switches out of my box marked MK3 parts The switches were actually off a later MK2 with a 2 pin connector as opposed to my early 3 pin.

Vortex is telling me to use 3mm screw on fuel distributor for adjusting the airplate rest position and adjust DPR current for power.

I should just get my MS finished huh?
Aug. 4, 2009 12:52 p.m. Paul_VR6 Reader

I will only answer one question. YES. You know which one.