Scott H

I was on the fence about replacing my fuel damper, but now that puppy is on the next parts order. It's the last bit of old fuel related stuff to get replaced; no need to tempt Murphy, right?

minho78

Chris the lawnmower must run pretty good on premium gas. No knocking at all.

SteveNick

Tom, Ihaz944t

Bit of a lull in the KLR saga. Had to do some maintenance at the cottage on Saturday.

This morning I checked out the KLR tube by blowing air through it. It's not blocked but has definitely had gas in it. Re-assembled the KLR at the manifold and the KLR unit and started the car.

I pulled the FPR vacuum line to the air intake manifold and there is no sign of any gas coming from the FPR. Does that rule out the FPR and the Damper?

I thought I could hear some air escaping from the area where the KLR banjo bolt mates with the air intake manifold. Used a stethoscope to confirm and and there is some air escaping. I managed to lose the washer that mounts between the KLR banjo bolt and the Air Intake so I used a standard washer of the same gauge but it's not making an airtight seal. Does this make much difference?

VDO boost gauge is still stuck at 1.

Appreciate any added thoughts.

Cheers:

Steve

dirtyTurbo

Hmm I guess that would mean its not the FPR, or maybe it leaks intermittently? did you try the same with the damper? I dont even know what that thing does but there has to be something putting gas in your vacuum system.

If you clearned out the line and its still stuck at 1 it kind of sounds like gasoline damaged your KLR :/

My guess may not mean much but thats what went through my head, good luck!

Tom M'Guinn

Try pulling the line off the damper to see if there's gas in that line. It almost certainly came from the regulator or the damper. Small leaks may take time to accumulate gas. Not to be negative, but the gas may have screwed up the little pressure sensor in the KLR, resulting in your 1 BAR reading all the time. On the other hand, I'd first try getting the KLR line to seal better on the intake -- if the seal is really bad, then the KLR line might be seeing atmospheric pressure (which shows as a 1 on the gauge). You could check that by putting hand vacuum pump on the klr line with the ignition on to see if the gauge goes down from 1 Bar.

SteveNick

At this point I'm going to get the proper washer and hopefully seal the air leak, although I'm not convinced that will solve the problem.

Even if it does the bigger issue is where did the gas come from? I have to think the FPR or the damper could be the only sources. when I originally leaped to the wrong conclusion about having water in the KLR tube I was led there by the fact that the line had what looked like condensation, in that there were droplets, not a standing column. So it probably accumulates over time.

I need to resolve where the gas is coming from. I can't believe that gas coming onto contact with an electrically charged (non conformally coated) circuit card in the KLR unit is not a potential hazard.

It's looking like I should pick up a spare KLR unit from E-bay but I won't use it until I get the gas source nailed down.

Appreciate the continued interest.

SteveNick

Well, I sealed the air leak and pulled the vacuum line from the Damper to the manifold and no signs of any gas there.

Pulled out the KLR and got a surprise I wasn't counting on. I posted another thread on that topic. Judging from the scratch marks on the KLR someone has been in there prior to my buying the car 9 years ago. Trying to figure out what kind of chips were installed.

Anyway, I noticed a bit of corrosion in the inlet fitting on the KLR where the tube mates to the box. Other than that the boards look to be pristine and there is no obvious gas smell. The pressure sensor component (Bosch) appears to have no corrosion but whether it still works is debatable.

I'm about out of options beyond buying a used KLR off e-Pay.

Thanks for your help to date.

Van

Remind us again what's happening? The car's not producing any boost? The gauge isn't working? Boost goes up then tapers down?

SteveNick

Tom:

The factory boost gauge is stuck on 1 when the ignition is on. Ignition off the gauge returns to .4 as per normal. The last time I had the car out it performed as always but the gauge is stuck at 1.

Van

Ignition on, engine not running, the gauge is supposed to be at 1 bar. That's atmospheric pressure. Once you start the engine, it will move to the left - that's vacuum, or less than atmospheric pressure because the pistons moving up and down are sucking air, creating less pressure in the intake. When you're accelerating, and on boost, the turbo charger it pumping extra air into the intake - this will make the needle move the the right of "1" - this extra air will cause positive pressure, or pressure greater than atmospheric, to be in the intake.

I'm unclear - are you having a gauge problem or a power (boost pressure) problem?

SteveNick

Van:

Ignition off needle is at extreme left. Ignition on needle moves to 1 and doesn't move regardless of throttle position. On acceleration it doesn't move and when I let off the throttle instead of moving to the left it stays stuck at 1.

Van

Gotcha. Then I think it's your dash or the gauge. If the car performs properly while driving (the right amount of boost and power), then the KLR is seeing the pressure in the intake manifold and is adjusting fuel and timing for the boost pressure. Your breakdown is post KLR (although it could be the signal coming out of the KLR...), but I'm going to place my bet on the gauge.

Tom M'Guinn

I'd be careful until you find the source of that gasoline. If it leaked once, it'll leak again. And no one needs gas leaking on their headers!

I would assume the pressure sensor was damaged by the gas, but you can check the voltage on pin 5 of the klr to see if it's stuck at one voltage (a 1 on the guage represents .5vdc on that pin, if the gauge is connected and everything is working).

Tom M'Guinn

Good points -- you would think the engine management would show some signs of a bad sensor. But given the gas-soaking, I'd still be inclined to check the voltage on KLR pin 5. Or, you can disconnect that wire from the KLR, and feed that wire 1vdc to see if the gauge registers 2 as it should with 1vdc.

SteveNick

I managed to pick up a used KLR for an 89 951.

I'm out of my depth at this point so I'm going to take her into my long standing mechanic (he used to work for the local Porsche dealership back when these cars were new).

I won't be installing the new KLR unit until he's got the source of the gas contamination sorted out. I figure with the corrosion on the brass inlet fitting for the KLR tube it's a pretty good bet that the pressure sensor has some crap in it as well.

Is the Bosch Pressure Sensor component still available or is there an alternate part available? If so I could have a backup KLR available to me.

Thanks a lot for your help with this.