Hello All:

It has been the day from hell-- this AM in -15C weather, my wife called from the side of the road-- the '92 945 had overheated!

Turns out the neck snapped off the radiator (the usual top inlet). I need the car on the road, so for $300CDN I picked up a rad locally and installed it.

The current problem, which predated the rad woes, is that the car will stall on deceleration, particularly if I step quickly off the gas. It only happens under load (in gear). Sometimes the check engine light flickers, but it never sets codes (1-1-1 on sockets 2 & 6). Wiggling the harness for the RPM sensor does nothing.

The throttle body is clean with a new gasket, all the vacuum lines have been replaced recently, the idle air valve is clean and seems to be functioning correctly.

Any ideas?


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Herb Goltz, Aurora, Ontario, Canada '92 245 w/124K mi, '92 945T w/200K mi

Hello, How is the condition of the turbo hoses. I have had them so oil soaked that when going from boost to vacuum the hose colapses. I would also check the fuel pressure regulator. I hope this helps. Pauli

Hello Pauli:

Thanks for the ideas-- the two hoses at the intercooler are new, but the elbow at the throttle body isn't-- I took it off and inspected it-- it is somewhat oil-soaked and if I flex it there is a tiny crack at the sharpest point in the bend (about 3 mm long)-- I went easy on it because I will need to order one from the US and it takes time to get things here. That said, it doesn't look big enough to be the problem-- I am pretty sure it doesn't even go all the way through.

The FPR vacuum line has no gas in it and doesn't smell like gas fumes, but I've had these things fail without drips or smelling like gas.

The phenomenon is pretty repeatable-- if I goose it, then back off the throttle completely, I get a drop in idle speed, sometimes with a flickering check engine light, and occasionally an all-out stall. It doesn't set any codes. Not great for stop-and-go rush Toronto traffic...

Thanks!




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Herb Goltz, Aurora, Ontario, Canada '92 245 w/124K mi, '92 945T w/200K mi

TPS intermittant? (not engaging IAC)

Try measuring it's resistance at the ECU. Make sure it consistently reads the same resistance as you repeatedly force the throttle of its endstop and back numerous times.

If this seems fine, you might want to try the test I suggested in
this post.




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David Armstrong - '86 240(350k km?), '93 940T(270k km), '89 240(parts source for others) near Toronto

Hello David:

Thanks for the response-- I get consistent clicks on cracking the throttle, but I realize that doesn't mean much. Which terminals to you measure the resistance on at the ECU? I would have guessed that it would set a code for a bad throttle position switch, but then again, with OBD-I, all bets are off-- on mine the LED glows dimly as soon as I plug it into socket 6...

I had a look at your post-- when I pull the IAC hose off at the big hose, my car stalls-- is that that telling me something about my IAC? It is a huge leak of unmetered air, so I am puzzled why you would be able to hear the IAC working. I realize now that I could swap the IAC out of my 240-- same year, both LH 2.4.

Thank you as well for your past post on the power steering lines-- I had them replaced at Suter's (too cold on the floor in my garage and the fittings looked rusty as hell, so I decided to pay to have it done). No more steering leaks.

At least the car didn't lose the head gasket when the coolant left in a hurry this AM. I should have ordered a whole new cooling system from FCPgroton.com when I picked the car up in the fall-- I could have bought everything for the price of the rad here.

Cheers!



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Herb Goltz, Aurora, Ontario, Canada '92 245 w/124K mi, '92 945T w/200K mi

In hindsight, my IAC suggestion is apparantly significantly flawed. I'll keep thinking about a test of this sort, but meanwhile, I recall that I've already seen a simple test here that will work. I'm not a big fan of pinching hoses, but that's probably the simplest approach:

- with the car idling, pinch off the inlet hose to the IAC. The idle should drop noticably, and the engine might stall.

- now push the throttle slightly off the endstop, and then pinch off the inlet hose to the IAC. Now the idle should not drop significantly.

Re: the TPS. I just looked at my Mitchell CD, and found 2 things I didn't realize:

1) the TPS ground doesn't go back to the ECU; it must ground near the switch
2) the TPS signal also drives the EZK ignition ECU. I guess it affects advance at idle? Woudln't think this is the likely culprit, but something to keep in mind.

Anyway, the TPS signal is on the orange wire at the ECU - pin 2.
1) disconnect the ECU connector and measure resistance between this pin and ground while repeatedly exercising the TPS switch. The low resistance should be consistent
2) disconnect the TPS and ensure that its harness pin 2 sees ground.

You may instead want to do the simpler test
1) disconnect the harness to the TPS, and measure resistance between its 2 pins while repeatedly exercising the switch. The low resistance should be consistent
2) ensure that its harness pin 2 sees ground

The only downside of the simpler test is that it doesn't ensure the TPS signal is getting to the ECU. That's less likely to be the problem though; if there is an issue, the odds are the simpler test will find it without having to dig into the ECU.



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David Armstrong - '86 240(350k km?), '93 940T(270k km), '89 240(parts source for others) near Toronto