Electrics - Knock Sensors - 1800 RPM max - Death?

[oldmako]

218,000 miles on my 1999 Q. KS replaced by previous owner sometime prior to 2007. The car has behaved flawlessly since the day I bought it with 106,000 miles.

While cruising down a remote the interstate at 3 am at 80mph the car was rocked by a massive shudder and instantly lost power. TCS/Slip and ABS light illuminated. I pulled over and the car died.

I switched the IGN off, let it sit 20 seconds and the car started instantly, but was stumbling at idle. It cleared after a few minutes and I could gently rev the engine. Both idiot lights remained on. I was able to nurse the car home at no more than about 40mph and 1700 RPM. There was very little power available. Any attempt at more throttle was greeted with bucking and a loss of power. It would then recover a bit and I continued on home.

This sounds like a failure in the KS circuit to me, but I'm generally clueless, shiftless and a malcontent. And, I'm no mechanic, just a guesser and parts replacer.
I tried pulling and inspecting the two items in the fuse box which relate to ABS and TCS. Both appear fine, but it was only a visual inspection.

Love to hear anyone's opinion on what's wrong with my car. I am (sadly) leaning toward calling the man from ACME and donating my car to a charity and taking the tax benefit. This is because -

1. 217000 miles
2. Rust. Trunk lid, and at least three of the fenders where they mate with the body cladding. The car was painted, so this rust may be just waiting to explode.
3. Bad AC. $$$$$ to fix if compressor.
4. Leaky valve covers. Pain in the a**. The top of the engine is covered with very old and brittle electrical components, connectors and wiring. Ditto the vacuum stuff.
5. Needs 4 shocks and all mounts, rubber etc. $$$$$$$

Somebody please tell me this is a simple fix that I am missing out on. Because I think it needs a new KS harness and Sensors. In other words, lots of work and pricey.

[elwesso]

KS wouldn't do that type of thing. if KS are bad, the car will idle fine whatnot but will just be really down on power, you won't get what you saw.

Do you have any trouble codes? Sometimes when you get the Christmas tree of lights on the dash, the alternator could be suspect.

I think you'd need to do a little more digging to find out. Nothing stands out because multiple things could cause the issue. What's odd is that it happened so suddenly.

[oldmako]

I haven't check the codes yet. I tried starting it this morning and it will crank and catch, but then just dies. If I can get it to idle, I'll check the Voltage at the batt to see if the ALT is putting out the juice.

I should add, while limping home the car would idle fine at stop lights. It was when the throttle was depressed more than about an half inch that it would crap out.

Seriously, this engine has been a silky smooth sewing machine and was operating perfectly when this occurred. I use it for 200 mile work trips and frequently take her WELL in excess of posted speeds when on empty stretches of interstate in the middle of the night. The engine has been the cars most bulletproof component.

[elwesso]

Honestly it sounds like maybe a fuel pump/fuel filter to me. First thing I'd check is fuel pressure after the fuel filter. You can do this without having the car idle. It's easy to test and will eliminate something rather easy. The old Q's will do similar type things when the fuel pump is weak, although usually they crap out all together.

You should see about 34psi at idle, and 42 psi when you turn the key on. While fuel pump issues aren't as common on 2nd gen Q, at 218k miles I wouldn't rule it out.

What happens if you would give it gas at idle in either park or neutral?

[oldmako]

The day it died, it would behave perfectly normal at the lights, although it was in Drive. But, I was only revving it gently. I did not put a foot into it. I don't own a fuel psi gauge, so I'll pick one up at Advance.

[oldmako]

I checked the codes today, twice.

First I read the following...

P0100 01/08 07/08 Mass Air Flow

P0325 2/08 Knock Sensor Circuit Malfunction

P0304 3/08 Misfire

P0440 04/08 EVAP Diagnostics

P0330 05/08 08/08 Knock Sensor Bank 2

P0160 06/08 02 Sensor No Activity Detected Bank 2


Then, I disconnected the BAT and let it sit for an hour. I restarted the car and it promptly quit. Again. Third try it started and idled smoothly UNTIL I added some gas. Not too responsive, and not too happy, but it ran.

I then read-

P0100 P 01/01 MAF
---------------------------------------------------------------------------------------------------------

Assuming that the first group of codes were "thrown" because I was driving the car for some time since the last time I read the codes, and because they may have been in response to the cars near catastrophic shutdown of last week.......and assuming that the last code...MAF... is now present with none of the others....would it be safe to assume that there is an issue with my MAF, and or its associated wiring?

Hate to toss money without some sense of a reasonable diagnosis.

Any ideas? Anyone got a used MAF for sale?

Too cold and too windy here today, off to work tomorrow. Upon my return I will pull the MAF, clean it and the connectors and try it again. Thanks for any input.

[Q451990]

I'd say that out of that list the MAF code is most likely your culprit... just a guess though.

Heath

[oldmako]

I found an inexpensive, though probably junk MAF online. When I return from my trip I will install it and post up results.

I would hate to shoot this car, but its issues taken in aggregate are getting voluminous and expensiveamous.

[OwnerCS]

Back in the late 70s I that happen to a Cadillac while driving down the interstate. It turned out to be a collapsed muffler baffle. It would allow enough exhaust flow to idle and no more. Though I haven't seen a Q owner experience anything collapsed muffler yet.

[oldmako]

Bad MAF.

Fixed for less than 35 bucks. NICE

[Q451990]