Hi,

My 240 sedan runs flawlessly on a cold start, but after a warm start, it runs very roughly for a few minutes until immediately smoothing out. There is absolutely no sign of the problem during operation after a cold start no matter what the outside or engine temperature is, and the problem dissappears completely after it runs roughly for a while after a warm start. It is like a switch, either on or off, no transition. Also, it does this on every warm start, and never on a cold start, and never recurrs during opereration after it has once dissappeared. Is this the ECT sensor? Here's the funny part: I have new brakes that squeak after operating for a short period, so after it stops sounding like a diesel truck, it begins to squeak like a freight car. So for now, I am only driving after giving the car a cool-down period, and staying out of stop and go city traffic to keep other motorists and myself sane. Thanks a million! --Stuart Baker

When you test the AMM, what do you come up with?

Hello,

I found what seems to be the source of my problem: a leaky vacuum line to the fuel pressure regulator. Now with that all patched up, I still can't get it to start. Could losing the vacuum have affected/damaged other components? I am at a loss to think of what I might need to do to reset everything to normal conditions after a failure like that.

Also, to put the AMM possibility to rest, I did the two tests I know of. I got ~3 ohms resistance on terminals 2 and 4 (normal for an LH 2.4 I think), and I also tried starting up with it disconnected, which didn't affect it.

Thank you!

Stuart

Try this test: simple AMM test that rules out all problems but a bad AMM

Thanks, I can do the first step in the test, and I'll do that later, but since the rest needs a running engine, will this be enough to rule either way on the no start issue? Also, would an AMM be damaged by losing vacuum to the FPR, as I think that this was definately my original problem? I've looked through many many old postings on the board, which is helping a lot, but I just can't figure out this problem. Oh yeah, and there's a few more clues: I am not smelling fuel in the exhaust when I crank it, and also, the plugs are blackened and not wet with fuel. I did switch them for a clean set. Okay, I'll report anything new later. Thanks again! --Stuart

Okay, the other shoe has dropped, so here's my update. I just started the car cold, and it ran rough for the first time when it was cold. After a minute it stalled, also a first, and will not re-start. Starter cranks fine, but doesn't catch. I did the diagnostic and came up with the code for no signal for the AMM and the code for compensating for a lean/rich mixture at idle. I erased those codes and cranked it again and got only the code for lean/rich mixture at idle. BTW, this is a 'new' 209k 240 to me, so I'm still developing that 6th sense for intuiting what is malfunctioning, has already malfunctioned and has been fixed, and what to expect to malfunction, and I didn't realize that my 'check engine' light does not work (nor should it for the one code)... Gosh, if only there were a check check-engine-light light or something.... I was thinking of passing the problem to a mechanic, but now I really want to do it myself because it's in my garage until it's either fixed or towed. So are the symptoms a positive match for a blown AMM or AMM wiring? Thanks in advance. --Stuart Baker