I couple of years ago I followed this advice (I saved it exactly) for adjusting the AMM on my '84 240.

"...I just replace my '86 245 AMM and set the resistance between terminal 2 and 6 at 300 ohms using the screw. Runs fine and passed emission with flying colors...."

Now, I'd like to check the AMM on my '93 -- is this advice (300 ohms, between terminals 2 and 6) still valid, or are there different instructions for the '93 (obviously, the injection system is different, so I thought the AMM might be, too).

Thanks.

Thanks for pointing that out to me.

I guess the previous owner installed the wrong AMM -- this one definitely has the screw (just like my '84) and the plug is missing, too, exposing the screw. I guess I'll have to look for the correct replacement.

Ken, I bought a 91 once where someone stuck an -007 AMM in. It ran fine, at least for the trip back from the street-corner selling place 40 miles away; don't know about emissions, because I swapped in the right one when I saw that screw, too. The right one for LH2.4 is -016 (last 3 digits of the Bosch p/n), and if you have the LH3.1, I'm not sure-- see if Fitz responds below. One way to tell for sure which system you have is get the bosch number from the ECU behind the right passenger kick panel.

Either way, on a '93, the screw won't affect anything.
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Art Benstein near Baltimore

I'll have to check under the kick panel to see what ECU I have. I hope the p.o. hasn't screwed things up too much.
Thanks for the reply.

No mixture screw if yours has the right AMM. The computer has the ability to adapt, so the adjustment was removed.
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Art Benstein near Baltimore

Art is correct, the '88 240 was the last of the LH Jetronic 2.2 vehicles (North American Market) and all of the later 2.4 and 3.1 vehicles have adaptable/learning ECUs. -they also use the 020 AMM and no adjustment provisions are included.

God bless,
Fitz Fitzgerald.
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'87 Blue 240 Wagon, 248k miles.

I notice you say "-020" AMM. Is that what comes on an LH3.1? The metal film element instead of hot wire? I've never seen an LH3.1, and LH2.4 uses the -016 hot wire AMM. Is there any obvious sign to point out to Ken to distinguish between 2.4 and 3.1? I don't know how different the TPS looks to know whether that is a good clue.
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Art Benstein near Baltimore

Oops. Art, my bad. Thanks for pointing out my error.

Yes, the 016 is the AMM that should be in his vehicle if it's a 2.4.

Observing the differences between the 2.4 and 3.1 systems? -oh boy. I can't remember anything that just "jumps out at you." I'll have to get back to you on that...

Come to think of it, aside from the heated film element and the variable resistor (Potentiometer) in the TPS, what else is different betweeen the 2.4 and 3.1?

God bless,
Fitz.
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'87 Blue 240 Wagon, 248k miles.

Fitz, I had no idea what you said was in error. It is gracious to thank someone for pointing out errors, but I am frankly ignorant of 3.1 systems.

Just for my edification I looked in FCP's catalog to see what was claimed for the LH3.1. Says the AMM is a 0 280 217 001. And lists an ECU with -572.

But I still can't visualize what obvious thing would pop out as an obvious differentiator.
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Art Benstein near Baltimore