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I am working through a problem with a 240GL. It would start, definately firing and then immediately stop. After having worked through all the usual checks, both pumps worked, the relay was good, all wiring checked out, but the fuel relay was not received ground return from the ECU pin 20. Bypassing the relay would result in a startup but the running was very rough ( this seemed to be the main difference to the information I had observed in some of the other threads I had read in the forum). It caused me to suspect that the ECU was at fault because ignition, sensors and earth connections etc all passed and the AMM gave correct readings. I had been inspired to look at these factors after reading some informative comments from Bruce Young & Art Benstein, thinking that the ECU was getting a false "no spark" indication from the ignition.
Now here comes the rub, if I disconnect the AMM it starts fine and runs very smoothly, relays/pumps ECU all work as they should. I had heard of people limping to their destination by disconnecting a failed AMM and therefore would have expected it to run roughly. It is an LH 2.4 and the resistance between terminals 2 and 3 is right in the middle of spec at 3.2ohms. I can't check the burn off function because with the AMM connected it will not run.
So before purchasing a new AMM to see if that fixes it thought someone may have had this same problem and can help, while I go and clean up all contacts and have a closer look at my AMM.
Wayne aka Aquarius115
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If you need to fix your AMM, http://www.programainc.com/ might help. Someone on the BB recommended them, I know nothing about them. Apparently a 3 year warranty, repairs around $100.00, IIRC.
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Hi Wayne-
unless you're wrong about the year, it will be equipped with LH 2.2, and you'll need a 007 AMM to fix it. If it's actually 89-up, it will be LH 2.4, and you would need a 016 AMM.
Easy to swap, just match up the number before you do, they're not interchangeable.
The car will probably die unpredictably under hard throttle with the AMM unplugged. That was my experience with a troublesome 87. It would idle smoothly for hours; full throttle, even against the brake, sitting still in the driveway, and it would stall after 15 seconds or so.
--
Rob Bareiss, New London CT ::: '87 244DL/M47- 234K, '82 245T/M46-182K, '89 244DL/AW70- 212K Not too distant past: 86 244DL 215K, 87 244DL 239K, 88 744GLE 233K, 88 244GL 147K, 91 244 183K
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Thanks Rob,
The year is correct and you are right it is a LH 2.2
What confused me when trying to identify the FI type was that in the Haynes manual (misleading) the schematic for the LH 2.2 does not match but the 2.4 did, which is why I thought it was a 2.4 - however that's now clear, thanks.
What is it that normally fails on the AMM, a visual inspection shows the platinum wire the intact and very clean, so is it normally the hybrid circuit?
Wayne
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One common reason for AMM failure is that one of the sensor wires is actually broken. These are VERY tine platinum wires, but are visible in very good light by looking through the AMM. As I recall, they should form an almost continuous loop from where one electrical connector comes in, around to the other one. If you can see the wire and it's not continuous (broken like a light bulb fillment) then there is no doubt the AMM is a goner. Of course, it could be bad with an intact wire too.
Ebay is the best source for them, but if you have a local pick-n-pull, that is even better.
I suggest you disconnect the silver preheat hose that goes from the exhaust manifold to the airbox. Failure of the thermostat that is in the airbox allows hot air to get to the AMM all the time (rather than just when the engine is cold). Or if you are concerned about start-up emissions or live in a state that will physically inspect under your hood, you can replace the airbox thermostat instead.
--
Andy in St. Paul, '91 745 Regina 198K mi, '89 244 141K, '87 245 RIP
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Thanks Andy,
Visual inspection of the AMM shows the platinum wire to be intact and very clean, so obviously something in the circuit has failed.
This is a great forum!
Wayne
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In limp home mode, it will run smoothly. The "limping" is lack of power on acceleration. With the AMM disconnected the ECU generates fixed injector pulse width, meaning the amount of fuel is proportional to the rpm instead of the amount of air being measured. So idle is smooth indeed.
The AMM is almost certainly the fault, unless you find a problem with the plug or harness, which with your symptoms, I doubt very much. The resistance measurement is worthless as a test of AMM goodness.
--
Art Benstein near Baltimore
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The wire is good in the AMM so obviously the hybrid circuit has failed.
Thanks for all your help, I am now shopping for a replacement.
Wayne
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Actually it is NOT an LH 2.4 - they never appeared until 89-93.
If you are looking for another AMM, check on E-Bay first. If you are a little patient you can get a really good price on one.
http://pages.motors.ebay.com/browse/parts.html
Just do a search or Volvo 240
Make sure you check the numbers from your old one so they will match.
I think the last three digits should bee 007 - maybe, maybe not. Double check to make sure.
Todd :-)
--
1990 245 Wagon - 187000 miles; 1988 244 Sedan - 123000 miles
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I was confused by the Haynes manual about the version of FI, the schematic for the LH2.2 does not match (should have bought a Bentley).
Wayne
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What part of the Haynes schematic (page 4A-28?) didn't match? I don't use the Haynes for much, but many people do (not knowing about the Bentley manual I guess), so I'd like to be able to note a problem there, if the subject comes up sometime.
Thanks for putting me in the same sentence with Art Benstein too. My head is now bulging with undeserved pride. Wish I had half his talent.
Bruce
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.
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posted by
someone claiming to be Mike
on
Sun Oct 17 03:45 CST 2004 [ RELATED]
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My daughters car was misbehaving similary and I found that the intake air hose from the throttle body to the amm had air leaks in it. I got another and it all worked out.
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