posted by
someone claiming to be Volvouser
on
Tue Jun 21 07:21 CST 2005 [ RELATED]
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Today, I helped my neighbor with his -89 B230F with LH 2.4. It was suffering from a "starting, then dying" problem (idled perfectly at 750 rpm, though). At first I cleaned the throttle body. Needless to say, I was very dirty. It led to an improvement but unfortunately, it was far from perfect. Therefore, I decided to make a base idle adjustment.
According to Haynes, base idle is adjusted in "limp home" mode, which could be forced into by pulling the connector to the AMM. I tried that, but it still idled at around 750 rpm.
Therefore, I tried to remove the connector to the IAC which resulted in an extremely low idle, ~300 rpm. After noticing that, I adjusted the base idle screw until it idled at a steady 500 rpm (as suggested). After reconnecting the IAC and adjusting the throttle position switch, it started easier than ever and my neighbor was happy!
Now to my question: Did I set the base idle correctly? If not, could there be any problems?
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" According to Haynes, base idle is adjusted in "limp home" mode, which could be forced into by pulling the connector to the AMM. I tried that, but it still idled at around 750 rpm."
Which Haynes manual (and page#) said to pull AMM connector?
Sounds like you got the idle set pretty close, but I believe it's usually done by grounding a test point to shut the IAC. Maybe you got the same effect by disconnecting the IAC.
I think that using a hose pincher on the IAC air inlet hose will also work.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.
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I was under the impression that there was no base idle adjustment for LH2.4. At least not like for LH2.2, where you ground the test point and turn the black thumbscrew on the throttle body. I thought LH 2.4 had no thumbscrew (and presumably no test point to ground). And as for idle mixture, the LH 2.4 doesn't have an adjustment pot like LH2.2 does either, does it? I was under the impression that in LH 2.4, everything was supposed to be handled automatically by the ECU.
The only thing I've seen is a procedure for adjusting the rest position of the throttle plate (I forget if this is in the Haynes 940, Bentley 240, or both). I always wondered about this though; I thought it was a "fudge" that would be compensating for another problem (like IAC not working correctly, or fuel mixture being off). I assumed that with both LH 2.4 and 2.2, you could mess with the throttle plate, but shouldn't have to.
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David Armstrong - '86 240(350k km?), '93 940T(270k km), '89 240(parts source for others) near Toronto
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David,
You are quite right. (Note to self: Wake up before posting.) I led myself astray when I read how Volvouser unplugged the IAC. Then I went from there straight down the Garden Path.
But there is an IAC "connection" to the throttle position, TPS, and linkage adjustments in the Regina Fuel System green book. There, the Repair Activity for "Checking the throttle housing setting" begins with "Checking the need for adjustment" by pinching the IAC inlet hose shut (engine at warm idle).
It then says, "Engine speed should be below 500 rpm. It is not a fault if the engine stops".
If speed is too fast, the throttle stop screw is adjusted for 480-520 rpm, with follow-up checking for proper TPS click.
So it seems that Volvouser achieved the same effect by unplugging the IAC (which must default to shut) and then adjusting the throttle stop screw for a smooth 500 rpm. Whether or not this affected the TPS setting is an open question.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.
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posted by
someone claiming to be Volvouser
on
Wed Jun 22 07:15 CST 2005 [ RELATED]
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"Whether or not this affected the TPS setting is an open question."
Yes, I had to readjust the TPS after I had adjusted the throttle stop screw.
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Nice job.
Sorry I failed to notice the TPS adjustment in your opening post.
But I'm still curious about that Haynes "limp home" reference. Could you tell me which manual that was in? And page number?
IMO, Haynes manuals aren't what they used to be in the 120/140 days. But I keep some around as sometimes they have a good picture that isn't found in the Bentley 240 manual. I tend to avoid the 740/760 manual, since I have a few green books for the Regina 940.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.
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posted by
someone claiming to be Volvouser
on
Wed Jun 22 09:55 CST 2005 [ RELATED]
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Unfortunately, I have a foreign version of the Haynes manual so the page reference is most likely not the same as the English version. But in my version the first page in chapter 4 part B (4B*1) states that: "idle speed for LH2.4 Jetronic in "limp home" mode: 480-520 rpm. A translation of 4B*9 section "Constant Idle speed system - general information" says: "...in the systems mounted on B230F and B234F, idle speed is under adaptive control...no adjustments are possible except in "limp home" mode (see chapter 1)...".
I knew that limp home mode was activated when the AMM was disconnected, therefore I tried that method at first. You were right, the Haynes manual doesn't say that, I did.
Hope that will make things clearer!
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I think the idle for an auto tranny is 800 and the manual idle is about 650. i dunno. if your idle is too low, you might stall if you don't slowly accelerate from a stop. too high= bad gas mileage. i don't know if i helped much, but good luck.
Joe
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Burn some ricers... '84 760 Ti, '82 244 GL, '84 244 DL, '85 245 GL, '89 240DL, '86 740GLETi
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posted by
someone claiming to be Volvouser
on
Tue Jun 21 22:39 CST 2005 [ RELATED]
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...but didn't find the answers, hence this question! But perhaps I didn't read it thoughroughly enough.
My neighbor is happy and maybe I shouldn't be concerned about this issue!
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Under the "Engine: Fuel Injection" section.
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alex
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Geez... how come none of my neighbors are willing to work on my Volvo? Want to drive to MA?
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Chas Mike, former '85 760 Diesel (loved it!); now '89 740GL 215k and counting
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