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Discussion Starter #1 (Edited)
I have a 1991 350SDL that idles well. It drives really smooth also. My problem is that when you give it some acceleration and quickly come off the gas, the idle dips so low it seems like it wants to cut out. It especially does it if you are at idle and then just stab the accelerator pedal on and off really fast.

Any ideas what could cause this? Or what I should check? Thanks!
 

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Discussion Starter #2
No takers on this one? I know there are are some pretty strong diesel guys on this list....
 

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Discussion Starter #4 (Edited)
Thanks. I'll check it and let you know. Oh, one thing that may make a big difference is that I am talking about at idle WHEN IN PARK OR NEUTRAL. have not tried it when in gear. probably does the same, however.
 

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Don’t use WD40 – use a proper automotive grease or ATF.

It could be an IP timing issue. Check also the ALDA setting, condition of the banjo bolt, and for any loose/broken vacuum lines. What is the transmission doing when the problem occurs? What kind of smoke if any is coming from the exhaust?
 

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Discussion Starter #6
Don’t use WD40 – use a proper automotive grease or ATF.

It could be an IP timing issue. Check also the ALDA setting, condition of the banjo bolt, and for any loose/broken vacuum lines. What is the transmission doing when the problem occurs? What kind of smoke if any is coming from the exhaust?

ok -- go slow :)

how do you time the IP? Is that setting it to the 15 ATDC with the pump locked?

What is the ALDA setting, and how do I do that? What banjo bolt?

Will a visual inspection of the vacuum lines tell me anything or do I need to have a vacuum tool of some sort?

The transmission is in park and I will have to check the exhaust.

All good stuff and if i knew how to do some of this stuff I would be ok!

Could it also be the injectors or the pressure valves on the IP?

Is there anything else on the IP other than the timing that could do it?

I've got a feeling that if I can get this fixed, I'm going to have learned a whole lot about diesels.....
 

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Discussion Starter #7
I haven't seen a follow up and have been trying to do some research on it. I think the banjo connector you mention was part of the ALDA system. But I am not able to see the same type of connection on the manifold that I have been reading about. Is it possible that this does not exist on a 1991 350SD and is only part of the 87 and earlier 300 6 cylinder diesels? If not, could someone please tell me where to find it on my engine? I have not been able to locate it.
 

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Discussion Starter #8
ok, I found out that there is no banjo bolt to clean out on a 603, so that option is not there.
 
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