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73-87 Chevy _ GMC Trucks => Performance => Topic started by: dirtmod0 on April 23, 2009, 06:37:08 pm

Title: gas engine deiseling??
Post by: dirtmod0 on April 23, 2009, 06:37:08 pm

Engine is a Vortec 350 with alum. Edelbrock intake and a Carter 650 electric choke carb. Every once in a while it it will diesel on me, very annoying. I have intial timing at about 18 degress and 32 at 3000 rpms. I run 87 octane maybe should run 89 or more? spark plugs are 44 long reach AC Delco r44lts.

What are your suggestions, I checked to see if carb was leaking after shutting off but didnt see anything.

Title: Re: gas engine deiseling??
Post by: TexasRed on April 23, 2009, 07:55:00 pm

What's the idle speed and is the choke operating correctly?

Title: Re: gas engine deiseling??
Post by: exilous on April 23, 2009, 08:59:36 pm

does it diesel for an extended period of time after shut off? or is it just a quick half second burst?

Title: Re: gas engine deiseling??
Post by: VileZambonie on April 23, 2009, 09:49:49 pm

Check your idle speed first.

Title: Re: gas engine deiseling??
Post by: dirtmod0 on April 24, 2009, 05:33:42 am

I will check dont have a tach. now that u mention it it seems to idle up sometimes and after putting in park after engine is warm, what would cause this? before I leave for work this morning I will tweak the choke a bit and see what happens.

Title: Re: gas engine deiseling??
Post by: VileZambonie on April 24, 2009, 07:21:29 am

Make sure it's completely off of the fast idle cam when the choke is open.

Title: Re: gas engine deiseling??
Post by: gold84gmc on April 24, 2009, 07:26:10 am

my engine used to do that....so i lowered the idle and now it doesnt do it anymore so i would check that

Title: Re: gas engine deiseling??
Post by: dirtmod0 on April 25, 2009, 06:08:47 am

I am thinking its getting stuck on the fast idle cam, I am gonna turn it a bit and maybe put a little grease on it to let it slide easier.
Thanks guys!

Title: Re: gas engine deiseling??
Post by: VileZambonie on April 25, 2009, 07:53:07 am

Make sure the choke is opening all the way and the fast idle screw is set properly.