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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: jjb on July 19, 2016, 07:01:52 PM

Title: 8V92TA stalls at idle sometimes
Post by: jjb on July 19, 2016, 07:01:52 PM
I have an 8V92TA in a Military truck that stalls occasionally once warm. I also notice it will run rough at highway speed almost like its not getting enough fuel. It idles very low and sometimes the tach reads 0. At cold start I get about 7-800 rpms.

Any ideas where I should start looking? I recently noticed some air bubbles in the racor filter bowl so I think the first order is replacing fuel lines but I'm not 100% sure this my whole problem as it seems fine when its still cold.

Its a military rebuild by Diesel Exchange. It has less than 300 miles on it.

I attached a picture of the truck its in. Not a Bus but I heard you guys on here are Detroit experts.
Title: Re: 8V92TA stalls at idle sometimes
Post by: pabusnut on July 20, 2016, 11:18:26 AM
Fuel lines would be my guess.  I had similar symptoms with my 8V71.  My mechanic discovered steel fuel line rusted  through -- pinhole above axle.
Title: Re: 8V92TA stalls at idle sometimes
Post by: DoubleEagle on July 20, 2016, 05:14:26 PM
If air is getting in, fuel could be leaking out somewhere. Check for leaks everywhere. Is the fuel filter current and fitting well? Fuel pump is another possibility.
Title: Re: 8V92TA stalls at idle sometimes
Post by: jjb on July 20, 2016, 06:08:18 PM
no fuel leaks that I can see. There are 2 filters and both appear in good shape. I plan to chang them when i get new fuel lines.

What doesn't make sense is when cold it runs fine?

When cold it idles at about 800 rpms. When it gets up to operating temp the tach shows 0 rpms and that is when it wants to stall. I have adjusted the no load speed and idle per the military manuals and no change.
Title: Re: 8V92TA stalls at idle sometimes
Post by: DoubleEagle on July 21, 2016, 06:49:13 AM
Post this problem in the general bus discussion area (this area is off-topic), you should reach more people then. If you are lucky, someone like Clifford (luvrbus) will respond. Unless your filters are clogged or you have old fuel, you have a deeper problem that the serious mechanics probably know about.
Title: Re: 8V92TA stalls at idle sometimes
Post by: jjb on July 21, 2016, 08:49:29 PM
Can it be moved there?
Title: Re: 8V92TA stalls at idle sometimes
Post by: DoubleEagle on July 22, 2016, 09:01:11 AM
Try posting a new message in Bus Topics, that will work. Title it "Need help with 8V92".