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Juan Crespo
Juan Crespo, ASE Certified Technician
Category: Chevy
Satisfied Customers: 1526
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
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2001 chevy 3500 6.5 turbo diesel no power after engine ts

Customer Question

2001 chevy 3500 6.5 turbo diesel no power after engine hits 160 degrees (will not go even 10 mph )
new injection pump,boost pump , turbo, remote pmd installed 400 miles before issue started .took to 2 mechanic suggested injectors after he timed injection pump and changed out map sensor .Installed injectors no fault codes mechanic
Submitted: 1 year ago.
Category: Chevy
Expert:  Juan Crespo replied 1 year ago.

Hi there.

I imagine there was a typo and you meant this is actually a 6.6L. Do you have access to a capable scan tool to use for our diagnosis - Tech-II or equivalent?

Customer: replied 1 year ago.
I do and no there are no codes I have a standard $200 scan tool I have a invoice from the one guy can I send it over so you can see all that has been done
Customer: replied 1 year ago.
mine is obd 2
Expert:  Juan Crespo replied 1 year ago.

I'm sorry, but, unless we're told up front, there is no way for us experts to know whether our customers are professional technicians looking for a little help, or DIY'ers who need a lot.

I'm sorry if I wasn't clear regarding the scan tool; I meant a scan tool equivalent to a Tech-II that could read engine and system data plus perform actuator tests, not just read codes. In this particular case, no-power on these LB7s usually means not enough diesel, so the first thing we would look at is MAF data.

Customer: replied 1 year ago.
ok my back ground aircraft mechanic for 20 plus years but my diesel knowledge is based on backhoes and front end loaders I am very smart when it comes to all mechanics just don't know what the parameters are I am looking at on this truck because I have no manuals
Customer: replied 1 year ago.
fyi if after you start this truck before the temp increases it runs fine
Customer: replied 1 year ago.
I can go down and fire the truck up and watch the maf data is that what you need
Customer: replied 1 year ago.
I have attached 2 thing for you to see we did find a sheared woodroof key on timing gear back when injection pump was changed out that is why we took to a guy that works on these type motors that is his invoice
Expert:  Juan Crespo replied 1 year ago.

I'm sorry, your reply came before I could post my response.

Please monitor what happens to the cam sensor signal once the engine warms up. In these engines, the onboard computer uses the crank sensor signal to start and run in basic mode; then, once the engine warms up, it looks to the cam sensor signals to fine tune injection.

If your scan tool can, please read injector on-time before and after warm-up to see if it changes in response to cam or engine temp signal.

Customer: replied 1 year ago.
ok I will if it does not I can drive it one mile to the guy that does my inspections on my fleet they do not work on diesels (tomorrow morning)and see what it says ill go run what I can right now
Expert:  Juan Crespo replied 1 year ago.

Looking forward to your next reply...

Customer: replied 1 year ago.
scan tool not reading and major data on that truck maf etc but does on my 2006 and 2000 chevys will attempt to update scan tool
Expert:  Juan Crespo replied 1 year ago.

The advantage of seeing the data on a scan tool is that it allows to identify and pinpoint the failure. Without that scan tool, we'd be basically left with process of elimination as the only recourse.

Customer: replied 1 year ago.
we called that shot gun trouble shooting (throw parts at it until you figure it out ) not sure if I will be able to put truck on the scanner at my local guys place they are busy today may need to do it tomorrow . did you have a chance to review the 2 items I sent as attachments ????
Expert:  Juan Crespo replied 1 year ago.

I did read the invoice from the repair shop. There was nothing in there that could help us diagnose the issue of no power after warm-up. Looks like we're back to scan tool or as you call it "shot gun trouble shooting"...

Customer: replied 1 year ago.
good morning I took truck to local garage the machine we used is a snap on verus dio we attempted to do custom data for MAF or injector on time info no such sections there is a map it was at 29.2 is there a different name for injector on time (these injectors have no electrical connecting on them mechanical what is next
Expert:  Juan Crespo replied 1 year ago.

The way this injection system works, the onboard computer controls the injection pump as it meters, pressurizes and sends fuel to the eight nozzles.

I was hoping to see some kind of data showing how the system works when cold in comparison to how it works when warm. In other words, what changes from cold to hot that makes the engine run poorly. Is it metering, is it timing, etc.? Thing of it is, the only type of scan tool that I'm aware of that can "see" that kind of data is the Tech-II.

Customer: replied 1 year ago.
well this is big shop 8 bays and they do fleet trucks for the railroad should I take a picture of what the screen on there scanner tool shows they do emission on all vehicles in our state .I believe the unit cost like $8000 so it should show
Customer: replied 1 year ago.
ok spoke to the owner of the shop it is not a tech 2 so what is the next step ????
Expert:  Juan Crespo replied 1 year ago.

I'm sorry, but I only know how to diagnose these things using the right tools. I'll opt out and see if another expert can help you. Please don't reply until the other expert responds or the system will cycle it back to me.