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Engine cuts out in reverse

G

Goose57

Well-Known Member
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Location
Eureka Mo.
Hi all, I just got done w/ a new Optimizer build on my 95’ Duelly. It just started to cut out when backing up. Just a hiccup always in reverse. Never in drive. One time it did shut off. New 5521 IP, LP, known working PMD behind bumper, everything new. Any ideas? Thanks.
 
Bad motor mount/trans mount has shown me the two and twist differently in reverse than in forward. So when idle and going forward no issue but when loading them the other way :
Possibly pinched fuel supply or return line?
Possibly tension on wires disconnecting a little?
Possibly shorting wires getting squished?

Can you do a couple videos of it?
 
Really? I’ve never noticed anything that we didn’t find an issue to.
Can someone do a video?
If electronic then I would definitely jump to a harness somewhere ot being happy.

Now I wanna snag up one or two of the 6.5 trucks at work today and go play with it on break time & lunch at work today to see if I notice any difference vs the dmax. We get issued the truck we use so I’m in an 08.

But it died? That ain't right… would keep me worried about reliability.
 
Thanks guys. Yea I am concerned about reliability. I forgot to mention it also hiccups once or twice after start up too before moving the truck. I do remember on the old motor the hiccups coincided with the wait to start light blinking.Seems to only act up before it warms up. I’ll get under her and inspect all of the wiring and grounds. The only thing not new is the PMD and harness. They were working fine before. Maybe harness pinched somewhere. I’ll also check for DTC. I’ll try to do a video. Like I said it happens so fast it’s just a hiccup
except when it died one time. I’ll report back. Thanks again guys.
 
when you did the install, did you remove the noise filter that connects between the harness and the optic sensor on top of the IP. it's the large square connector on the top of the IP. the noise filter was something GM installed from factory, looks like a short harness adapter with a rectangular black box in the middle. those things are known to give issues. if you remove it from the harness and connect the harness straight into the IP it might help.

I'm sure someone here has a picture of it.
 
Thanks guys, I ran through the wiring shaking them while engine running and checked codes. No dice.


Watch the tach two little blips. I’m convinced it’s happing only on first start up cold. Like I said on the old engine it coincided with the wait to start light blinking. The light is not workin now I still need to troubleshoot it. On the old engine I always thought the blip and WTS lamp was the GP firing because it was still cold and not burning the fuel correctly💁. It doesn’t have the optic sensor any more. New upper engine harness going to the IP from Quadstar. New ECT,s It use to do it on the old engine too. I have two working PMD,s. I can’t remember which one I ran on the old engine. Maybe I’ll switch to the other PMD. Maybe try another harness too. Since the harness was on the old engine. Sure hate too spend the money. I shook the hell out of the extension harness too😂. Maybe I’ll put a fuel psi gauge in cab to see what’s going on on cold start up. I have a new Raptor LP coming 😎. Sure hope it’s not the ECM🙏🏻. Thanks guys for helping me. I’ll report back.
 
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