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2007 mp7 wont start


MackMan88
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new engine in truck. runs for about 3 secs then shuts down with no warning lights or anything. have fuel pressure, nothing blocking air pipes or anything like that. when it shuts down its as if it loses fuel and or combustion, after the shut down I can crank it but it wont fire. if I let it sit for 30 mins then try again it fires up then dies within a few secs. im at a loss of what to do now.

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Ive seen guys mix up the fuel lines on the fuel pump when swapping engines.

Maybe the cam timing sensor and crank timing sensor wire connectors are mixed up? I cant remember if that would kick a code or not. Just something to check since they can be mixed up easily.

Did you reuse the VEB/engine brake solenoid? Does it have an engine brake? Ive installed a few engine brakes and had bad VEB solenoids straight out of the box. Truck starts, oil pressure builds, defective VEB allows oil to pass, which activates engine brake shutting it down. The few seconds could be the time it takes to build oil pressure before the shutdown.

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hey there thx for your reply. fuel lines were removed with the pump. so they couldn't have been mixed up. crank and cam sensors are good. but we were thinking about the engine brake just like you said, because if the exhaust valves are forced open we would have no compression. and probably no start. so looks like I am pulling a valve cover off in the next few mins. oh and also snce I posted this. I removed the intake to check for a rag or anything like that. also checked to make sure the turbo wasn't blocked either, ill update on what I find after I pull the cover.

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  • 2 years later...

Hate to drag up an old thread but this was a first for me. After changing out the VEB solenoid on an mp7 the other day, had the same start then die issue. After reading this thread I swapped the old solenoid back in and she runs fine.

So apparently bad VEB's right out of the box appears common.

Edited by steeler
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  • 3 years later...
On 9/15/2021 at 3:40 AM, Madre said:

I got a Mack granite 2007 is running after 30 min die very hard to restart the truck

Both gas filter,fuel pump ,replace the timing sensor

still do the same time

Model Cv713

Bro in your case You may have injector/ injector cup issues ! yet another thing that can cause a fuel hard start issue a lot less evident on The earlier engines, but can happen! usually presents it self after working hard for several hours! you  shut off to fuel up / have lunch!  then have to prime it to start!

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