New motor dies during start up

Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.

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mikekurthy
Satellite Coupe (RL)
Posts: 6
Joined: Fri Aug 05, 2016 11:04 am
My Cars: 1972 Plymouth Road Runner

New motor dies during start up

Post by mikekurthy » Sun Oct 23, 2016 7:43 pm

In the process of restoring a 72 road runner with a stroked 400 (451). Motor was built by a pro shop (Indio motor machine).Motor was dyno tested and broken in. Upon start up, motor fires up then dies after about 3-5 seconds. No matter giving it gas or not giving it gas, motor would not stay running. Sounds good, running on all cylinders during those 3-5 seconds. The motor shop thinks I may have too much fuel pressure and I'm flooding the engine. I'm running a Holley 750. edelbrock 110 fuel pump (6 psi) and a fire core distributer. ,new engine bay harness. Everything is new on the resto. Anybody out there have this problem before?

dangina
GTX (RS)
Posts: 394
Joined: Sat Feb 12, 2011 12:28 am
My Cars: 71 roadrunner
Location: lethbridge, ab

Re: New motor dies during start up

Post by dangina » Mon Oct 24, 2016 3:44 am

congrats on the new engine! I just finished my 470ci stroker this year, sounds like your carb needs a tune. It also may be your distributor, I have the exact one and I just found out that the magnetic pickup came lose inside, I glued it back in but i think its loose again. POS. Looks like I'm gonna buy something else this winter...
400 stroked to 470ci, 3:55 Eaton true trac, slightly upgraded suspension lol

BUILD THREAD!!!! http://www.protouringmopar.com/showthread.php?796-1971-Speedipus-Rex&highlight=speedipus

mikekurthy
Satellite Coupe (RL)
Posts: 6
Joined: Fri Aug 05, 2016 11:04 am
My Cars: 1972 Plymouth Road Runner

Re: New motor dies during start up

Post by mikekurthy » Wed Oct 26, 2016 1:59 pm

I solved the problem.After speaking to the owner at Firecore, he referred me to a fellow in Canada named Ron.He informed me that I need to run a jumper wire from the 2 hot leeds (out of 4) that ran to the ballast resistor. With the key in the "run" position on my ignition switch, I wasn't getting 12 volts to to coil, that's why the motor was shutting off. I don't know why Firecore dosn't tell you this in their instruction sheet.

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