Its Not Starting

Anonymous · Post by **Anonymous** » Thu Jan 27, 05 12:16 pm

Ive recently upgraded my ignition system from dual points to a Chrysler magnetic pickup distributor along with a fresh MSD Blaster 2 coil, 8mm Moroso wires, and a MDS Digital 6 Plus unit and am not having any luck getting the 383 lump to start.

I had the reluctor and magnetic pickups all gapped to .080" (correct to spec), confirmed with MSD tech support that all the wiring and settings are correct, and am still backfiring through the carb.

Just so that you know, there is one other variable: at the same time, I also replaced the electric fuel pump (some old Holly rig with unknown flow/pressure rating), with a Holly Blue pump (including factory set regulator) to feed the Holly 750 double pumper.

And before you ask, yes Ive seen Dave's article on timing. Any ideas on this would be more than welcome.

Dave-R · Post by **Dave-R** » Thu Jan 27, 05 12:30 pm

Backfiring through the carb sounds like the timing out.

However, just in case...
Have you got a mechanical fuel pressure guage monitoring the pressure to the carb? If so what is it? Is the fuel bowl level set right?

Check every step of the timing set-up again just in case you are not firing on #1 plug tower in the dizzy or something or have the dizzy 180 degrees out. Easily done if you were at TDC on the exhaust stroke rather than the compression stroke.

Anonymous · Post by **Anonymous** » Thu Jan 27, 05 1:15 pm

Thanks Dave,

Before I had a dual friction clutch installed, I had the dizzy lined up with tower #1 at TDC. When he phoned this morning explaining he couldnt start it after 2 hours of trying (cash register ringing in the background), I explained that it could be 180 out of phase.

I havent yet installed a mechanical fuel pressure gauge or started finessing the carb, but suspect that if the fuel pump i installed had a higher rating than the one I replaced It would just run richer.

Dave-R · Post by **Dave-R** » Thu Jan 27, 05 1:50 pm

It would not run richer. It would flood the engine. Fuel pressure to the carb is VITAL. You HAVE to use a gauge.

Anonymous · Post by **Anonymous** » Thu Jan 27, 05 3:02 pm

The regulator that came with the pump had already been pre-set to approximately 14 psi, flowing 88 gph while maintaining 9 psi line pressure. Any idea what the guage should be reading if this needs to be adjusted at the regulator? Further info on engine spec includes: Weiand single plane manifold, .484 lift cam, duration unknown (Duncan might know), bored 30 over.

Dave-R · Post by **Dave-R** » Thu Jan 27, 05 4:07 pm

You want around 7psi at the carb with that sort of cam. 8psi will be OK just watch the fuel level remains just below the bowl plug level.

Anonymous · Post by **Anonymous** » Fri Jan 28, 05 9:33 am

Thanks for putting me on the righteous path, Dave

.

The only pressure settings I could find for my setup were quite vauge (4 - 7 psi).

Rich · Post by **Rich** » Fri Jan 28, 05 7:27 pm

Slightly off topic(sorry)What is the ideal fuel pressure on a fairly stock small block with a 600 Holley??

Guy · Post by **Guy** » Fri Jan 28, 05 8:11 pm

All holley's want between 5 & 7 psi they will run with 4 psi but will run lean when the secondarys open.

Rich · Post by **Rich** » Sat Jan 29, 05 12:37 am

Than Q.