79' Shitbox wont start

[Odoyle]

79 cranks fine, rebuilt the 32/36, its getting fuel, starts really rough only for a second, pulled the distributor and I'm thinking the issue has to do with spark. Here is the distributor, a piece is missing off it, not sure if this would contribute to my issue, I'm considering getting new mag pickup and new ignition control module and go from there. Any input is much appreciated.

[azruss]

I don't think that would be the issue. Did you pull a plug wire and see if it would arc to ground. I would do that first to confirm you have no spark.

[131]

The missing piece is simply a bush that holds the counter weight up so it doesn't drag, allowing it to swing out and advance spark as the revs increase. It's not your issue.

[Odoyle]

Thank you for the feedback, I pulled all the plugs, sandblasted them and tested for spark by cranking while holding the plug near the head and got a nice arc. Now onto fuel, replaced the filter in the engine bay and took out the fuel sending unit in the tank and removed the sock which was crumbling. When I crank the motor, it doesn't seem like the fuel filter is filling up enough, could it be that the mechanical fuel pump isn't producing enough psi?

[bluespider262]

Bypass the gas tank and see if it pumps normal. Just run the inlet of the pump to a 5 gallon gas can via a few feet of 5/16" fuel line.

If the sock crumbled the hard line in the tank can be plugged with all the rust particles that are floating around in the tank.

If it works off the gas can you are going to need to clean out or replace that tank. Been there, done that.

[Odoyle]

Tested compression yesterday and got this:
1 - 120 PSi
2 - 121 PSI
3 - 85 PSI
4 - 118 PSI
The numbers aren't great, but these should be enough for the motor to run, right?

Tested the mechanical fuel pump as well and found:

Pressure leaving the pump was right under 5 PSI


Vacuum pressure on the inlet side was 14 Hg.


Those seem like acceptable figures, though I'll let you all confirm or deny that.
So I have compression, I have a spark, and it appears that I SHOULD have fuel pressure, so its either a carb issue or something in the fuel tank/hard lines.

Could anyone find a link which explains how to properly adjust a 32/36 DFEV carb. Thanks guys
In the mean time, I'll take bluespider's suggestion and try to bypass the fuel tank.

[Odoyle]

ALSO, checked static timing, everything lines up, just replaced ignition control module and stole the battery from my 83 and it cranks really well and sounds like it wants fire. Every 5-10 cranks I hear a pop and there is a mist of fuel shooting out of the top of the carb.

Float bowl has gas in it, but the fuel filter doesn't seem to get very full, new mechanical fuel pump on its way... also some blue sealant putty seemed to be stuck inside the pump, presumably from when the PO installed it last, may or may not have any influence on its operation.

[Shadoobie]

If you're still interested, this has been the best tuning guide for Webers by far http://www.redlineweber.com/html/Tech/c ... _best_.htm I also have a '79 with the DFEV upgrade. hope you get your problem sorted!

[Nitrate]

That subject box description just slayed me. I just does not get more perfect than that. God I was laughing for 10 minutes. Good one. RB

[RRoller123]

Cam timing? Was belt changed?

[Odoyle]

Cam marks all line up, just installed new mechanical fuel pump and checked some of the vapor lines before I try starting it and found a clogged check valve near the rear axle. I cleaned it out and it appears that I can blow air through both ends, one having slightly more resistance than the other. Not sure if that is correct or the valve is bust, so I got a new check valve that is one-way and will install it and see if that changes anything.

[lglade]

The check valves are supposed to be TWO-WAY to allow vapors to be collected in the charcoal canister and to allow make-up air to flow back to the tank. If you got the valve from one of our trusted vendors, then you should be fine. But one from eBay may not work as intended.

[Odoyle]

I hear what your saying, earlier today I called AR and asked about a two-way check valve, but said they only sell a one-way valve and seemed confused when I told them it is supposedly a two-way valve. Bought a German made one-way valve from a classic car parts store down the street, should the end of the valve which allows air to pass be pushing air towards the tank or to the charcoal trap? Also, looks like someone deliberately put some putty under the gas cap to close the small vent hole on the cap.

[RRoller123]

Just redid this recently with all the fuel lines. It is a 2-way valve, one side requires somewhat higher pressure than the other. The flange goes towards the tank side.

[AriK]

The 79 also has a one way check valve that goes in the return line near the carb. There must have been some confusion on which valve you need to replace. AR carries that one as well.