Help with Carb on computer truck (now wont start at all)

[TacosnBeer]

You need to check the voltage at the coil when it is failing.

I will get a meter today and check it. By hot-wiring the Distributer to the ignition, that eliminated the ECM so, should have eliminated any voltage drop from the 12v supply. When I did that, it didn't change anything. I tried clearing the codes and revving it again and it bogged out the same as always.

I just got a box from summit today... new carb and PFR with a return line. I dont want to change too much at once till I narrow it down. To be honest, from what I know of the PO trouble shooting (2 carbs, 2 distributers) the only thing that wasnt changed is the FPR. I am going to try and change that this weekend and plumb the return line.

Any other ideas....

My vet is about 20 min past the Naalehu Bakery. Thats cool!

 

[Pinger]

Can't remember if this has been covered but is the EVAP (the thing that sits between fuel tank and inlet manifold still present? It's under ECU (PCM) control I think.

 

[TacosnBeer]

Can't remember if this has been covered but is the EVAP (the thing that sits between fuel tank and inlet manifold still present? It's under ECU (PCM) control I think.

Yes, the EVAP Canister is still there. There is a hose going to it but I have not traced it back anywhere to see if it is still hooked up down the line. what are you thinking?

It has an aftermarket intake for the carb and I have to check when I get home but, I don't think there is an EGR valve. Again, not 100% but I dont recollect seeing one.

 

[TacosnBeer]

EVAP Canister is there and hooked up to the tank but, there is no EGR valve which is likely why its popping the code.

You must be registered for see images attach

 

[Pinger]

Yes, the EVAP Canister is still there. There is a hose going to it but I have not traced it back anywhere to see if it is still hooked up down the line. what are you thinking?
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First thought was as the vertical pipe usually connects to the inlet manifold and anything amiss there could create a vacuum leak - but yours has been disabled there.

Don't know enough about EVAP systems to know if they can influence fuel pump operation. Probably not but seeing as you've nearly exhausted all other sources.... Have you tried hotwiring the pump?

As an aside my evap cannister doesn't have that additional part piggy backed to it. Mine only has a vent marked 'AIR' which vents to atmosphere where yours has hose connection to that additional thing. Mine was probably built to 'export' spec - possibly the reason for the difference.

 

[TacosnBeer]

First thought was as the vertical pipe usually connects to the inlet manifold and anything amiss there could create a vacuum leak - but yours has been disabled there.

Don't know enough about EVAP systems to know if they can influence fuel pump operation. Probably not but seeing as you've nearly exhausted all other sources.... Have you tried hotwiring the pump?

As an aside my evap cannister doesn't have that additional part piggy backed to it. Mine only has a vent marked 'AIR' which vents to atmosphere where yours has hose connection to that additional thing. Mine was probably built to 'export' spec - possibly the reason for the difference.

I honestly don't know much about EVAP systems to be able to troubleshoot that aspect without some help. I am down to try though. Anything to get to the bottom of the problem. I am getting a steady reading on the FPR gauge so, I don't think it is affecting the fuel pump.

 

[TacosnBeer]

Maybe this will help. Had to enlist my youtube channel to post this....
Here is a video of revving it with the bog showing vacuum as it happens. Is the vacuum supposed to go that low?

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[Supercharged111]

Sounds like a tuning issue to me. Get a wideband on there and get it jetted properly. It really only sounded like it did it that one time.

 

[TacosnBeer]

Yesterday my new carb and FPR came in.

I replaced the carb and she ran smooth. Took it for a drive and no bog, I just needed to adjust the TV cable for the transmission. So, I took her home, adjusted the cable and crawled underneath the fuel tank area to take a look. The fuel gauge has been bouncing around and I checked all the other grounds. Anyway, I saw a ground strap hanging from the bed right under the fuel filler on the inside of the bed. I hooked it to the screw that goes through the filler neck. Thinking awesome.. hope that helps. I start it up and she runs for about 1-2min and dies as I am backing her up. WTF now? Now, she turns but doesn't even sound like she wants to start.

I checked, there is power going into the HEI, there is spark at the plug, and the battery had plenty of power. I had someone start it while I watched the FPR gauge and it just sits at zero as the motor is just turning.... Crap. Could that ground strap have fried the fuel pump? The fuel pump is new too. I checked the fuses too, nothing burned out.

 

[Pinger]

Is the vacuum supposed to go that low?

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On the over-run, probably yes.

Sounds like a tuning issue to me. Get a wideband on there and get it jetted properly. It really only sounded like it did it that one time.

Like the there was fuel initially - then not.
Is the float chamber keeping up?