EFI No Start

[cplynn]

I've been working on an EFI conversion and finally got everything in, but when I went to start my Bronco there's no start. Engine turns over, but does not start. I've read a bunch of threads on EFI no starts and I am going through the motions now, and I am at a point where I may have to drop my fuel tank and check on the pump. I REALLY don't want to do that, so thought I would pick the brains of you all.

#1 cylinder is on TDC

I am getting spark at the coil and the plugs, so I've ruled out a spark issue.

When checking the fuel pressure I am only getting 20psi at the rail and I know it is supposed to be up around 35-40psi. Also, the pressure drops back down to zero almost immediately and I know it's supposed to be more of a gradual drop.

In plumbing the EFI I was originally going to go with external LP pump, accumulator and external HP pump like I did on my last Bronco, but BC Broncos convinced me to go with an in-tank HP pump because it would work better with their fuel line kit, meaning the lines and unions in the kit are kind of designed to run a straight shot from the fuel tank to the fuel rail.

My fuel system is as follows:

BC Broncos EFI tank with high pressure pump inside the tank (BC Broncos assured me this would work)
BC Broncos EFI fuel line plumbing kit all the way to and from the rail
New 19# injectors
Explorer fuel rail

Please help. I really don't want to drop my tank!

[ZOSO]

check the fpr.

[cravenbronco]

check the fpr.

X2

[Viperwolf1]

The BC tanks are notorious for having loose fuel hose connections inside.

Instead of swapping out the fuel pressure regulator, just pinch off the return line to see if the pressure increases.

[cplynn]

I capped off the return line on the spring lock connector, just after the regulator and the fuel pressure still reads 20psi with the key in the "ON" position and the pressure still drops to 0 almost immediately when the key is turned off. So, am I correct in thinking this is pointing to the pump or pump to fuel line connection?

[Rox Crusher]

I'll buy lunch if it isn't the hose and / or hose clamps between the pump and the pick up tube

Only other possibility is a plugged filter but I am betting on the above

Sorry

[cw2054]

You might check you throttle position sensor I had problems with those before. Just a thought before you drop the tank.

[B.O.B.]

I'm with viper. Check the hoses in the tank. If you are getting a strong fuel smell it could be leaking injectors. Min did that until I changed injectors . Could always pull a plug and see if fuel is getting in the combustion chamber.

[cplynn]

Finally got my fuel tank back in. Hose clamps did need to be tightened down more. So now the fuel pressure is no longer dropping instantly like before, but the pressure is not getting above about 24psi. Thoughts?

[Viperwolf1]

Pinch the return line to check the regulator. If the pressure shoots up the regulator is leaking. If it doesn't, the problem is on the pump/pressure side.

[cplynn]

I should have mentioned I did pinch off the return line and the pressure did not go up. I don't know if just turning the engine over would create enough vacuum to draw fuel in the regulator vacuum line (if that was the problem), but I checked the vacuum line and there is no fuel in it. Maybe I'll just replace the regulator and see what happens.

[Viperwolf1]

I should have mentioned I did pinch off the return line and the pressure did not go up. I don't know if just turning the engine over would create enough vacuum to draw fuel in the regulator vacuum line (if that was the problem), but I checked the vacuum line and there is no fuel in it. Maybe I'll just replace the regulator and see what happens.

According to your results the regulator is not the problem. Even if it had full manifold vacuum at the regulator the pressure would only drop to around 32 psi.

[cplynn]

Finally got a little more time to troubleshoot and it's looking like the pump itself is the culprit, which is disappointing because it's a brand new pump. Hoping to get a new pump this week then hopefully I'll be up and running soon after.

[Rox Crusher]

I have the original pump that came with my BC Broncos EFI tank.

It worked fine but was noisy as hell.

I can donate it if you pm me your address.

[cplynn]

Sorry Rox, just saw your reply today. Wish I would have seen it earlier because I bought another pump over the weekend and got it installed. I am getting more pressure now, but no more than 35psi. Is 35psi enough for the rail and injectors or do I still need more? I went with a direct replacement pump for a fox body mustang, but the specs are not near as high as the BC Broncos pump--51psi max pressure, 18gph max flow rating. Curious because my Bronco still ain't startin'.

[Viperwolf1]

It should run at 35 psi. Are you getting spark?

[cplynn]

I am getting spark. I'm going to double check to make sure I'm on TDC of the compression stroke on cylinder #1. I was confident I had it right but I'll check again.

[Viperwolf1]

I am getting spark. I'm going to double check to make sure I'm on TDC of the compression stroke on cylinder #1. I was confident I had it right but I'll check again.

Didn't I see this movie once before.

[cplynn]

It does seem eerily familiar doesn't it? Trying to remember the events leading to the ending because it was a while ago that I saw the same movie.