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cplynn
Official CCB Member
Joined: Sat Oct 30, 2010 6:33 am Posts: 80 Location: Littleton
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EFI No Start
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!
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Mon Jan 09, 2017 11:10 am |
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ZOSO
Moderator
Joined: Mon Nov 15, 2010 5:58 pm Posts: 3906 Location: Henderson, Co
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Re: EFI No Start
check the fpr.
_________________ Rob
74 Ranger EFI351w, 4r70w, ARB 5.13 9in, ARB 5.13D44, and a bunch of other goodies. Best of all the family memories.
04 Mustang Cobra, KenneBell 2.2 feeding a lot of boost on E85. Tire shredding machine
New project: 77 Bronco Ranger, body work and more body work.
Very little left of a 72 durango tan explorer sport
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Mon Jan 09, 2017 12:21 pm |
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cravenbronco
Official CCB Member
Joined: Sat Apr 19, 2014 5:40 pm Posts: 916 Location: Bailey
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Re: EFI No Start
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Mon Jan 09, 2017 12:47 pm |
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Viperwolf1
Official CCB Member
Joined: Tue May 07, 2013 10:37 pm Posts: 1485
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Re: EFI No Start
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.
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Mon Jan 09, 2017 2:57 pm |
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cplynn
Official CCB Member
Joined: Sat Oct 30, 2010 6:33 am Posts: 80 Location: Littleton
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Re: EFI No Start
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?
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Mon Jan 09, 2017 5:41 pm |
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Rox Crusher
Official CCB Member
Joined: Sun Oct 10, 2010 5:36 pm Posts: 3980 Location: Roxborough Park, Colorado
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Re: EFI No Start
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
_________________ 1977 Sport, 351w OBDII EFI motor, 4R70W auto, 4:88 gears, ARB lockers, 3.5" suspension, 33" tires.
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Mon Jan 09, 2017 6:55 pm |
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cw2054
Official CCB Member
Joined: Thu Dec 30, 2010 9:51 am Posts: 4
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Re: EFI No Start
You might check you throttle position sensor I had problems with those before. Just a thought before you drop the tank.
_________________ 1968 Bronco 351W, NP435
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Thu Jan 12, 2017 5:07 pm |
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B.O.B.
Official CCB Member
Joined: Thu Nov 11, 2010 10:31 am Posts: 770
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Re: EFI No Start
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.
_________________ 71' bronco, np435 w/trailbanger, 302 efi, 35" KM3 on 17x9 Fuel Anza, warn xd9000i, cage arms, 5" lift
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Sat Jan 14, 2017 7:20 am |
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cplynn
Official CCB Member
Joined: Sat Oct 30, 2010 6:33 am Posts: 80 Location: Littleton
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Re: EFI No Start
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?
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Thu Jan 19, 2017 5:42 pm |
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Viperwolf1
Official CCB Member
Joined: Tue May 07, 2013 10:37 pm Posts: 1485
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Re: EFI No Start
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.
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Thu Jan 19, 2017 7:34 pm |
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cplynn
Official CCB Member
Joined: Sat Oct 30, 2010 6:33 am Posts: 80 Location: Littleton
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Re: EFI No Start
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.
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Thu Jan 19, 2017 9:24 pm |
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Viperwolf1
Official CCB Member
Joined: Tue May 07, 2013 10:37 pm Posts: 1485
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Re: EFI No Start
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Fri Jan 20, 2017 10:19 am |
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cplynn
Official CCB Member
Joined: Sat Oct 30, 2010 6:33 am Posts: 80 Location: Littleton
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Re: EFI No Start
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.
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Sun Jan 29, 2017 8:32 pm |
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Rox Crusher
Official CCB Member
Joined: Sun Oct 10, 2010 5:36 pm Posts: 3980 Location: Roxborough Park, Colorado
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Re: EFI No Start
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.
_________________ 1977 Sport, 351w OBDII EFI motor, 4R70W auto, 4:88 gears, ARB lockers, 3.5" suspension, 33" tires.
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Sun Jan 29, 2017 9:19 pm |
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cplynn
Official CCB Member
Joined: Sat Oct 30, 2010 6:33 am Posts: 80 Location: Littleton
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Re: EFI No Start
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'.
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Mon Feb 06, 2017 6:50 pm |
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Viperwolf1
Official CCB Member
Joined: Tue May 07, 2013 10:37 pm Posts: 1485
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Re: EFI No Start
It should run at 35 psi. Are you getting spark?
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Mon Feb 06, 2017 7:16 pm |
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cplynn
Official CCB Member
Joined: Sat Oct 30, 2010 6:33 am Posts: 80 Location: Littleton
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Re: EFI No Start
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.
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Mon Feb 06, 2017 9:13 pm |
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Viperwolf1
Official CCB Member
Joined: Tue May 07, 2013 10:37 pm Posts: 1485
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Re: EFI No Start
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Mon Feb 06, 2017 9:54 pm |
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cplynn
Official CCB Member
Joined: Sat Oct 30, 2010 6:33 am Posts: 80 Location: Littleton
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Re: EFI No Start
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.
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Mon Feb 06, 2017 10:33 pm |
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