• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

EFI Start Issue need help

pcf_mark

Bronco Guru
Joined
Jun 11, 2010
Messages
3,611
Even if both pumps run for 2 seconds it is not enough. On my truck the pressure goes to zero as soon as I shut the engine off. The regulator must be leaking (pump is nearly new). I have to cycle the key three times to get enough fuel for a clean smooth start.
 

POPPAWS BRONCO

Full Member
Joined
Jul 12, 2011
Messages
233
Loc.
Horn Lake, Ms.
I run the FAST Ez EFI 2.0 direct port injection so I have fuel rail. When you turn the system on the in cab screen boots up and you hear in tank pump (in tank) turn on. After 3-5 sec it shuts off when system sees its has achieved regulator pressure 43# when pump shuts off it drops to 29# (I have a return system). When cold typically cranks in 2-4 seconds and only after pump catches back up, then will go dead. Second crank fires right up and settles into a high idle (1250)and slowly comes down to 900 as set in system. Always takes two cranks when cold. Stock 302 no mods other than EFI and ignition system.


Hey!!! Let me hold a dollar I'm in the middle of a restore here!
 
OP
OP
DEEPWOODS

DEEPWOODS

Contributor
Bronco Guru
Joined
Jul 29, 2007
Messages
1,100
Yes pumps are wired correctly. It runs great after starting . Pumps only run two seconds at most when you turn key on. It does not hold any pressure even if you cycle key to on 4 or 5 times. What sensor tells the computer it did not start and cuts the pump off? Next I am going to check the high pressure pump it must have a check valve that's not working or stuck open.
 

EFI Guy

Sponsor/Vendor
TheEFIguy@gmail
Joined
Apr 14, 2013
Messages
1,074
Loc.
BFE
The PCM primes it when you turn the key to on. After that, it turns the pump on when it gets PIP signal from the distributor (Cranking). Once PIP stops (engine at 0 rpm) then it shuts the pump off.
 
OP
OP
DEEPWOODS

DEEPWOODS

Contributor
Bronco Guru
Joined
Jul 29, 2007
Messages
1,100
I pulled the HP pump off and the check valve is stuck open.I don't see any to get to it so I ordered a new Bosch 69100 fuel pump recommended on here I hope this fixes the problem.
 
OP
OP
DEEPWOODS

DEEPWOODS

Contributor
Bronco Guru
Joined
Jul 29, 2007
Messages
1,100
I got the new pump and stainless steel pump mount installed today and it now holds fuel pressure after you turn it off. It is cranking now first try! Thank all of you for your help with this,Thanks again Keith
 

Attachments

  • IMG_1047.jpg
    IMG_1047.jpg
    89 KB · Views: 20
  • IMG_1048.jpg
    IMG_1048.jpg
    94.5 KB · Views: 22

BoulderMike22

Jr. Member
Joined
Sep 26, 2013
Messages
99
Great news! Glad you have it running...now you can actually enjoy EFI!


Sent from my iPhone using Tapatalk
 
Top