Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - TBI fuel delivery problem when starting
View Single Post
  #21 (permalink)  
Old 04-19-2013, 09:55 AM
oldbogie oldbogie is offline
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 6,437
Wiki Edits: 0

Thanks: 3
Thanked 331 Times in 288 Posts
Quote:
Originally Posted by fleetsidebob View Post
When I turn the key to the run position, the fuel pump runs for a couple of seconds and shuts off. I was assuming it stopped running because it was pressured up.

How can I test to see if there is actually pressure at the injectors during start up? I hate to disconnect fuel lines and have gas shooting all over the place.

The pump itself is not very accessable, but I'm wondering if I could use a clamp meter around the power wire to the fuel pump and see if we have current while the starter is turning. Would that make sense?
The pump should run from 10 to 15 seconds. What's going on is a pump shut down by the computer if in that time if the computer doesn't see the RPMs coming up from a sucessful start. Additionally, there is a relay on the firewall that can fail. You need to get a wire diagram to checck all this out. There are minor differences of how this curcuit is layed out that appear year to year, model to model.

If it's a sensing problem often the engine can be started with a prime and it will continue running, if it's a relay problem it will burn the prime then stop running.

You can force the issue by jumpering around the relay but then you've got to be sure that if the key is in run position, the engine better damn well also be actually running.

Bogie
Reply With Quote
The Following User Says Thank You to oldbogie For This Useful Post:
fleetsidebob (04-19-2013)