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Re: Getting gas to the FPR but no Injector spray - THNX Posted by RS [Email]  (#15)  [Profile/Gallery]
(more from RS) on Wed, 2 Feb 2005 19:53:35
In Reply to: Getting gas to the FPR but no Injector spray - THNX RS!, Rocket900S, Wed, 2 Feb 2005 17:20:58 Members do not see ads below this line. - Help Keep This Site Online - Signup |
That is odd, but not unknown. The way the FPR works is that, when the pressure is too high, the diaphragm pushes away from a seat and bleeds the excess pressure back to the tank.
The vacuum hose gives the FPR a reference to the pressure in the intake manifold. That lets the FPR keep the pressure in the fuel rail 3 bar (or 2.8 or 2.5, depending on the FPR rating) above the pressure in the intake manifold. That makes the calculations for injector pulse width in the ECU a lot easier.
Did you loosen the bolt on one of the fuel rail fittings and have gotten some fuel spray? Or did you jumper the fuel pump fuse?
Now it's time for some electrical detective work. With the fuel pump fuse jumpered and the key in the run position, check for voltage at the fuel pump terminals. You'll need to take the spare tire cover off and pop out the large round cover on the floor between the rear wheels above the fuel pump to access the terminals. You shouldn't be getting less than 10 volts or so. And it should be making some noise. If you're getting any voltage at the pump, give it a rap with the handle of a hammer. If it starts running, the pump is on its last legs. If it is running when jumpered and you then turn the key to the start position, the car should start. If it doesn't start under that condition, then you probably have a clogged fuel filter. (BTDT)
To check to see if you're getting injector pulse when you crank the car, you'd want an LED unit called a Noid Light. It plugs into the injector electrical connector
Also, check the grounds on the front engine lifting eye, right behind the AIC valve. All of the ECU grounds, including the grounds for the injectors are right there
Here's another possibility that I just remembered: I helped a fellow trace a similar problem on his '87 last year. He got stranded in South Carolina. We all talked him through the whole run of diagnostics and never quite got it right. He ended up tracking it down to a loose bulkhead conector, which joins the interior wiring harness to the fusebox through the driver's side kickpanel.
Here's a link to what he found:
http://www.saabnet.com/tsn/bb/900/index.html?bID=260804
, Wed, 2 Feb 2005 16:45:13, Wed, 2 Feb 2005 19:53:35 <-- Viewing This Message
, Wed, 2 Feb 2005 21:02:07, Thu, 3 Feb 2005 04:51:42, Thu, 3 Feb 2005 12:18:32, Fri, 4 Feb 2005 05:32:56
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