QuestionQUESTION: Mr. Schwell, I'm not getting power to the fuel pump, main relay fuse and ECM(I THINK). This looks like the problem on this forum from 10/31/07 w/ Andrew. The car will not start.
ANSWER: Hugh:
Can you me more specific in your observations, for example:
a. are you getting power to the instrument panel?
b. when trying to start the car, does the engine crank?
c.Have you tried squirting a bit of starting ether into the air intake port just to see if the engine runs a short while? (This will eliminate lack of spark as a possible problem). Also, a good way to check the fuel pump circuit is as follows: (with the ignition switch off)
At the fusebox located over the left fenderwell under the hood,
a. Remove fuses 27 and 30
b. Connect a jumper between the inboard terminal of No. 27 to the
outboard terminal of No. 30. "Inboard" means the terminal
closest to the engine & "outboard" is that closest to the left
wheel.
If the fuel pump runs when only when the jumper if connected, the relay or wiring to the relay is faulty (which sounds like your description). If it does NOT run, then the problem is in the wiring to the pump or the pump itself.
Now comes the search for the bad connection..tedious but inescapable! Of course there may be other sources of the problem such as the control unit, or the ignition switch itself, but performing the above will be a good start.
Hope this helps,
Jerry
---------- FOLLOW-UP ----------
QUESTION: Sun., 5/3/09 Jumped #30 fuse and pump ran. Car would start and run for a few seconds on ether. Checked relays, I think they are good.(Two @ rt. wheel and 2 in rt. passenger side panel, any more?). Checked them by jumping power to the coil part and cking ohms. Also heard clicks. You mentioned "wiring to the relay", which wiring would that be? Shouldn't I be sure of the Bosch Jtronic and the ign. switch before attacking the wiring? How do I ck them?
Answer
Fuel injection system
Hugh:
Did you try to start the car with the relay running and jumpered? If that works, then we know for certain that the problem lies in the wiring controlling the relay or the relay itself.It is possible for the relay COIL to test ok (resistance, continuity, etc) but with the contact points defective. In all liklihood, however, the problem is somewhere between the ignition switch and pump relay.
Assuming that to be the case, then you will need to trace the fuel pump relay control voltage (+12V) back to its source. I am attaching a schematic to aid in this regard. Briefly, this signal comes from the main fuel injection relay, item 229, terminal #87. This relay is energized by a "logic low" signal originating from pin # 21 of the main fuel system computer module. This signal, in turn is based on a number of inputs such as the keyswitch, of course, and the ignition system (provides a retriggerable multivibrator type function) to sustain fuel pump operation. For now, I suggest trouble shooting up to the controller output, i. e. pin 21.
Also, for expediency purposes, you could "jury-rig" the fuel pump by using a toggle switch mounted in the dashboard, if you wish. That will, however, bypass an "accident safety function" which de-energized the fuel pump should the engine stop running.
Hope this helps a bit,
Jerry
