Mechanics

WILL NOT STAY RUNNING

1991 Isuzu Trooper • 75 miles

I just got an 4 cyl. Trooper. It has sat for 2 years. Have fresh gas, new battery. I can start it with ether. I dont hear a feul pump when I turn ignition on. But like I said it runs when I givwe itr a shot of ether. Any suggestions? Evry thing looks fines, Hoses (including Vacuum lines etc.
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Mkelee@cox.net
September 18, 2011.



Check fuel pump pressure. My guess is that it is weak and not strong enough to pressurize the system and start it. After started, it may produce enough to keep it running.

I JUST DONATED 5 BUCKS. I STARTED IT SEVERAL TIMES WITH ETHER AND IT WILL NOT KEEP RUNNING. I DO NOT HAVE THE EQUIPMENT TO CHECK FUEL PUMP PRESSURE. I DISCONECTED FUEL LINE AT TOP OF ENGING. AND AT FUEL FILTER THERE WAS SOME BAD GAS. I BLEW THRU AND IT WAS CLEAR. I PULLED FILTER IT WAS NOT CLOGGED. I TURNED THE IGNITION ON NO FUEL OUT FO TANK, I TRIED STARTING AND NO GAS PUMPED OUT OF TANK. SO I AM THINKING FUEL PUMP IS BAD.

Tiny
Mkelee@cox.net
Sep 19, 2011.
First, thank you for your donation. As far as the fuel pump test, go to this site for both directions and a video that shows how to check it. As far as tools, all you need is a fuel pressure gauge that most parts stores will lend to you.

http://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

I look at your article and read my service manual. I must test with the motor running to get a pressure. As I stated I can only get it to run with a ether shot, its not getting any gas to hold any kind of an idle for any period of time.

Tiny
Mkelee@cox.net
Sep 19, 2011.
When you first turn the key on, engine off, the pump should build pressure. I need to know how much it is building. Also, I need to know the engine size.

Ok its a 4 cyl 2.6 i-tec. I followed manual procedures. I disconnected the fuel outlet hose at the bottom of the regulator and connected the fuel pressure guage to the outlet hose. Turned the key on and nothing happened, turned motor over and nothing happened.

Tiny
Mkelee@cox.net
Sep 20, 2011.
Now check to see if the fuel pump is getting power. If it is, then the pump is bad. If there is no power, then you need to trace the power supply back checking for breaks n the wiring, bad relay.

OK I disconnected the fuel pump plug found I cold not make good contact with ends of wire at plug. I bared each wire (2) used a digital clamp meter turned to the setting w an ohms symbol (4000) put one probe at at each exposed wire and the meter sounded (ign on) I the used a test light (clamp attached to neg post of battery) probed each wire with ign. On but it did not light up. I then went to fuse block ther is 2 20 amp fuses one listed as fuel pump the other listed as fuel pump(st) with test light(circuit tester) clamp attached to the battery ground touched probe to each fuse and both times light lit. Found a 10 amp fuse listed as fuel pump relay coil(b)touch probe to this and light did not light up. I tried a new 10amp fuse and still did not light up. I am nat sure how to test relay. I also plugged fuel pump wires back together and turned ign on went to tank and did not hear anything.

Tiny
Mkelee@cox.net
Sep 21, 2011.
See if there is another relay with the same part number and switch them.

I switched with the a/c relay (Same part number) no noise at gas tank, the 10 amp fuse (fuel pump relay coil) still no light with circuit tester (clamp on neg. Terminal) ign. Was on

Tiny
Mkelee@cox.net
Sep 21, 2011.
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