I have a 95 jeep wrangler with a 2.5 liter. At start-up the fuel pump will not run unless, I first go to the fuel rail test port and relieve the pressure, then depress the accellerator. The fuel pump will then run and the jeep will start. If the pump dose'nt run the jeep won't start. This appears to be the sequence of events in this order to make it run. I don't know where to go from here.
You mentioned this before, and it was a wacky and unusual thing before and it's still pretty wacky.
All I can think of is that it's a regulator issue (and the rail is running above the correct pressure) or a pump issue. I can't see how the control stuff could be causing it, but it wouldn't hurt to measure voltage at the pump and assure yourself that it's not a control problem.
--scott
When I hear of 'fixes' like you are doing, the first thing that comes to my mind is you are missing a ground. Pushing on the accelerator cable is completing the ground circuit so the relay energizes.
Jeeps are bad for getting punky body grounds. There should be a mesh cable crossing one engine mount and/or one running to the firewall from the engine and/or running from the battery to the firewall or fender.
Lots of the computer grounds bolt onto the block near the oil dipstick.
On the older YJ's the fuel pump ground was a wire tagged to the frame bolt of the emergency brake. There was a recall on some e-brakes and the 'technicians' are famous for forgetting to hook this fuel pump ground back up.
I use a booster cable to check for body ground issues. I run it from the battery negative to a bolt on the body to see if the symptoms change.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06
Wacky and unusual is why I'm strugling. After I didn't get any responses the last time I mentioned this, I went out and purchased the pressure regulator. I've not yet convinced myself that this is the problem so I haven't installed it yet. I guess for $60, I will go ahead and install it. I will also check voltage at the pump and check all grounds. My first thought on this whole thing was a ground issue. All of my connections had seemed to be tight but I didn't try running a new ground. Thank you for your thoughts!
"mack" wrote in news:1171622638.597304.55750 @l53g2000cwa.googlegroups.com:
"at first start-up".............meaning it starts w/out the ritual the rest of the day?? im assuming this jeep is TBI with a distributer...........kjun
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