Comments on: How do you tell if the fuel pump is bad on a 1990 jeep cherokee larado jeep?

By: DJBLADE311

DJBLADE311 — Sat, 13 Mar 2010 07:26:55 +0000

it could be many things:

Choke vacuum kick setting too wide
Fast idle RPM too low
Fast idle cam index incorrect
Vacuum leak
Bad Fuel Pump

To check fuel pump:
1. Turn on the key to the ignition position but dont start the car
2. If you hear the fuel pump whining up for a second or two, the fuel pump motor is operating ok. Next step is to check the fuel pressure at the fuel rail if its fuel injected. If you have a carburetor, then you need to check your Carb’s Float Settings.
2a. If you do NOT hear your fuel pump kick in, then check your fuel pump electrical connections, fuses and also check fuel pump relay (located in power distribution center located under black cover in engine compartment
). The fuel pump relay should click when turning on ignition.
3. Remove the fuel pump assembly and make sure the pickup tubes and the supply lines are attached correctly.
4. Its also possible that you have a bad fuel pump even though its new and/or your fuel rail has blockage

By: Ray F

Ray F — Sat, 13 Mar 2010 06:41:10 +0000

Normally when they go bad they wont give enough pressure to try to start. The motor will just turn with no firing. You can check it with the fuel pressure gauge. That would eliminate the fuel system anyway… there could be many other things wrong with it though… from a clogged catalytic converter to a bad knock sensor to a clogged fuel pump. The trick it to eliminate the most common problems first. Check the filter, then the pressure in the fuel system…

By: Pedro S

Pedro S — Sat, 13 Mar 2010 05:43:28 +0000

you test it with a fuel pressure gage

By: olz431

olz431 — Sat, 13 Mar 2010 05:38:36 +0000

It could be… check the fuel pressure with a fuel pressure gauge