Mechanics

STARTING PROBLEMS

1988 Jeep Wagoneer

Engine Performance problem
1988 Jeep Wagoneer 6 cyl Four Wheel Drive Automatic 175000 miles

My 1988 jeep wagoneer 6 cylinder has a random problem of not starting, usually after a trip somewhere like to the store or church. If you try again later (sometimes within 30 minutes, other times 1 - 3 hours later) it will usually start and runs fine. I have replaced the igintion module, fuel filter, cleaned the idle air control valve and EGR valve. I have read that the crank sensor is a problem on these models. Could that be the problem?
Avatar
Hammer13
June 6, 2010.




Hello,

If I am not mistaken that year does not have a Crank or a Cam Sensor.

With what you describe it sounds like the Ignition Control Module which is located on the passenger side wheel well.

.

Obxautomedic
Jun 6, 2010.
Please Post responses here in forum and not by email.

Thanks

Ok, doesn't show a Crank Sensor on that year. Howerver, yes it can cause the problem, the knock sensor can also cause the problem.

.

Obxautomedic
Jun 7, 2010.
Ok, Also when the vehicle wouldn't start did you check to see if you had spark going into the Cap and at the Plugs?

Also did you check for fuel if you have good spark?

.
AD

Obxautomedic
Jun 7, 2010.
Ok, according to specs the fuel pressure should be 31 psi and with vacuum line removed from regulator pressure should be 39 psi.

So, I would say you have a weak fuel pump.

Here is another test you can perform for comformation.

1. Remove cap from pressure test port in fuel rail. Connect Fuel Pressure Gauge (J-37730-1) to pressure fitting. Start vehicle. Pressure should be approximately 31 psi (2.7 kg/cm 2 ) with vacuum hose connected to pressure regulator.

2. Pressure should be 39 psi (2.74 kg/cm 2 ) with vacuum hose removed from regulator. If fuel pressure is not to specifications, check for kinks or restricting bends in fuel supply and return lines. Check fuel pump flow rate. Pump should deliver minimum of 1.06 quarts (one liter) of fuel per minute with fuel return line pinched off.

3. If flow is inadequate, check system for plugged fuel filter or filter sock. Fuel pump flow rate can be checked by connecting a hose to fuel test port on fuel rail and inserting other end in clean container.

4. To operate fuel pump, install a jumper wire into diagnostic connector terminals D1-5 and D1-6. Pinch off fuel return line to ensure that no fuel returns to fuel tank. If fuel pressure is still not to specifications and fuel flow is normal, replace regulator.

.

Obxautomedic
Jun 18, 2010.
Ok, Check for loose or bad wires in relay harness.

If all appear tight and in good condition check numbers on relay then check other relays for matching numbers and swap them out. Then start vehicle and see what happens.

Also Please reply to this post and not by email.

.

Obxautomedic
Jun 21, 2010.
I could hear the EGR solenoid click when forcing the fuel pump relay to close so I tapped the EGR solenoid, fuel pump picked up and everything is working fine.

I replaced the crank sensor and the vehicle is running great! Much better than it has in several months.

Tiny
Hammer13
Jun 22, 2010.
Great! Good Job.

If need anything else just ask.

.

Obxautomedic
Jun 22, 2010.

AD