What its doing and what I've done.
I have a '98 Eddie Bauer explorer with the SOHC 4.0L. It has 150K and is currently logging a DTC of P0171 and P0303 and P0305. This is narrowed down from 15 codes when I bought it. I have checked all the obvious and replaced anything wrong ie... Upper and lower intake, EGR gasket and valve, Repaired a broken vac line at the purge valve, Plug wires and Plugs. The truck runs and starts but misses badly at idle and has recently taken to stalling at idle.
Engine specs
Currently the motor pulls 17in-Hg with a slowly fluctuating needle. Compression is (dry/wet)#1 - 130/140, #2 - 140/143, #3 - 150/151, #4 - 125/145, #5 - 140/155, #6 - 130/140. Fuel pressure 30psi at idle and 40psi at 2000rpm. All the injectors ohm out at 17.3 to 17.8 ohms.
Suspect areas
I currently have three areas suspect.
#1. I can not get a vacuum reading at the EGR at higher rpm but can pull and hold vacuum in this circuit ie.. hand pump at one end and vac gauge at the other. I can also bypass the EGR solenoid and activate the EGR valve. I am supposed to get less than 1.8in-Hg at idle and am not getting a reading. I checked the EGR vac solenoid coil resistance and get 36 ohms also I can apply vacuum to the EGR source port with the supply port plugged and hear the vent bleed off fairly quickly. QUESTION IS! Why don't I have vacuum at the EGR? Is it related the the EGR vac solenoid?
#2. When I apply vac to the circuit going to the purge canister It will not hold, I would assume these are supposed hold vac, it bleeds off pretty quickly. I can remove the fitting and put a hand pump on one end and vac gauge on the other and pull vac and hold it. QUESTION IS! Is the purge valve supposed to hold vac? or is it like the EGR vac solenoid and vent to atmosphere?
#3. DPFE valve, (would like to go through that when I have a scanner that can see PID values).Other more insidious vacuum leak like cracked manifold or PVC leak (kicking my self for not just replacing it when I had the manifold off).
I would love some input on these items. I do know a lot about vehicle diagnoses but am very new to Ford and this motor. So if more info is needed please ask and I will either get the info for you or look at you stupid. i know I have a vacuum leak but need help in knowing where to look. Next on the list of things to do is a leak down test as I, really don't want it to be but, think it could be a bad valve in each cylinder misfiring.
Found bad coil tower on #5 and severally clogged injector on #3. Replaced with junk yard injector and new coil and it drives like it should.
I have a '98 Eddie Bauer explorer with the SOHC 4.0L. It has 150K and is currently logging a DTC of P0171 and P0303 and P0305. This is narrowed down from 15 codes when I bought it. I have checked all the obvious and replaced anything wrong ie... Upper and lower intake, EGR gasket and valve, Repaired a broken vac line at the purge valve, Plug wires and Plugs. The truck runs and starts but misses badly at idle and has recently taken to stalling at idle.
Engine specs
Currently the motor pulls 17in-Hg with a slowly fluctuating needle. Compression is (dry/wet)#1 - 130/140, #2 - 140/143, #3 - 150/151, #4 - 125/145, #5 - 140/155, #6 - 130/140. Fuel pressure 30psi at idle and 40psi at 2000rpm. All the injectors ohm out at 17.3 to 17.8 ohms.
Suspect areas
I currently have three areas suspect.
#1. I can not get a vacuum reading at the EGR at higher rpm but can pull and hold vacuum in this circuit ie.. hand pump at one end and vac gauge at the other. I can also bypass the EGR solenoid and activate the EGR valve. I am supposed to get less than 1.8in-Hg at idle and am not getting a reading. I checked the EGR vac solenoid coil resistance and get 36 ohms also I can apply vacuum to the EGR source port with the supply port plugged and hear the vent bleed off fairly quickly. QUESTION IS! Why don't I have vacuum at the EGR? Is it related the the EGR vac solenoid?
#2. When I apply vac to the circuit going to the purge canister It will not hold, I would assume these are supposed hold vac, it bleeds off pretty quickly. I can remove the fitting and put a hand pump on one end and vac gauge on the other and pull vac and hold it. QUESTION IS! Is the purge valve supposed to hold vac? or is it like the EGR vac solenoid and vent to atmosphere?
#3. DPFE valve, (would like to go through that when I have a scanner that can see PID values).Other more insidious vacuum leak like cracked manifold or PVC leak (kicking my self for not just replacing it when I had the manifold off).
I would love some input on these items. I do know a lot about vehicle diagnoses but am very new to Ford and this motor. So if more info is needed please ask and I will either get the info for you or look at you stupid. i know I have a vacuum leak but need help in knowing where to look. Next on the list of things to do is a leak down test as I, really don't want it to be but, think it could be a bad valve in each cylinder misfiring.
Found bad coil tower on #5 and severally clogged injector on #3. Replaced with junk yard injector and new coil and it drives like it should.
