How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask HDGENE Your Own Question
HDGENE, Ford Senior Master/Diesel/Trans
Category: Ford
Satisfied Customers: 5635
Experience:  25 years Auto experience, Ford ,GM, Chrysler, Asian & European
Type Your Ford Question Here...
HDGENE is online now
A new question is answered every 9 seconds

Ford Explorer: I have a 99 ford explorer 4.0L SOHC that stopped

Customer Question

I have a 99 ford explorer 4.0L SOHC that stopped starting. It was cranking but wouldn't start. I check fuel pressure and OK. I pulled a plug and it was damp. Checked spark and it was erratic. Checked coil pack for cracks and put back together and it started. Runs very erratic and then starves out and dies. Checked OBD code and found all cylinders misfire. I threw a KPS at it (cheap $15), no change. Tested voltage to KPS and checked out ok. Tested primary and secondary resistance on coil pack. Primary OK, Secondary slight fall off on 3/4 by .1-3 KOhms from the other two pairings. Also had to dig a little on 3/4 to get response with meter. Checked voltage to Cam shaft Position Sensor and found it did not have the 1.5 volts supply to sensor. .06 to .05 volts. I pulled the harness from the PCM and checked continuity between harness connector and CPS and checked out. Ran 1.5 Volts with a AA battery through same path and did not get a voltage drop at the CPS connector so I think the wiring is OK.
I'm stumped!
Submitted: 2 years ago.
Category: Ford
Expert:  HDGENE replied 2 years ago.
Hello, how many miles are on this engine? There are no other codes just P0301-306? Base engine compression is ok? Sounds like it cranks over normally/normal crank speed? Is this equipped with a PATS antiitheft system and the red THEFT lamp proves out normally?
Customer: replied 2 years ago.
Hello, there are 182K on the engine. The only major items I have done to the engine was changing the timing chain tension er and guide late last year. The engine cranks normally. No other codes. I have not checked compression and was thinking of doing so, but it was running normally until it stopped. I'm not sure which anti them system it has. Where would I be able to find that info? I would assume it has whatever system they put in the XLT package as this is the model. The Theft lamp lights normally.
Expert:  HDGENE replied 2 years ago.
For a misfire of all six cylinders I would think either a weak spark,you said you tested the coil but didnt mention spark quality since the plugs were wet?The ignition coils do go bad commonly on any of the ford v6 engines.Spark plug could also be wet if compression is low engough not to fire. Thats main concern with these overhead cam timing chains, when they jump time they bend valves and loose compression
Customer: replied 2 years ago.
I only tested spark quality as an initial test to decide between ignition or fuel. One plug and was slightly damp. I looked at spark and it was erratic. Which is why I went the direction of KPS and CPS. Still what concerns me is that not voltage to CPS. Should I be following this path? Where would I go next after this? I can replace coil pack and see what happens.
Expert:  HDGENE replied 2 years ago.
If you had a cam position sensor issue, I would imagine it would set a code for it as a hard fault and you tested the harness so that should be ok. Id be looking for a good blue steady spark and injector pulse whch you should have with the new crank sensor.
Customer: replied 2 years ago.
I have good voltage into coil pack. I'll replace coil pack and see where it goes. Can i check back with you?
Expert:  HDGENE replied 2 years ago.
yes you can just reply back to this thread
Customer: replied 2 years ago.
Hello,No dice. the coil pack didn't change anything. I did a CPS test as well and the sensor checked out. The car runs but but erratic pushing up to 2000 RPM with a accelerator boost then after 5 seconds dropping to under 1000 RPM then wants to stall out unless I boost it up. It's missing for sure. I'm gonna run codes again and see what I see.
Expert:  HDGENE replied 2 years ago.
Run a key on engine off and key on engine running test besides just pulling memory codes
Customer: replied 2 years ago.
No codes as I had the negative battery terminal removed.Ill let you know more tomorrow. Thanks
Expert:  HDGENE replied 2 years ago.
No problem, gonna need to run it and see what comes up on a scan tool