1999 Ford Explorer OBD-II Trouble Codes

Ford vehicles do not have a cold start injector...... quite common in European vehicles of the past (not sure about the present) as well as some older Japanese. Additionally, I would have to assume the reference to injector timing circuit would be the thermo-time delay associated with cold start injectors. I have no experience with the code reader you acquired, and it sounds like I probably wont...

Since your Ford??? doctors scan tool brought forth a temperature sensor code (I assume coolant temp?) and made no mention of the two previous codes, I'm left wondering. Be aware that one or two ECT codes will point towards long warm up times..... IOW, a faulty thermostat - obviously changing the ECT wont fix that. I wont pass comment on a "mechanic" that doesn't install new parts with due care and diligence...... he must certainly realize that he is dealing with his customers.... those people that feed his family and pay his rent.... Can't speak for anyone else, but my customers are second in importance only to my family. I can't stress the importance of additional formal training enough...... I know I certainly wouldn't enjoy the thought of someone getting their OTJ training on my car....

Lastly, the symptoms you describe fit in with a well known pattern failure evident on all flavours of the 4.0....... intake manifold leaks. When the motor is cold, gaps open up between the intake gasket and the two sealing surfaces.... this unauthorized air entry fools the PCM into thinking less air is entering the motor than actually is, leaning the mixture and causing rough running and stalling. Since the O2s are not up to operating temp, the PCM is not looking at their signal to modify the fuel delivery. As the motor warms, expansion helps seal the existing leaks bringing the idle fuel mixture into designed range, keeping the O2s from detecting any lean mixture conditions.

OBD2 was conceived to assist the automotive aftermarket..... The idea was that all cars would exhibit the same code(s) for the same conditions. A P0300 is the code for random misfires..... this is true for any make and model of automobile sold in North America, i.e. - a P0300 is the same whether it is a Pontiac GrandAm or a V10 FSuperDuty. But one very important point to remember..... this only works for codes considered 'emissions critical'. Any other computer controlled functions that do not deal with either tailpipe or evaporative emissions are usually proprietary and are not required to share any definitions with other marques. As you have seen, there are many code descriptions that do not fit a particular system. Occasionally, these *may* appear as "phantom" codes and will not usually set the MIL.

HTH.

Jim Warman snipped-for-privacy@telusplanet.net

Thanks for the comments. I was kind of wondering about that cold start valve stuff .... I had gone to some of the autoparts net pages, and I would do a search for a "Cold Start Valve" ..... but none of the websites had any in stock. Now I know why !!! Thanks for queing me in on that part of the problem.

I had a real fiasco with a Ford dealer about 2 years ago. I had just gotten the Explorer, and it ran fine in the summer months, but come winter, I kept getting a "Check Engine Light". I never owned a car with one of these "new fangled idiot lights before. Didn't even know how to get rid of it, other than take it to a mechanic or dealer. Anyway, first they replaced the Intake Manifold Gasket, said I had a leak there. Drove it for a few days..... the light re-appeared. This time they changed the computer. No charge for the computer, it was still covered under the warrenty. Just got charged for the labor. Again, a few days later my friend, the light, re-appeared again.

The Explorer did not run bad; it drove nice as usual, but I had since found out how to get rid of the "Check Engine Light" . I found out that if you disconnect the battery, it resets the light. I got tired of hit and miss service tactics (Guessing sounds more like it) and being charged for services that don't fix anything ........ That's why I went and purchased my CarChip OBD-II scan tool, and prayed for warm weather to set in early !!!

So, I just kept resetting the light, and drove it until warmer weather came into season, and my troubles with the check engine light went away. But now, this year it's different. It won't idle when it's cold. It will run, but if you don't set in the auto, and tap the gas when it starts to cough and sputter, it will die. After it gets warm, it idles fine again.

Thanks for the help >Ford vehicles do not have a cold start injector...... quite common in