Picked up a super nice 03' as is with a no start. It cranks over nice and smooth, sounds like it has proper compression, and has proper fuel pressure. Tried spraying either in it and it will almost catch.

Tried putting a known good coil pack on it, no dice. Usually when other engine slip timing chains, it will crank rough, like a few cylinders are zero. This is not the case.

Any ideas?

 

anyone?????

 

Have you checked for spark? Easy to do, and will tell you quite a bit.

If there is no spark, consider changing out the Crankshaft Position (CKP) sensor.

-Rod

 

There is spark. Engine sound like it wants to start, but it will not catch.

 

If it has spark, why did you put a known good coil on it? Do you suspect the spark may be weak?

As you're probably aware, the engine needs the proper air:fuel ratio, compression, and spark at the correct time to start and run. Since you've tried starting fluid and confirmed it has spark, it seems like compression is the next thing you need to confirm. But it would certainly would help to know that the fuel is good and the pressure is within specification.

Was there anything atypical that lead up to this Explorer not starting, such as sitting for several days, hitting a large pothole shortly before pulling in your driveway, finding a mouse in your garage, etc.?

-Rod

 

It was purchased as is from an auction as a non runner. We heard it crank and the engine sounded good so we did not beleive it was slipped timing components. I have heard plenty of 4.0L SOHC engines that have jumped time and you can hear the cylinders that are flat by the sound of the starter.

This sounds like it is flooded, which it is. But putting new plugs in just refouls / wets them. The spark looks ok but i don;t know if is in the correct time.

How do you check the cam / crank sensors on a scantool?

 

With a higher end scan tool you can check the CKP and CMP sensor readings to make sure they are getting a reading, and that it seems reasonable. The more fool-proof method is with an oscilloscope to make sure you are getting a nice clean square wave from each.

-Rod

 

Are the plugs wet from water/coolant? I was chasing a no-start on my Accord. It would almost catch and start and prior to that was rough at startup for a few seconds. When I pulled the plugs, one was wet with what I thought was coolant, but also still smelled a little like fuel because it wouldn't light off. The top of the piston had a wet sheen to it when I looked at it with a flashlight. I vacuumed it out with a shop vac (don't do this if you have a lot of fuel in the cylinder or you'll get flames) and it started up. That didn't fix the problem but confirmed the presence of coolant was the cause.

 

Make sure you do not have Diesel or water in the Fuel Diesel is a bear to overcome. If you mix a small amount of gas with diesel it will always smell like gas.
I would also make sure the crank shaft position sensor is working proper as well the cam shaft position sensor.
Oh yes take a Ohm meter and check some of your plugs to ground if there is contamination in the cylinder it will read resistance or short depending on the setting.

 

Have you found anything worth listing to.

 

The purpose of codes is to point you in the right direction. Got any? Other than that, an inexpensive vacuum gauge will tell you alot.

 

Plugs are wet with fuel only. No diesel. Crank sensor and cam sensor are reading something but I cannot graph them to see if they are erratic. Cheapo autozone scan tool.

I would be willing to buy one new sensor and unplug the other for troubleshooting purposes. Which one can I unplug and still have it run? I know the PCM needs only one to at least fire.

 

Don't unplug anything just change the crank shaft position sensor I have ben bitten more than ounce by that bug it always sounds as if it will crank on the next turn.