Re:07 ford explorer 4.0l

Did an in vehicle repair of the driver side timing chain, primary chain, and balance shaft. I used the special tools as required. After completing the job im having a harsh/violent start up. Almost like the timing is all off. Once starter it idles beautifully. In park the car revs just fine, However the car won't move out of its on way, it barely revs going up the road. It will also cut off sometimes when idling. When it shuts off its very violent like its being mechanically stopped. I went to to look at the cam/crank relation on my scope and wasn't getting a good cam signal (wish I took a pic). I disconnected the sensor and found no voltage on the positive wire key on or engine running. My ground looked good. This is a pull down design as far as I can tell. I started tracing back to the computer. While back probed at the computer and the sensor, I plugged sensor back in and picture below is what I found. Signal looks very weak, def low volts from everything else I've seen of other waveforms. My question is could this be my issue rather than a mechanical timing issue?

Back storey car was running great before and was simply getting chains because of a broken guide causing a rattle. I did turn the cams over independently of the crankshaft with the rollers in if it matters. Ik its not recommended to do so, but I've done it many times before ( not on this engine) without an issue. I was able to get the engine torn back down to the cams before leaving today and plan to check timing and attempt to correct if there wrong without pulling the timing cover. This is my first 4.0l ford engine repair. Anyone with some good insight?

Was there any resistance when you were turning the cams without the crank? I'm not sure. if this is an interference engine, but I watched someone bend valves doing it on a honda. There was definitely resistance in that case though, that he pushed through with a long wrench.

I tend to think a weak signal from. the sensor wouldn't cause this since a bad sensor wouldn't. To be sure you could unplug it, but I'd do what you are doing and check that timing, or do a compression or leak down test.

Nissan Technician

i have cracked 2 flywheels due to a similar situation. changed distributors on a 89 bronco 2. put it in and was adjusting the timing by hand by rotating the distributor and went a little to far out of spec on timing during cranking , it was a violent slam a few times. like the engine compression of the engine was slamming against the starter, happened about 3 times as i was trying to get it started. found out later that the force from the starter trying to turn over and the out of time engine opposing that force,( violently slamming) broke my flywheel.

Little update, pulled the engine down again and it was perfectly in time still. I was getting mixed answers weather a fault in the cmp circuit would cause extreme ignition timing malfunctions matching my symptoms. I decided to disconnect the coil and turn the engine over to rule out between mechanical issue or electrical. With the ignition disabled engine spins over normal. No violent/harsh cranking, which leads me to think my ignition timing is all over the place as well becoming so far advanced is forcing the piston back down before near tdc. Revs great in park ( a small stumble at the beginning, sorta like an older carbed vehicle). Took it for a drive and it has zero power and won't rev at all, I did notice I had less spark advance with more throttle than I did with idle part throttle.

Again I still have no voltage on the feed wire to the cam sensor koeo or koer, sensor disconnected or connected. I previously called this circuit a pull down, im not sure if thats correct. I do know its a hall effect sensor (as per fords description). It looks like the pcm feeds the cmp a reference voltage as well the ground. Im assuming the sig return on the blueprint refers to ground. The ground is shared amongst many other sensors. The power is fed directly by pcm without being shared. I think I'm right in thinking this is the "power" wire as well the wire the computer is monitoring to interpret its pattern. Any tips on how to approach this "missing" voltage? I've tried several different methods im just not confident enough in my knowledge of how this functions yet.

I don't want to sound insulting, but are you positive the plug wires are routed correct? Bank one coil is 1-2-3, easy. Bank two coil is 5-6-4. I've put them back together 4-5-6. :whistle:

The cam sensor is not an input to this waste spark ignition system. It is used for fuel injector timing.

I'm sure bank one plug wires are right. That's the only side I pulled off i left bank 2 connected the whole time. But I will double check. So I back probed at the computer and found 1.4v on the reference wire and only 33mv on the wire at the sensor. So the cmp sensor doesn't control spark advance whatsoever? Is there anyway I can find this information on my identfix? Lol I never can seem to find information relating to what a sensor controls.

Yesterday started out still acting up, I was able to use my autel scan tool and manipulate the timing. Once I did that the vehicle ran perfect. I even drove it around. Unplugged my scanner and cut off/started the vehicle several times, zero issues. Then hours later I fire it up and its back running like crap.

When I verified timing I just pulled it down to the valve covers. I didnt account for slack in the primary chain which could be tensioned on the wrong time? That's my working theory right now and plan to tear it down again this morning and verify. My next question, I timed the balance shaft but what I found on the internet. Could an improperly timed balance shaft cause these kind of issues?