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Hi I was changing all the seals and gaskets on my engine as a project and just to learn more about engines. I did all the gaskets and seals except head gasket (did not want to open a can of worms).
In order to replace timing cover gasket and seal I had to remove the synchroniser. Now I have a suspicion that when installing it back it was installed incorrectly and now when engine runs it has very very rough idle and vibrates alot. Inside the cab it sounds like an I am sitting on the engine. Also there is no much response on the accelerator. And occasional loud pop with fire coming out of the exhaust manifold. I think that timing is off, and in order to fix it I will need a special tool to install the synchroniser set engine to TDC on the compression stroke and try it again.
What throws me off a bit is that there is no any check engine codes being generated. Also I did not drive the truck to make sure I won't damage the engine.
So my question is my suspicions correct? what else can cause this kind of behaviour? Any help is very welcome.
p.s. the synchronizer does not control cam timing, it controls injector timing. It tells the PCM when cylinder #1 is on the compression stroke and sequences all of the other injectors off of #1. It's mainly for emissions but the mistimed injections really screw up the way the engine runs, apparently. Good luck.
p.s. #2 - if you get back in there check the bushing on the synchronizer. They tend to go dry and start chirping before they cause more damage. You can oil them and gain some life, but if it's dry and you're there you might consider replacing it.
Not all that important from a drivability standpoint
I see them all the time where the magnet has fallen away from the sensor atop the synchronizer
That destroys the metal half moon window on the shaft and the sensor goes inop
Only turns on the light mostly, with no drivability problems
Get the tool and set it correctly
Like the above post mentions, check the firing order (again)
Make sure your intake gasket and the isolator bolts are new
Check engine light is not on. Triple checked spark plugs wiring. they are correct.
Was trying some things today just observationally. I can really hear misfires on the intake side where the air filter is. Also engine won't rev up higher than 1877 rpm. Idles at 800 rpm.
Did some live logging using my obd2 scanner not sure if it is any useful yet.
at Idle:
Timing Advance for #1 cylinder 20.5 (ranged 15.5-20.5) degrees
Short Term Fuel trim Bank 2: 11.7%
Short Term Fuel trim Bank 1: 9.4%
Absolute Throttle position: 22.7%
Calculated Engine load Value: 25.9%
RPM: 812 rpm
Mass Air Flow Rate: 7.02 g/s
Another snapshot: with calculated engine load value: 98%
Short Term Fuel trim Bank 2: 21.1%
Short Term Fuel trim Bank 1: 32.8%
Also intake gaskets and isolator bolts are both new.
I ordered the tool to set the sensor.
manicmechanic007, so having that synchronizer installed incorrectly would not cause the issues I am having?
Your fuel trims show a big vacuum leal to the intake system. Or a dirty or malfunctioning MAF sensor.
And when you look at fuel trims you need to look at short and long combined. Add them together. Short term is what's happening now, long term is what the PCM had been seeing before. But both together is what the PCM is doing with the fuel supply.
Not sure what the limit is but that 32.8% trim is a giant correction.
If it was mine and I thought the synchronizer was off I'd unplug it and see what happens. If it was off nothing should happen, it it was right you should see a change.
Thank you for your reply. Okay, I will go tonight and unplug the synchronizer. Also I will run a smoke machine through the vacuum lines to see if there are some leaks. Anything else I can do while trying those two things?
I don't think so, sure sounds like you are lean
Mine (V6) same as yours. Turned out to be one injector that was not squirting fuel after I replaced all my intake gaskets and related isolator bolts
Just know the processor is adding fuel for the lean condition and I think the timing of the injector squirt is not the issue
I made a test injector firing apparatus and can monitor the fuel pressure as I fire each injector
That is how I found out one of my new Motorcraft injectors was no good and was the cause of all my problems
Code for lean bank 1 and O2 not switching (stuck lean O2) actually was stuck lean and was lean is why
Replaced that injector and the fuel trims cleared up (meaning less than 3 percent)
Then it passed I/M and I have been driving mine since
You could disconnect the CMP and see if a code shows up
I would like to see you actually time the cmp with the special tool and re try it anyway, just for GP's
I would replace the upper intake gaskets and the bolts (isolator bolts) they call the intake bolts
They come with the new rubber seals that are so common for leaking internally
When those isolator bolts leak vacuum, it's pretty hard to tell if not impossible, just the fuel trims and some hissing, sucking sound, if you are lucky
Cheap easy repair, if you have not done that yet, I would do that first
The PCV system has many potential leak areas. People apparently sometimes overlook the fresh air hose on the back of the big intake tube. The one that plugs in between the MAF sensor and the TB.
And from what I understand the MAF sensor has great power. The PCM places great faith in its readings.
But, going back to your live data, it seems impossible that you don't have a check engine light. I think that the lean codes will set very quickly. Did you look for codes? Maybe the light is burned out or has a piece of tape over it.
I also notice that your MAF sensor reading is off. 7 g/s at idle. It should be about 4 - 5 I think. I pasted one of my screens that I took for reference. I should have recorded engine temperature but I didn't. Might do another, good to have for future work.
Also odd that your idle speed is so low. Mine always runs up above 830. Oops, except in my screen shot.
Stuff to think about. Good luck.
Originally Posted by Noshpic
Check engine light is not on
Short Term Fuel trim Bank 2: 11.7%
Short Term Fuel trim Bank 1: 9.4%
Absolute Throttle position: 22.7%
Calculated Engine load Value: 25.9%
RPM: 812 rpm
Mass Air Flow Rate: 7.02 g/s
Another snapshot: with calculated engine load value: 98%
Short Term Fuel trim Bank 2: 21.1%
Short Term Fuel trim Bank 1: 32.8%
Okay, I did smoke test of the intake. Seems like one PCV valve rusted a bit and leaking a bit of vacuum, not enough to justify any of the symptoms I have. Also my ford is 2001, but the valve which is leaking only shows up in the 2002 4.2l engine. (https://www.rockauto.com/en/moreinfo...pt=5052&jsn=20)
I cleaned the MAF sensor, and seems like engine started to run better. but still vibrates. On the other hand it runs stable. Also did not hear misfires through the air intake anymore.
Also when I disconnected the Cam Shaft sensor, engine worked exactly the same as before (sensor plugged vs unplugged). The only difference I got a check engine light on that sensor is not responding...
Also CEL works fine, but not displaying any errors as of now, which would make my life much easier if it would. Hopefully tomorrow my synchronizer setter tool arrives So I can reinstall it, and see if it helps.
