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Slow to fire at startup and now a CEL with no codes

Black Boss said:
Not wanting to get off topic, but am considering the harness upgrade: were the cam sensors individually reversed or switched between cams?
They are not bank specific but are for intake/exhaust. We installed the grey one on top instead of the black one. Does this answer your question?

N0122500_250_zps7decfe78.jpg
 

Grant 302

basic and well known psychic
cloud9 said:
I did pop in a fresh set of plugs when the coils were out and the harness and sensors were at PRS being upgraded. This cranking issue predates that so at least I know it's not plugs. Wouldn't a leaking injector pop a code?

A really bad one would pop a code, but a small leak may not. I was only suggesting to look at the plugs as indicators of what may be going on, I don't suspect the problem to be with the plugs themselves. Since all that has been unclipped with the harness fix, I'd go over every connector again too. I'd also suggest checking all the pin/wire connections if it wasn't such a pain on modern cars.
 
We got the cam sensors switched around and it fired right up and no codes. :) VCT was working again too so that was good. Shut it off and restarted a couple times with no extended cranking :-\ That's a good thing but not sure it's "gone". We got halfway through the battery relocation so won't be starting it again until we're done....hopefully tomorrow night.
 
Just saw this post and my $.02 is that it is unlikely to be fuel rail/pressure problems. These kind of problems would seem to also mave some kind of manifestation at run time and not just start-up.

At start-up, the ECu is trying to get a good read on cam and crank position sensors - and I strongly suspect the issues is there. A lazy or weak sensor - particularly when the engine is cold is allowing a cranking (turnover) operation but delaying the "fire" signal.
 
CoolTechLLC said:
Just saw this post and my $.02 is that it is unlikely to be fuel rail/pressure problems. These kind of problems would seem to also mave some kind of manifestation at run time and not just start-up.

At start-up, the ECu is trying to get a good read on cam and crank position sensors - and I strongly suspect the issues is there. A lazy or weak sensor - particularly when the engine is cold is allowing a cranking (turnover) operation but delaying the "fire" signal.
Makes sense given how slow it was to fire when we had the cam sensors in the wrong positions. Seemed worse than what I was experiencing late last summer. I won't get much chance to really test it until we warm up about 60 degrees :( At this point I'm hoping the upgraded harness and sensors have solved the problem since it did fire pretty much right away last night after a couple restarts.
 
BOSS343 said:
Whats the final verdict?
It's starting normally again this spring although driving time has been limited due to this awful weather. The only changes are the upgraded wiring harness/connectors and battery relocation. I can only assume there was some kind of a connection issue in one of those areas that was resolved during the process of deinstalling and reinstalling.
 

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