3rz-fe cam position sensor help

[Durogaff]

Ok guys, need help bad.

Been trying to research this myself but after hours and hours I'm still a bit unsure.

So, a couple of months ago I bought a Hilux of a friend for an absolute bargain but its got a weird midrange acceleration hesitation. It's good at low throttle and flat out.

He'd recently thrown in a low km replacement engine out of a wreck cause he drowned the original one and popped a few important bits out the side.

Anyway, he sold it cheap cause it never ran right. He'd already spent too much taking it to mechanics but nobody could determine the problem. Although i dont think he actually took it back to Toyota. One of these local mechanics actually tells me after I bought it, "it'd be a good thing as long as I could live with the engine issue." I guess he thought it could never be sorted. To me, it all sounded like bs.

So anyway, I replaced all the basic stuff, like new fuel filter, plugs and wires and plus fresh oil and filter. Cleaned the air flow meter with co contact cleaner, checked for vacuum leaks, checked egr valve, engine temp sensor and fuel pressure reg. All seemed ok and problem was no different.

Bought a replacement throttle pos sensor and then air flow meter, still not really any difference but fuel economy def improved after the new afm/maf.

Finally I decide to take it to one of my local mechs and ask him to pull the error code for me, an hour later still couldn't get it.

****** at the world, I finally decide to buy a service manual. An hour flicking through that and I finally get a code.

Right, it's cam position sensor. Replace that and then I'm fixed. But no. Fail!

Error 12 is still coming up, which is cam pos sensor. Even after clearing codes, same. The hesitation is still there but it's a lot less savage.

So a few days ago I see my friend again and he decides to tell me the replacement engine isn't outta a Hilux, it's from a Prado. Also, alledgedly it was a dizzy model not coil pack/electronic ignition, and he got it cheap with no manifolds or sensors. Now apparently, distributor run engines dont have a cam pos sensor in the head. So to put his original sensor back in, he got a machine shop to drill the head out for the sensor and mounting bolt.

Now, I can only hope that they've drilled this in the correct vertical position. It does look about right compared to a few photos I've seen on the net, but it doesn't look like they've machined the face of the head where the sensor seats. On further inspection with the rocker cover off, the cam pos sensor does seem quite a way from the lobe. Probably about 4mm. This sorta seems a lot for magnetic ac type sensors but I'm just guessing.

Does anyone know what the air gap between the camshaft position sensor and the lobe on the cam is meant to be?

Other auto brand forums say anywhere from about 10thou to 80thou of an inch. But I can't find an air gap figure for a 2.7 3rz-fe sensor or even any figure from any Toyota sensor. I'm thinking if its too much gap the voltage will be wrong. So i could possibly get the head machined to bring the sensor closer to the cam lobe.

Also any other ideas are greatly appreciated. If this isn't the fix, I'm gonna be outta ideas.

Thanks, sorry for the novel.

Edited March 23, 2013 by Durogaff