AJP Firing order help

[Gray_101]

Hi, after adjusting my tappet shims on my 4.2 Ajp my even bank is running really rough, im not sure what ive done wrong, but i feel the camshaft timing has gone slighty out, So i want to check the timing.
Ive made a TDC tool out of the spark plug but im now stuck because i dont know the correct firing order.

my thanks in advance for your help guys

Edited by Gray_101 on Sunday 4th April 11:14

[itiejim]

Hmmmn, I've yet to see a definitive answer to this question when it has been posed before.

Given that the AJP is a flat plane crank engine, I suspect that each bank would fire 1-3-4-2 like virtually all inline fours (except Fords).

In terms of how to attach the HT leads - see the picture below (noting the position of the coil feeds).

If you only need to do the cam timing then really you just need to know when you are at TDC on each bank. When number 2 (and therefore also 8) is at TDC you should have equal overlap on cylinder 8. Then, you turn the engine the 75 degrees to get to TDC for number 1 (and also number 7) and you should have equal overlap at number 8 cylinder.

Without wishing to teach my granny how to suck eggs etc, just remember that you need to complete two rotations of the crank to repeat this situation as the cams rotate at 1/2 speed - I've confused myself with this in the past

[clive f]

I found that when doing the shims and re connecting the cams, I set up the even bank first, then the odd bank, but when you slacken the cam sprock bolts to adjust the overlap on the odd bank, the tension of the cam chain and the position of the even bank cam makes the chain move a very small amount, so after getting the odd bank set up perfectly, the even bank overlap is then wrong.

I stopped this happening by reseting the even bank, then before slackening the bolts on the odd bank I managed to put a screwdriver through the sprocket holes and rest against the top face of the timong cover and head so that the sprocket could not rotate when slackening the bolts.

[Gray_101]

Thanks for the advice guys , and after much checking, head sratching and more checking i think ive got it sorted, and the reason for all my trouble was id set the cam to the sprocket on some one else s scribe mark and not mine, so the cam was advanced about 70 degrees, no wonder it wouldnt run right.

Oh how i laughed when i figured it out ,,,,,,,,, not

ive just got ever thing crossed ive not bent a valve or 2,

needless to say i ll be checking ever thing again tomorrow before the inlet manifolds go back on and i attempt to start it

Edited by Gray_101 on Sunday 4th April 21:07

Edited by Gray_101 on Sunday 4th April 21:07

Edited by Gray_101 on Sunday 4th April 21:31