Timing problem, need help.


pyralink
02-10-2010, 01:08 AM
I have a 2000 Isuzu Rodeo with a 3.2

I messed up the timing when I changed the water pump and now I'm having trouble correcting it....

Here's what I did to get it back; I turned both camshaft pulley's until they fell onto their aligment marks on the head. I positioned the crank pully mark to the mark on the oil casing, (the key is to the right)

I matched up the solid lines on the belt to the camshaft pulley marks, The dotted line on the belt matched up with alignment mark on the crank pulley.... Everything to the best of my knowledge is correct.

The only thing I'm not sure of is, whether or not I'm on the compression stroke, the crank should be at TDC by aligning the marks correct?

What's happening is; I get a hard jerk when the engine starts and a rough idle, The engine lights goes on when I accelerate and goes away when I let off, The code I'm getting is 1312, Control igniton or misfire....

Please advise... Thanks

Nick

XR400R
02-10-2010, 07:18 AM
Man, I hear ya. I did the same thing, but I was only a couple of teeth off so it ran, but very badly.

Here's the best advice I've found & used (verbatim) given by a former Isuzu tech who is truly a recognized expert (Jerry Lemond). It's a bit cryptic, but it saved my bacon, maybe it'll help you (it really stinks completely removing/replacing the timing belt twice in one day, I know!):

FORGET THE MANUAL , YOU CAN USE IT WIPE YOUR HANDS WITH WHEN YOU GET THRU, TURN THE CRANKSHAFT SO THAT THE KEYWAY IN THE CRANKSHAFT IS SET AT 3.0CLOCK THERE IS A LINE ON THE OIL PUMP TO LINE THIS ONE UP WITH, THIS ONE IS EASY THE SLASH MARK ON THE EDGE OF THE LOWER TIMING PULLEY GOES OVER TO THE 9.0 CLOCK POSITION, NOW ROTATE THE CAM PULLEY ON THE RT BANK CLOCKWISE AND IT WIL GO THUMP THUMP MAYBE 5-7 TURNS BEFORE IT WILL LINE UP , DEPENSD ON WHER IT IS NOW , LINE UP THE TIMING MARK ON THE PULLEY WITH THE MARK ON THE VLV CVR IT WILL BE RIGHT BETWEEN THE TWO SEALS IN FRT ALLSO THE KEY WAY IN THE CAM GEAR CAN BE USED AND IT SHOULD LINE UP WITH THE MARK ON THE PULLEY,, NOW ON THE LFT BANKTAKE A CLOSE LOOK AT THE TIMING MARK ON THE VLV CVR SAME SPOT AS ON THE RT BANK, LOOK TO THE LEFT OF THIS MARK FOR A MARK ON THE CYL HEAD ITSELF NOW ROTATE THE CAM GEAR AROUND WHAT EVER NO OF TURNS IT TAKES TO GET THE MARK TO LINE UP, WITH THE MARK ON THE GEAR AND THE CYL HEAD OK ,, NOW ROTATE THE SAME GEAR CLOCKWISE UNTILL THE CAM GEAR MARK LINES UP WITH THE MARK ON THE VLV CVR , THE REASON YOU HAVE TO TURN THES THINGS SO MANY TIMES, IS THE CRANK SHAFT OBVISOULY HAS TO TURN TWICE FOR EVERY CAM SHAFT TURN CORRECT WELL ON THESE ENGS THE RATIO FOR THE CAM TO CRANK IS NOT 2.1 IT IS 1.57 TO ONE , HOW CAN THAT BE THE RATIO IS PICKED BACK UP INSIDE THE HEAD WITH THE CAM GEARS INSIDE THE HEAD TO BRING IT BACK TO THE 2.1 CAM TO CRANK ,, THIS WAS DONE TO LOWER THE CYL HEAD HEIGHT , SOMETIME TAKE A LOOK AT THE OVERALL HEIGHT OF THIS ENG COMPARED TO THE OLD ER 3.2 SOHC OR THE DOHC ENG THIS ENG IS ALLMOST 3INCHES SHORTER IN HEIGHT , THERE ARE NO ROCKER ARMS NOLIFTERS NO ROCKER SHAFTS , THE CAMS RUN RIGHT ON TOP OF THE VLV STEM THRU A BUCKET TYP SDJUSTER THAT SITS ON TOP OF THE CAMSHAFT, NO A NEW DESIGN BY ANY MEANS BEEN AROUND FOR EVER BUT NOT IN THIS TYPE OF AN ENG ,,, ANYWAY NOW PUT THE BELT BACKON AND RELEASE THE TENSIONER AND YOU SHOULD BE IN GOOD SHAPE , BY THE WAY THESE ENGS WILL RUN ON 3 CYL ON ONE BANK RELATIVELY SMOOTH.

dclegg61
04-21-2010, 02:40 PM
Would being one tooth off on either the cam or crank cause engine to be hard to start. Engine spins quite a bit before it starts. but runs smooth after start. Gas mileage sucks.
This problem started a few days after I replaced timing belt, tensioner, & pulleys.

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