Rough Running after Timing Belt Install

[thedutchguy]

They've got spark, they've got compression (190 lbs I think they said), but nothing is happening on that side. Can anyone here explain that one??? I'm baffled...

Place your finger on the injectors to"feel" if they're working. So that you're sure you've got fuel.
If you have: compression, spark and fuel it has to be a timing issue.

[psychos2]

THIS INFORMATION BULLETIN OUTLINES THE PROPER STEPS TO INDEX THE CAMSHAFTS WITH THE CRANKSHAFT FOR VEHICLES EQUIPPED WITH DIRECT ATTACK DOHC 3.2L / 3.5L V6 ENGINE. IN THE EVENT THAT CAMSHAFT TIMING HAS BEEN DISRUPTED, DUE TO TIMING BELT BREAKAGE OR CAMSHAFTS / CRANKSHAFT BEING ROTATED WITHOUT A TIMING BELT, THIS IS IMPORTANT PRIOR TO TIMING BELT INSTALLATION. *TT
Make : ISUZU Model : VEHICROSS Year : 1999
Service Bulletin Num : SB0014S001 Date of Bulletin: FEB 01, 2000
NHTSA Item Number: 614146

i found this in a previous post. this is what i think the problem is.the cams are not indexed properly. if you sign up for alldata you can get the info you need.it is 24.95. or try to get info from a isuzu dealer. shawn

[mbeach]

I couldn't find that SB at any of my (usually very good) sources.

I did find a number of references to "valve damage" in the event the camshafts and crankshaft were rotated independently. It's odd that valve damage can occur in a non-interference (free-running) engine however.

I also found some high-quality images of the correct method of 'capturing' the belt tensioner during timing belt replacement. I'll cross-reference my method with those methods already used in kpaske's efforts.

[kpaske]

I looked up that TSB/NHTSA item number (614146) at the NHTSA web site, and it refers to the Child Safety Seats.

Make: ISUZU
Model: VEHICROSS
Year: 1999
Type: ANY
Service Bulletin Number: SB0014S001
NHTSA Item Number: 614146
Summary Description:
AMERICAN ISUZU MOTORS INC. IS PLEASED TO ANNOUNCE THE AVAILABILITY OF TOP TETHER CHILD RESTRAINT SEAT ANCHOR BRACKET KITS FOR CERTAIN ISUZU SPORT UTILITY VEHICLES. THE USE OF THIS ANCHOR BRACKET MAY BE NECESSARY WHEN INSTALLING CERTAIN CHILD SEATS, WHICH REQUIRE ANCHORING TO THE VEHICLE WITH A TOP TETHER STRAP. *TT

This is actually the one I think you meant to direct me to:

Make: ISUZU
Model: VEHICROSS
Year: 1999
Type: ANY
Service Bulletin Number: IB00S005
NHTSA Item Number: 614139
Summary Description:
THIS INFORMATION BULLETIN OUTLINES THE PROPER STEPS TO INDEX THE CAMSHAFTS WITH THE CRANKSHAFT FOR VEHICLES EQUIPPED WITH DIRECT ATTACK DOHC 3.2L / 3.5L V6 ENGINE. IN THE EVENT THAT CAMSHAFT TIMING HAS BEEN DISRUPTED, DUE TO TIMING BELT BREAKAGE OR CAMSHAFTS / CRANKSHAFT BEING ROTATED WITHOUT A TIMING BELT, THIS IS IMPORTANT PRIOR TO TIMING BELT INSTALLATION. *TT

I'll pass this info on to the shop working on my VX and see if they can get the information. Worse case scenario I can shell out the cash to NHTSA and get it myself. Maybe this will solve my problem once and for all. Thanks Pyschos2!

Mbeach - Can you give me some more info about this valve damage you speak of? That seems odd to me too, as I've always heard that even a timing belt breaking at 60+ mph cannot cause damage to a non-interference motor.

[mbeach]

It really just added up to "...failure to follow these instructions can lead to valve damage..."

Sounds weird to me too.

[kpaske]

Well, the TSB solved the problem. Thanks again to Psychos2 for bringing it to my attention.

A word of warning to anyone who attempts to replace their timing belt by themselves... I don't know if this problem was resolved in the 2000-2001 models, but apparently the Timing Belt Replacement procedure outlined in the Isuzu Shop Manual can create this problem. While the manual states that you should remove the timing belt and rotate the cam shafts and crank independently, the TSB explicitly states that this SHOULD NOT be done. The end result is having to remove the heads and realign the gears to reindex the cam shafts. Neither the mechanic nor the Isuzu technician he spoke to could really explain why this happens, but the bottom line is if you are going to do this yourself, the marks should all be lined up by rotating the crank BEFORE the belt is removed, and NOT rotated again until the new belt is back on and tensioned. I know some others have had success doing this themselves using the manual procedures, but I know I followed the directions correctly and it wound up costing me several days of my time, the cost of the parts, plus over $300 to have this mess fixed. You've been warned!

[Joe_Black]

Glad you got the problem solved! Just goes to show, we all can still find more to learn.