|
Hi Bill. He said he checked it against cyl #1 TDC. Steve (OP) said he pulled the timing covers, plural, like he was doing a belt change. I'm not sure why he would loosen all the drive belts and pull the harmonic balancer to get the lower timing cover off. If you do cyl #1 TDC and the pulley marks are aligned to the lower cover timing zero mark then all is well with the harmonic balancer and crank sprocket alignment and no need to get at the sprocket to check for a broken key.
As for a jumped timing belt tooth, you'll usally get rough running, not a sudden stall out. Even two jumped teeth and you'll still stumble and run. Jumped teeth are usually a sign of a misadjusted tensioner or a badly worn tensioner pulley. With the upper timing cover removed, a belt that's looser than normal, especially on the exhaust side, is a sign of misadjustment. The other possibility we worry about is a stripped belt tooth. The belt would normally be well beyond its change interval and a close inspection would reveal rubber fractures at the base of the teeth (there should be zero evidence). I've never used a cheap aftermarket timing belt (only use Continental) so don't have experience if other brands have a higher failure rate.
Normally when there's a sudden stallout at speed, it's the CPS. But there wouldn't be spark or injection during testing. The OP said he put in a known good CPS, meaning used. A used CPS may have been working okay prior to removal, but during removal, handling and re-installation the cable can crack -just happened to my old spare CPS, leaving me without a spare when the installed one finally went.
The CPS coils rarely if ever fail, it's the wiring or shield that breaks after years of flexing and stress, typically evidenced by damaged cable insulation, like a stress fracture way down at the bellhousing, at the mid-cable plastic standoffs, or scuffing against the return pipe to the water pump or the EGR to exhaust manifold pipe (if the standoffs are missing). When suspect, I normally remove the cable for a proper inspection and flexing it at the usual stress points (if it's borderline, that usually splits them). For aftermarket CPS, the only CPS I trust to have Volvo quality wiring and cable insulation are Bougicord (France, supposed OEM, now a global manufacturer, eg. Mexico) and Facit (made in Italy, looks really well made, my goto CPS now). Facit is apparently an OEM for BMW and Mercedes.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
|
