Help! advise on 348 engine stopping

Just had 30k service done on 348 which has 90k on clock, had timing belt, tensioner bearings, belt tensioner, water pump, all hoses and valve clearances etc, Hills TOB.
Took car for 100 kms drive after service and running perfect. Coming onto freeway I changed between 2 and 3 rd gear (don't know if accelerator jammed or not) but i think engine revs did not back off when clutch depressed and engine revved high and then just cut out. I noticed no power (of course) and ignition lights come on as engine cutout. There were no bad engine noises or grinding metallic noises it just cut out instantly. I coasted to a stop and arranged tow truck.
So my questions, please excuse my ignorance and if my questions are dumb. Did the rev limiter cut engine out, how does rev limiter work in a 348, "cut off fuel supply"? Does it then allow engine to run again after revs drop, or does the ECU have to be reset to clear high rev fault and then it will run as normal again. I got car towed to mechanic and they checked timing belt still in tact, pulled spark plugs appears to be no damage to any of them and Able to turn motor over by hand.
Help where do I start, Clutching at straws. should i panic and start organising a large loan. What sort of things should i start checking before having to pull engine out again.

 

thankyou for your reply, is the reset for rev limiter automatic or do ECUs have to be manually reset. Is the rev limiter fuel cutoff the only protection against high revs?

 

I had car towed to same workshop as it was only coincidently 2 kms down road and they were open on the saturday, and i trust them implicitly and have always found themcompetant mechcanics. He is also quite concerned and apologetic. I only hope the 348 engine is bullet proof and something didn't just break, but as i said there was no noise just engine stop and ignigion lights on. there would have been some period between my reaction to engage clutch back in after engine stopped.Wher edo i go from here what do i start checking??

 

Hi guys, pulled engine out, can't take the risk and can better assess with engine on floor. Looks like the Timing belt has picked up on the main driving gear timing belt guard (the one we do the spot weld modification to, to stop it from flying off). The belt has picked up on the sharp outer edge (the egde had rolled over) but it didn't come loose because it was spot welded the belt rolled it over and a small piece came adrift. The belt has lifted up on the guard edge and spun back on in micro second I expect and back onto gear making timing 2 teeth out retarded, hence shutdown of engine. Having repair done to the gear made a new belt guard on lathe more robust and thicker, they will TIG weld onto main driving gear and refit. Then fit new timing belt and then turn by hand to do compression and leakdown test. So Don't know if there is valve or head damage, fingers crossed.
Thanks for comments and help regards Larry

 

Hi guys sorry no pics, as I'm working away again 700kms away from car each week lately and can't get pics. Mechcanic advises unpon checking there is excessive valvle clearances.I need to go for a walk and have a quiet meltdown gather my thoughts. Okay, its bad news lets move on, means pistons have kissed the valves, next step plenum and heads off to find out how bad. Going to need full set of valves from somewhere, can I say right at this moment I'm "not impressed". Will have to wait and see what damage there is to pistons and heads. Will try and get pics and post some. Looks like I've been caught by the dreaded timing belt fence on lower drive gear. More to come soon.

 

Hi Guys, update on timing belt bottom drive gear fence failure. Found 17 bent valves, sent heads away for refurbishment and have now just picked up the cylinder heads from the re-conditioners. They have been comprehensively overhauled, incl. all new valves, shim adjustments, machining, etc... I have the gaskets and will commence reassembly sometime next week. Only another week and I will be back on road. I will try and post photos but can't seem to copy and paste straight into the thread. will have to work it out and post pics of valves.

 

Please find attached picture of one of the reconditioned heads received back after refurb. I will put pics of damaged valves up in next couple days.
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thanks guys straight on to that bearing condition tomorrow. kind regards Larry

 

Hi guys please find pics of some of the bent valves and the repair that has been done to the da### drive pulley fence. (machined a new fence from steel billet but put a small chamfer on belt side of new fence. and then tig welded it all the way around on drive pulley.
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Hi guys a little bit confused, is this bearing you say to check item No 3 or item No 11 on attached Ricambi drawing 348 (1989-1992): Table 6 - TIMING - CONTROLS.
I think it is item No 3 up against the block of the motor, is that right?
thanks in advance Larry.
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HI guys, I am only just back from the Snowy Mts for a couple days. Sorry about poor updates. Thanks to 2NA, plugzit and Ernie for advice on bearing and belt alignment. Yep I have been concerned that I was only treating the symptons of the failure and not the root cause. To clarify the mechanic is also baffled as to why the timing belt came off, I had the tensioner and idler pulleys replaced and all appeared to be sound and fitted correctly (hopefully checking this bearing the brotherhood have mentioned may shed some light). The mechanic has advised that he will take full responcibility for the failure and is covering all costs even though he can't ascertain why the failure, so no cost to me but still I don't like NOT knowing what caused the problem 100kms after a major. Now that I have calmed down (needed a long walk at time of failure and ensuing weeks) but you know what I just need to move on and be happy to just have the car and everything ship shape again. I have been paying closer attention to what the shop is doing and being more involved, that said I'm an Electrical Fitter Mechanic so my knowledge is limited. BTW the price to date for the repair is $24,200 Australian. I will pay for the bearings that 2NA, plugzit and Ernie have advised should be changed and I'm considering those gearbox shaft nuts (that come loose I read somewhere, (must find the thread) being looked at before I get engine refitted.
Once again thanks for all the advise and help guys, this is a great forum. regards larry