General P0351 & p0352 intermittant start & other problems !

[03jg0304]

Hi everyone

On my sisters seicento 2003 we had the cambelt replaced and at first it didn't start at all and turned out the bottom pulley wasn't done up tight enough, this was then sorted
Then when you went over a certain speed the engine light flashed, engine detected a random misfire as the timing pulley was out ever so slightly, it has now been moved and this has cured that problem

But now every few days or so the car starts up on first attempt and then cuts out, it Turns over but won't start only on the 4th attempt it will start them comes up with the fault codes, but it runs fine, htc leads have been changed and the crank sensor too, any ideas?

Like I said the car runs fine and it's strange how it happens every few days and starts on the 4th attempt

Any help much appreciated

 

[blu73]

well the codes mean the ecu thinks there is an issue with both coil packs...

First thing to try would be double check all the connectors are pushed right on and clean, all the ht leads at coils and plugs, and the coil pack wires are on properly - you have the right way round or it wouldn't run but they might not have a very good connection.

 

[woj]

Wait. What do you mean the bottom pulley was not thight enough? Which bottom pulley - the cam belt one or the auxilary one?

Also, did you do the phonic wheel relearn procedure?

 

[03jg0304]

I'm not sure the mechanic said it had come slightly loose after cambelt change and that was the reason why it wasn't starting at all, but he's changing the crank pulley as we speak.

I tried the phonic wheel learn myself without any software connected etc

 

[woj]

The crank pulley has a locking pin which, when the pulley is loose, is almost certain to snap. When snapped all kinds of "miracles" will be happening, ECU codes being only a particular manifestation of these.

 

[fingers99]

:yeahthat:

It's quite possible to end up with infinitely variable valve and cam timing! They seem to be of a relatively primitive sintered manufacture, so the (part of the crank pulley) faux woodruff key is prone to snapping off.

 

[blu73]

my pin snapped off on my turbo years ago, so long as i make sure its right way round its never been an issue, never had an eml come on. And it just wouldn't run if it wasn't the right way round but the OP states car runs fine so it must be right way round.... I always forget the phonic relearn thing the mpi's do though.

Whereabouts you hail from 03jg0304? Might be a member nearby that has a copy of MES which will make it do the relearn rather than the hold revs at whatever it is however many times, i read so many different numbers for this and it seems a bit hit and miss.

 

[fingers99]

Ah, you're thinking of the pip on the alternator pulley, Woj and I are thinking of the cam pulley.

Mind you, I can't think of a sane reason to undo the main crank bolt to do a mere cam belt swap!

 

[blu73]

ahhhh, gotcha - this is an mpi thing i take it, well cam position sensor pickup point on the pulley?? I really must mess with some mpi sei's at some point!!!

 

[woj]

Mate, you are not paying attention

 

[blu73]

Mate, you are not paying attention

The crank pulley has a locking pin which, when the pulley is loose, is almost certain to snap.

*cough*

 

[03jg0304]

I'm from Norwich mate, just seems strange it does it every few days and starts after 4 turns of the key

 

[blu73]

there is a few members i know of down that way, whether any of them have software or not i don't know.

 

[03jg0304]

Just a quick update went to start the car after work and got the car back around lunch after the guy fitted a new crankshaft sensor and it wouldn't start at all, I unplugged the sensor cam plug and it started fine, left the plug off then wouldn't start again and then next min it's okay again, really annoying me now !

 

[Alfa Patch]

Does the car try to fire, misfire, or front fire? If so my car did exactly that when the crank pulley key sheared. It had completely variable timing so would work fine sometimes and be completely out the rest.

It had symptoms like the timing was out but inconsistently.

As fingers and woj suggest if that pulley was loose it will probably have sheared, they're made out of cheese.

 

[ycming]

Could this be because of the micro ecu ?? They are known to suffer from mis-firing problem?

 

[blu73]

is it the micro-ecu that gets fried if the coils fail? I know i have read it countless time but never having had one or messed with any mpi i can't remember..

 

[fingers99]

It is, but I'd not expect that car to run as well as it does if it were the ECU.

 

[blu73]

ah yeah, i'll get my coat.... again

 

[03jg0304]

The car runs fine with no misfires, when it starts it starts a bit dodgy now and again