Intemittent starting problem

[bob.dent]

Just recently I sometimes have a problem in starting, usually when the car's been sitting for a few hours or overnight  without running. My first thought was crankcase sensor but I had this replaced about a year ago, and the symptoms aren't quite the same. When the sensor last went, it wouldn't fire at all when cranking the engine, but this time it "coughs" but won't fire until after quite a few turns. When it does fire, the engine runs as smooth as silk and will then fire again on the first turn of the key.

When I mentioned this to my mechanic, he said it could be either crankcase sensor or cam sensor and would need to put Tech2 on to read the fault codes.

Any ideas?

[nixoro]

Could be an issue with the starter motor :-/

Have you tried to do the Paperclip test or has the eml not come on

[Bo Bo]

I've seen this before & think leaking injectors was the culprit?
If so I believe starting is made easier with the accelerator pressed (or pressed & released).

[bob.dent]

Could be an issue with the starter motor :-/

Have you tried to do the Paperclip test or has the eml not come on

Not being very technical when it comes to cars, I've heard about it many times on here but I'm not sure I'd know how to do the paperclip test.

The EML hasn't come on at all.

[nixoro]

Could be that the crank sensor is on its way out.

Had a camshaft sensor go had it replaced then 6months later it went again could be the start of the end for your sensor

hope that makes sense

[cdx25]

Your symptoms sound very similar to my crank sensor failure - ran fine once started, but was occasionally very reluctant to start.  Some coughs and spluts as it cranked.  Always ran fine after starting and never died on me after a successful start.  No EML on at any time which was odd.  Someone on here suggested that the wiring starts to fail when routed near the exhausts, and this can often cause a breakdown of the sensor output which is at its worst when battery voltage is lowest during cranking.  A kind of early warning I suppose, if you are "lucky" enough for it to fail this way.  A new sensor has returned all to normal for me - but I rewired it away from the exhaust.  Its possible yours failed early if wired too near the hot bits when it was done last year...

You need to get at the fault codes.  Mine showed a code 19 even though the EML was not on.

Jon

[old cruiser]

Might also be worth checking the connector pins on the coolant sensor also and the sensor itself  , if they are not mating correctly due to corrosion etc, the ecu might be getting somewhat confused about the engine Temp' and trying to give you a warm start setup as it were, rather than cold.
Cheers Pete

[Markjay]

I suggest that you compare your experience with that of Auto Addict and Taxi Driver, both are now well-trained in the art of soptting cam sensor failures...  

[bob.dent]

Thanks for the replies guys. I suspect it probably is the crankcase sensor again but wanted to run it by you guys in case these were symptoms of something more sinister. Last time it happened, the symptoms were slightly different in as much as the engine wouldn't try to fire at all when cranking, but this time it does "cough" or "splut" sometimes.

Car's going in for MOT in a couple weeks so I'll get them to check on their Tech2 if it holds out until then :-/

[Kevin Wood]

If it's leaking injectors try cranking it on a wide open throttle for a few seconds to clear out any fuel then start in the normal way. If this helps it may be leaky injectors flooding the engine when left to stand for any period of time.

Fuel injection ECUs normally enter a "flood clear" mode when cranked with the throttle wide open where they don't inject any further fuel.

Kevin

[Elite Pete]

I think you should pick the new car up earlier that way you dont have to worry about the car starting and you can come to Keswick  

[TheBoy]

Take the advice above (cranking for 5s WOT, then starting normally), as my initial reaction is leaky injectors...

[nixoro]

Could a partially blocked fuel filter cause this sort of starting issues :question :-/

[bob.dent]

I think you should pick the new car up earlier that way you dont have to worry about the car starting and you can come to Keswick  

I wish I could Pete, but at the moment the seller can't let it go until beginning of June. Also got to find a buyer for mine so will start advertising it soon, although I may have a possible buyer locally, but can't sell it it until starting issue is sorted.

[bob.dent]

If it's leaking injectors try cranking it on a wide open throttle for a few seconds to clear out any fuel then start in the normal way. If this helps it may be leaky injectors flooding the engine when left to stand for any period of time.

Fuel injection ECUs normally enter a "flood clear" mode when cranked with the throttle wide open where they don't inject any further fuel.

Kevin

Thanks for that Kevin (and Jaime) - I'll try it next time it happens. Hasn't played up yesterday or today so far.