Vauxhall Owners Forum banner
1 - 11 of 11 Posts

·
Registered
Joined
·
13,676 Posts
Discussion Starter · #1 ·
right following on from my other thread about the car not starting when hot, so i replaced the crank sensor and it it all seemed fine, but i tested it in the evening when it wasnt so hot, buttoday when i got to work, i turned the car off and tried to start again it wouldnt, anyway got home and it did the same thing, plugged into the lappy and, cranked the engine and got a rpm signal from the crank(cranking at around 250-300rpm), every other signal it working fine, tps is at site 0, cts is reading as is air temp sensor.

one thing i did notce while cranking was the injector duty cycle was spking up to 100%, should this be happening upon cranking?

any ideas?
 

·
Registered
Joined
·
3,309 Posts
Sounds dodgey, what happens when the TPS fall off the bottom of the scale? does it flick to 100% cause it could be on the lower limit and jst flick forward and back of it, otherwise the cranking enrichment could be dodgey on th emap, but I assume the map is good?
 

·
Registered
Joined
·
13,676 Posts
Discussion Starter · #3 ·
i diddnt touch the throttle on cranking, i have never needed to as it starts fine, and the map was done by SBD just after the engine went back in.

also should of added, i went out last night stoped then started straight away, its only seem to be doing it when the outside temp is hot, all the thime its cooler its never been a problem
 

·
Registered
Joined
·
11,455 Posts
where is the CTS, and what temps was it reading when the starting problems occured ?

check the CTS trim map - sounds like heat soak probs to me - I used to get that - car would start, but idle lumpy, and misfire a bit until the air got moving through the engine bay
 

·
MIGClub Member
Joined
·
14,789 Posts
Is the fuel pump deffo running when it does this? The MBE ECUs usually run the pump for a few seconds when you turn the ignition on, so listen out for it. If not, possibly a relay. There should be two indentical relays on the SBD loom - try swaping them over and see if it makes a difference.
 

·
Registered
Joined
·
13,676 Posts
Discussion Starter · #8 ·
i did think that was an odd question Garylmao, the ATS is down behind the front bumper, i moved it there as i thingt it was the problem, it used to be just behind the filter, and it was reading a temp of 28 degrees behind the bumper

Mike - when i first turn the ignion on i can hear the pump prime and also see the fuel pressure gauge go up to,
 

·
Registered
Joined
·
11,455 Posts
ahha

probably the fuelling is way off then.

I have mine right *above* the air filter, and have never had soak problems since - when it was in the bumper, and also in the backplate when I ran a airbox, I'd get hot start problems.

though never so bad it wouldn't fire, but then start and run ok, that's where yours doesn't seem to fit - but you should still check.
 

·
Registered
Joined
·
11,455 Posts
if it did it then, and the symptoms now are the same, I doubt it's that tbh - it's too much of an on/off fault in that case.

the 100% duty cycle doesn't sound right at all, heat soak or not.

in the logs, do none of the other traces do anything strange when you get 100% DC ?

in fact, I've just remembered - the ECU does have a safety feature where 100% DC actually = 0 - it will not attempt to fuel run the engine when the limit is exceeded, which might explain the dry plugs.

does it stick at 100% for long ?, or is it just the odd spike ?
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top