LS7 start up

[mark999]

jan 1st tried to start my LS7 for the fist time NO JOY did all the fuel pump pressureizing turned it over got oil pressure then tried to get her going. Just fires and cuts out any idea what i must be doing wrong,anyone..

[mt308]

mark999 said:

jan 1st tried to start my LS7 for the fist time NO JOY did all the fuel pump pressureizing turned it over got oil pressure then tried to get her going. Just fires and cuts out any idea what i must be doing wrong,anyone..

I am no expert here - mine fired up first time.

The fact you have fuel pressure and it does fire up before dying suggests to me possibly an electrical issue. Perhaps stating the obvious but double check all your wiring loom connectors are properly connected.

Good luck!

Mark

[Steve_D]

Does it cut as you release the key from the start position?

After it has died but without switching the ignition off check that the wires that are supposed to be live still are.

Steve

[mark999]

thanks for the quick replys trying everything plugs arnt wet it fires drops to 1000 rpm then just stops push start and its the same just not run,,

[Quinny]

Could be a relay issue.....as far as I know 1 relay primes the pump when the ignition is switched on, then once started another relay provides feed for the pump....

Maybe a problem with the second relay??

[macgtech]

Sounds like a fueling issue of some description. The tank return from the regulator is plumbed to the underside of the regulator, with the inlets to the reg (from the rail) plumbed in either side? Check the pumps are running when it fires too.

[pilbeam_mp62]

Check the obvious first - How much fuel do you have in the tanks ? I remember a LONG thread like this a while ago, where it turned out that there wasn't enough fuel in the tanks....

[mark999]

thirty ltrs in each tank going to check pumps are running tomorrow thanks for the help let you all know how i get on cheers mark.

[Magic919]

Can you scan it for error codes?

[mark999]

dont know how to start to scan it for the problem bit of a novice to the building of cars do what i can tomorrow and let you know..

[mt308]

Magic919 said:

Can you scan it for error codes?

I have an LS7 with the standard pin socket. I have a connector that I use in my Seat Leon which uses standard VW software that I bought online for less than £20.

Does anyone know of cheapish software for the LS7?

Always nice to do a scan every year or so on my Seat to see what comes up. And its never been wrong with the odd issue over the years.,,,

Thanks

Mark

[Magic919]

I'd look for someone local with EFiLive or HP Tuners as these will both have the ECU specific codes.

[Storer]

Check that you have blocked off all the un-needed pipes in the inlet manifold. They love to hide them in places you can't see them. If you don't the ECU will take a reading from the air flow sensor that shows much less air entering the manifold than is actually the case. This causes the engine to stall.

May be worth a look.


Paul

[cito quod fortis]

mark999 said:

dont know how to start to scan it for the problem bit of a novice to the building of cars do what i can tomorrow and let you know..

Mark

If you have the GM ECU, I have EFi Live, which can scan for error codes and you're welcome to try it. I'm in Nottingham so not too far from you. Drop me a PM if you need it.

Cheers

Andy