Hot start problem 2

[eatcustard]

Have van serviced
replaced the temperature sender for the injectors
all runs fine.

but will still not start when hot.

what else should I be looking for

[Nicola&Tony]

Starter motor and its connections?

Tony

[eatcustard]

No it spins over fine

Just will not fire up (leave it 15 mins and if fires up)

fuel not getting in, may be?
ignition module?

[kevtherev]

same on both fuels?

[eatcustard]

same on both fuels?

can only start on petrol

[kevtherev]

won't start on LPG at all by design then?

[eatcustard]

By design

[kevtherev]

I believe HOT injection engines need full throttle when you turn the key. if it does, it would suggest there's not an over fuelling problem

possibly temp 2 sensor if that is a problem

[eatcustard]

I believe HOT injection engines need full throttle when you turn the key. if it does, it would suggest there's not an over fuelling problem

possibly temp 2 sensor if that is a problem

new temp 2 sensor has been fitted

foot to floor, still does not help

[kevtherev]

OK
disconnect the fuel pump then start with full throttle to check if it's over fuelling
should be enough pressure in the system to get it to fire up

if this fails we're on to air mass meter or ECU I would guess at

[eatcustard]

Thanks

will give it a go

[kevtherev]

another check
disconnect the temp 2 when it's warm... not hot then try starting, just a check for the sensor, it should be difficult

temp 2 was from Brickwerks was it?

[eatcustard]

temp 2 was from Brickwerks was it?

Yes

[kevtherev]

great
can you get or rather borrow an ECU..? (I wish the club could invest in a borrowable on )

[kevtherev]

just did a search on thesamba..

look up and consider a "hot start Relay" as there is often a Voltage drop from the ageing VW wiring from the battery to the Key switch to the starter solenoid. this relay provides the starter with as close to full voltage as possible.
Also note there is a wire FROM the starter TO the "double Relay" on the firewall, that runs the Fuel pump "while Cranking"

have an assistant check to see (hear) if the fuel pump is running/priming during cranking. it's located under the sliding door by the frame rail, should Bzzzz and such.

if you get it to crank and fire but won't stay running. often there's an issue with the 'fuel pump' switch in the AFM (air flow meter) on the air cleaner housing.
inside there are 2 contacts that touch when the engine is sucking air thru and continues the power to the fuel pump after the Double relay is done with the cranking, kind of a hand off aspect but sometimes needs a little help.

also the cold start valve was discussed.. in being that a leaky valve would cause issue