3.9 Hotwire Won't Run (flooding) - Please Help!

Steve R · Post by **Steve R** » Mon Oct 05, 2009 11:42 am

Hi all,

Hopefully some of you clever people can help me out with getting my 3.9 to run properly...

Problem:
Engine will fire up and run for 10-15 seconds then flood and die. Cannot catch it on the throttle, all plugs then soaking wet with fuel.

It will then only splutter and f*rt a bit and refuses to re-start.

My Setup:
Standard 3.9 (re-built, standard cam & timing gear)
Hotwire EFi (with green non-cat tune resistor fitted)
BPR6E plugs with Bosch suppressed leads (ran ok on previous 3.5 flapper engine)
TVR 4.3 ecu chip (not my choice but was fitted to ECU)
Ignition module upgrade (from this forum) & new Bosch blue coil
Standard 3.9 fuel pressure regulator & green injectors

I initially had problems getting a spark but this now appears to be fixed with a new ignition amplifier and coil.

I have checked the fuel temp sensor and the resistance appears to be OK when compared to the values in Mr Haynes.

There are no obvious air leaks.

The cold start stepper motor thing seems to be working (can hear it moving).

I have read this thread with interest

http://www.v8forum.co.uk/forum/viewtopi ... t=flooding

and it would suggest that I need to get some new plugs.

Do you think this would be a good next step? If so, should I go for non-resistor plugs rather than BPR6E plugs, or would I be better replacing the fuel pressure regulator first?

Unfortunately I don't have lots of spare EFi bits lying around to be able to substitute parts.

Any help would be very much appreciated!

Cheers,
Steve.

Ian Anderson · Post by **Ian Anderson** » Mon Oct 05, 2009 12:24 pm

Overfueling can be because it has tripped over and gone into limp home mode - incredably rich but will not break anything!

Disconnect battery for 30 secs as a minimum
Reconnect and start immediately - should have reset the ECU

If not then it's test and test again per Mr Haynes - I had dripping plugs and left them in and they work fine perhaps I was ucky as I have heard once wet a RV8 don't like the plugs

Cheers
Ian

Steve R · Post by **Steve R** » Mon Oct 05, 2009 1:16 pm

Thanks Ian,

Forgot to add that my battery has an isolator switch fitted so the ECU is usually powered right down. Hopefully this will have cleared any previous fault codes.

Looks like I will just have to work through all the electrical tests in the Haynes manual to narrow things down before resorting to buying lots of expensive new bits.

Cheers,
Steve.

r2d2hp · Post by **r2d2hp** » Mon Oct 05, 2009 3:49 pm

When I was using the 14CUX setup I bought the 2 digit display that can be connected to the the wiring harnes using a 4 pin plug (not all have the plug). It shows an error code that identifies the faulty component. It was not cheap but saved me money in the long run.

Think I still have it somewhere

Ian Anderson · Post by **Ian Anderson** » Mon Oct 05, 2009 4:00 pm

Check the earth connections

Check that the return pipe is not blocked - if it is there will be massive fuel pressure

Ian

Steve R · Post by **Steve R** » Mon Oct 05, 2009 5:28 pm

Thanks,

I will have a look for that diagnostics connector later. Found this unit on the web for around £100 which may be money well spent:

http://www.bespokeintelligentsystems.co.uk/Products.htm

I'll also check the earths (ones on back of cylinder head?) and return line for fuel.

Cheers for your suggestions.

Steve.

r2d2hp · Post by **r2d2hp** » Mon Oct 05, 2009 6:02 pm

If your ing of getting one of them let me know. I have a genuine Land Rover item that I would be happy to sell for less than that item.

The codes have the same meanings

Steve R · Post by **Steve R** » Mon Oct 05, 2009 6:24 pm

Cheers - will definitely bear that in mind if my loom has the right connector for it...

Eliot · Post by **Eliot** » Mon Oct 05, 2009 7:17 pm

Have you got the vacuum pipe going to the fuel pressure regulator?
At Idle there is a high vacuum, which reduces your fuel pressure - leaky/missing vac pipe or FPR will result in fuel pressure thats too high for idle - possibly causing over richness?

Steve R · Post by **Steve R** » Mon Oct 05, 2009 8:30 pm

Ok, just had a quick look at the old Lightweight to eliminate a few things:

1. Fuel return line
- Looks ok, plenty of fuel returning to tank.

2. Vac pipe between plenum and fuel regulator
- Is definitely attached but too dark to check for splits etc. I seem to recall there was no obvious damage when I re-fitted it recently. Do the internals of the regulators perish with time and is it possible to test them in any way?

3. Diagnostic plug is present in my loom - r2d2hp I'll send you a message as I'm keen to do a deal!

I managed to get it running for a bit longer tonight - definitely firing on all 8 cylinders for a minute or so. Shut it down, checked plugs and looked ok (no fouling or wetness). Went to re-start it but wouldn't fire up - just stinks of petrol and wet plugs again.

Hmm...

Robrover · Post by **Robrover** » Tue Oct 06, 2009 7:15 am

Have you checked your fuel pressure at the rail? If it's too high it'll lift the pintle off the injectors and flood. Have you tried another ECU with a standard 3.9 fuel map to see how it compares?

Steve R · Post by **Steve R** » Tue Oct 06, 2009 4:55 pm

Haven't got a fuel pressure gauge unfortunately so don't know if the pressure is too high at the rail.

I agree that the pressure regulator may be causing this, but I'll probably work through all the electrical tests in the Haynes first (and maybe use a diagnostic plug-in box) before buying a new regulator.

I have just re-checked in daylight and the vac pipe is definitely attached to the pressure regulator and in good condition.

Good point re swapping ECUs - will see if I can borrow a standard one from a mate. (I've no idea what the TVR chip is in mine).

Cheers,
Steve.