Think Tank Run Dry on Non Starting 3.9 RRC

My gut feeling is still to do with how it cut out, Rumble strips etc................something has moved or fell off after the vibrations..............i know that's easy said and not so easy to find, Keep the faith Saint...............keep the faith

Hi Anthony,
Just to recap as I have lost the thread so to speak.

1 Will not start on petrol.
2 You have a good spark
3 You have petrol at plugs
4 Turns over at a good speed
5 All ignition parts are genuine Lucas or Bosch
6 Timing has not been touched
7 You have good pressure on the fuel line

Are these all correct?

Fred

Hi Fred,

1 Will not start on petrol. CORRECT
2 You have a good spark CORRECT-ISH (see below)
3 You have petrol at plugs INCORRECT
4 Turns over at a good speed CORRECT
5 All ignition parts are genuine Lucas or Bosch CORRECT
6 Timing has not been touched CORRECT-ISH (see below)
7 You have good pressure on the fuel line CORRECT

Do not have petrol at plugs....turn her over for about 30secs then whip out the plugs smartish...and they are bone dry....they don't even smell of petrol....I don't think the injectors are opening.....

I have checked for a positive feed to the injectors (brown and something wire) and I have 12volts there......(the ECU switches the injector ground to pulse the injectors) so it would appear that the injectors aren't getting a signal to open from the ECU....

This could be caused by....

The ECU doesn't know the engine is running...(Signal from White/Black wire from Coil -ve) this could be because the Signal isn't getting though...(checked wire and all is well) or the signal is weak - possible amp fault but it does switch the coil as I get a spark..!!!

OR

The LPG System is blocking the injector pulse via the two relays on the bulkhead....although these have been changed for new...!!! AND I have checked the resistance from ECU plug to injectors and the reading is as per the book i.e. the signal is getting through to the injector coils...!!

OR

Wiring fault between ECU and Injectors.....again as above, the reading indicates the wiring is all present and correct...!!!

OR

The ECU thinks it's a toaster....!!!!

When I changed the rotor arm, I fell foul of the usual problem of 'Stuck Rotor on Shaft' syndrome.....before removing dizzy, turned crank so at TDC and rotor pointing to No.1....removed Dizzy, cleaned, replaced weights and springs, reset airgap, and replaced Dizzy.....retimed using strobe, allbeit with the engine turning over on the starter to roughly the right place around 6 BTDC....enough to atleast get her started.

Coil, leads, plugs, cap and arm replaced....spark still a bit weak...but should be more than enough to atleast cough or splutter....especially when the RAC man used EasyStart....nothing.

Fuel pressure checked at the rail using a pressure gauge from fuel feed line to rail...holding nicely at 38-40psi.

Everything I have checked indicates that she should start...except for the fact there is no fuel getting in....and everything checks out that there should be no reason why fuel isn't getting in....

What to do....what to do.....I am stuck.

I have a suspicion it is the ECU....but I don't want to spend out on an ECU....plug it in and still nothing...money wasted.

I am trying to eliminate everything before I go down that route....if you know of anyone with an ECU we could try I would be grateful to be able to give it ago....at least then I can maybe concentrate on everything else, safe in the knowledge the 'brain' is still thinking it is a Lucas 14CUX and not a rather expensive paper weight...!!!

Any Ideas..???

Rgds,
Anthony.

Hi Anthony,
Sounds like fuel starvation.
When I had a similar problem it was due to a faulty fuel pump playing up, worked on somedays and not on others. A friend had a blockage in the fuel filter caused by muck being pushed up as pressure built up causing fuel starvation. But you have checked fuel pressure so it can't be that, the next fuel problem I had was the coolant sensor, cheap to replace and will stop the engine dead if it fails open circuit.

You probably have done the following but I am only trying to help........
Are you certain you have not replaced the dizzy back 180 deg out?
Have you checked no.1 is correct?
Are the bob weights and springs working? you should be able to rotate the rotor and feel it spring back.
Have you replaced the leads correctly, and pushed them home fully in the dizzy cap, particularly the right angle ones ?
Have re-crimped the connection on the ignition coil?
Have you disconnected the capacitor from the ignition coil?
Have you connected a thick earth lead from negative to engine block in case earth strap is failing? Mine fell off..
Is it a flapper MAFF and if so has it stuck?


If you have then can you substitute the ECU with a good one?

You have a real tuffy, good luck
Fred

Many Thanks Red...

Have tried all of those....see earlier posts....the coolant sensor was the first thing to change....

As per earlier posts...all connections to coil have been remade....there was never a capacitor fitted to the coil....engine earth is good....dizzy has been rebuilt and spings back fine....leads in correct order..checked and double checked then checked again....

At a lose now....need to find helpful person with ECU/ECM to try out ...as I am running out of things to check.

Thanks for your post...keep thinking....let me know if you have thought of anything else I could try....

Rgds,
Anthony.

ECU

I have a 3.5 but I know there a few different ones and you have a 3.9 so they are probably not the same.

But start a new thread requesting help from someone with a 3.9 and you may be surprised how helpful other members are.
Worth a try

Fred

Hi Fred,

As you say, the 3.5 and the 3.9 use different ECU, thanks for the thought though....

Rgds,

Anthony.

If I wasn't 250 miles away I'd volunteer a hand...

Hi Take5,

Many Thanks, but, yes, 250 miles is a bit much....

Very kind of you though,

Rgds,

A.

Just a quickie....(oh, er , misses..)

What would happen if I earthed the pins for the injectors?????

Anyone tried this?

Rgds,
Anthony.

Quick Update:

Earthed the injector pins....did this by finding and old momentary push button switch, old pair of multimeter test cables and a length of wire with crocodile clip attached.

Poked the test probes into the back of the ECU connector (pins 11 and 13) and connected the crocodile clip to earth....

Switched ignition on then pressed the button briefly a couple of times, just to squirt a little in, then turned her over.....nothing....hmmmm

Turned her over while pushing the button on and off (in a vain attempt to simulate injection pulses!)...still nothing....definate smell of petrol though.

Whipped out a plug....loads of petrol....still didn't start though.

Thought I would check for a spark (even though I had done that previously)....nothing, no spark at all.....

Removed the ignition amps (I have two fitted) took them to the local motor spares shop and he tested them both.....both faulty.

have ordered new ones, and will see what happens later today....

Should've ordered the AR Poweramps as they give 50kVA spark fer £120

Wot - every spark - thas a bit expensive, even fur a Rangie - int it?

Aye well, if yer want the best

You little toad, I tried to point you to dizzy problem.
Don't forget the reluctor coil is a classic to fail.
While you have the dizzy out check it for continuity they fail o/c, but check again as the leads go into the coil as the input leads can break where they flex on the advance retard plate.
Amplifier cost me I think about £24 and came with the silcone grease and the new type connector.
Sadly my reluctor coil went when I bumped down a kerb, it cost £95.

Glad to hear you are getting soewhere.

Fred

I finally have proof....THERE IS LIFE AFTER DEATH....

Fitted new Amps.....nothing....swore like a Docker....

Went over everything.....still nothing.......run new positive feed to coil........nothing......removed, cleaned and gapped all the plugs..(again).....still nothing.....

Decided bugger it......removed all the LT wiring to the coil and Amps.......

Remade all the wiring.......until I got to the second Amp on the wing next to coil..(I assume something to do with the gas system..)...something didn't look right....it seemed that the input wiring to the mutliplug on top was the wrong way round......NOTE: I did not touch any of the wiring to or from this Amp previously.....couldn't figure out why it was the wrong way round or the purpose of it.....so I disconnected the power to the Gas system and disconnected this amp from the LT wiring.......

Held breathe and turned the key.....................................

SHE'S ALIVE.....SHE'S ALIVE.............

Running well(ish) retimed using strobe until she ran ok and adjusted the idle speed screw a tiny bit........brilliant.

Now all I need to do is rewire the Gas system.....Please see my new thread......SHE STARTS....BUT HOW THE F*** DO I WIRE THE LPG SYSTEM?

A great many thanks for all your assistance and comments, I would never have been able to solve this without your incredible guidance and friendly approach.........THANK YOU.

Rgds,
Anthony.

P.S. Don't forget to visit the new thread for more fun and games...!

Tervueren said:

Thats what I get for not reading the whole thread
Still bet it's lpg related though, is there a way of disabling the lpg system ?

Click to expand...

I know....I know....

Queue the 'I was right...' song for Tervueren

Don't suppose you know how to wire up this second Ig. Amp do you...??

Well Done on a diagnosis well spotted........

Rgds,
A.

Lovato Gas

The site is being rebuilt but you can e-mail them for advice [email protected]

Once again....well done....you are a Super Star....

I will drop them a quick buzz and see what turns up...

Thank you....