P38A 4.6 cranks, sparks and coughs but won't run - Fuel pressure?

Hi,
I am a newby to Range Rovers and have taken on a project to build a light weight tube frame rear engine buggy using P38 mechanicals.
Been helping a mate race a RR classic based Bowler and quite liked the rear engine buggies racing in the comp safari's.
Donor car is a 1995 P38A with Gemms that was refitted with a Coscast engine about 60K Miles ago. Assured it is a good engine but need to see it running and check it does not loose coolant before I tear it down and simplify electronics (to engine + trans management only). It has not been running for about 4 years. Brother has 99 p38b with Bosch management (and in need of top hatting) and managed to get key code entered and alarm off with EKA technique.
Engine winds and coughs (has spark) and almost catches but won't run. Suspect fuel pump is not running while cranking.
The fuel pump does it's 3 sec approx bit (Fuel flows at entry to injection rail) when key is turn to position II and then stops as I have seen is normal. I expect it then continues to pressurise the rail when cranking but suspect it is not doing this. Checked relay, fuse and inertial switch - all appear ok. Could it be crank position sensor or check valve or pressure regulator. I will buy a fuel pressure gauge. Not sure if my OBDII analyser I use for the corvette (C6) will work on the LR.
I have downloaded the P38 RAVE manual and electrical trouble shooting guide in pdf but it is difficult to navigate (just one big document). It assumes more accurate location of the fault as a starting point which is difficult without fault codes. It does have an injection fault warning on the dash panel when cranking. Check engine light does come on so not likely to be synchronization fault which appears to be common. Unlikely it would fire at all if that were the case.
I have looked on this and other forums but not seen (or been able to find) anything similar.
Any help appreciated.

Bob Tail (Aberbeenshire)

a standard code reader will give the generic codes but if you want deeper access you'll need something specific for the P38

How old is the petrol? I have a 38 that had been standing for 5 yrs and the petrol was stale and it also fecked the pump. New pump and petrol sorted mine.

Hi Alan,
Put new fuel in the tank and pump is working on position II and sends a good burst of fuel through for about 3 seconds. So the pump is working.
I think the problem is that this initial pressure is either not being maintained or the pump is not running while cranking to maintain pressure. It does not run so I don't know if the pump will continue to run after the engine fires. My next best guess is to hot wire the pump (by cutting a hole in the floor under the rear seat) but maybe there is an easier way (from the relay terminals?). I was hoping someone else would have seen the same problem and known how to fix it.

All want to do is see it run before I tear it down so I can tell if the block is water and pressure tight.

I am really looking forward to cutting all the loom out and just running an engine and trans management system.

From what I have read it is likely to be a fault in the fuse relay box behind the battery but it could be pump, check valve, regulator or crank sensor. I was hoping someone could help track it down. My GM Scantool reader will not read the rr codes.I thought the C6 Corvette was bad but the P38 is in another league with electrical gremlins.
This link takes you to a truly incredible fuse box repair http://www.rangerovers.net/repairdetails/electrical/fusebox.html

Any and all suggestions most appreciated. I am continually amazed at the inventive solutions people have come up with to fix this truly horrible monster (electrically).
How can you still love it!
My daily drive is a defender 90 300tdi and I put fuel in it and turn the key - that's it and that is how it should be - has any one hatched a plan a plan to extract revenge on the twisted soul who invented this management system????

Bob

Crank sensor. Those feckers always catch you out.

You can bridge the terminals of the fuel pump relay to run the lift pump.

Need Nanocom or similar o read engine codes etc. Once you have the right tool it is easy, or easier. Have a look at the Landyzone International Resue Map and see if anyone is close with diagnostics.

I have nanocom for GEMS and will be in Aberdeenshire Mon and Tues if you want it

I would have thought crank sensor too, I would also have thought there would be enough pressure if the pump is priming, for one burst of starting before dying off so perhaps the sparks are weak.

Once had a car that wouldn't fire up and yet everything was perfect. So I unbolted the cat, turned her over and she burst into life!! Cat had collapsed, blocking the exhaust. It was an MGF. Once we replaced the cat, exhaust system, O2 sensors, plugs and so on, it was a beast that would take off sideways, much to the delight of it's owner

So, farraboot in Ehberdeeen shire are ye, ken?

oakey said:

I have nanocom for GEMS and will be in Aberdeenshire Mon and Tues if you want it

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Oakley,
That would be great. I am out by Inverurie. Send me an PM. I plan to be working on it Monday evening but will also be at the workshop or nearby Monday afternoon. I will also see if I can lay my hands on a fuel pressure gauge.

Any details on shorting the pins on the relay to make the pump run continuous during cranking. I am pretty sure it is starving for fuel so maybe something is not telling the pump to switch back on after the initial 3 sec prime.
Will try find a spare crank position sensor. Planning on pulling an injector and check for gumming from old fuel also.

I would work on it tomorrow but away at BORDC (Castle Craig Lumsden) trials with the 90 - doing what it does best - playing in the mud with winches and diff locks!

Bob aka Al

Bob tail P38 said:

Oakley,
That would be great. I am out by Inverurie. Send me a PM. I plan to be working on it Monday evening but will also be at the workshop or nearby Monday afternoon. I will also see if I can lay my hands on a fuel pressure gauge.

Any details on shorting the pins on the relay to make the pump run continuous during cranking. I am pretty sure it is starving for fuel so maybe something is not telling the pump to switch back on after the initial 3 sec prime.
Will try find a spare crank position sensor. Planning on pulling an injector and check for gumming from old fuel also.

I would work on it tomorrow but away at BORDC (Castle Craig Lumsden) trials with the 90 - doing what it does best - playing in the mud with winches and diff locks!

Bob aka Al

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I think I can work out the relay pins ok, 1 will be power, 1 earth and the one that goes live for 3 sec on position II on key will be signal so the other must be the feed to the pump. Just tried pulling the emergency tow fuse we had in slot 11 (put 30 amp from slot 8 into slot 11 to make transfer case shift to neutral for towing but forgot to put it back). Made no difference. Trials were good except for a slight disagreement with the clerk of the course over my position relative to some crossed canes. Its a ****er when the bureaucrats get in the way of having fun. Whats an inch either way when you are taking a shunt anyway! Truck went faultlessly.

I'd not post my e-mail address unless you like spam. Use private message.

Grrrrrr said:

I'd not post my e-mail address unless you like spam. Use private message.

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Private message function on this forum appears to be well hidden - any leads?

Bob

Bob tail P38 said:

Private message function on this forum appears to be well hidden - any leads?

Bob

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It runs, sweet as a nut. Hot wired the fuel pump and ran a gallon of fresh fuel through, good fuel pressure when cranking but no check valve. Pressure drops off immediately. Changed 3 plugs out for fresh ones (hard to reach the rest and feeling lazy). Fired it up and it cleared all 8 plugs and runs like a top.
Seems like I have found a good motor.

Many thanks for all your help. Would still like to meet Oakley and try out his code reader if you are reading this?

Will post some pics later.

Bob

Hi Bob Sorry nut I left for Aberdeen on Sunday and had no net when away o missed your post on Monday
Sorry left again now

Hi Oakley, still getting used to this forum. It has some strange quirks. Seems you have to press the post reply button twice. First time is kind of view draft function I was not expecting (might just be my laptop or big fingers!). Maybe next time you are up. Starting seems to be intermittent now so will get a crank position sensor and check that as well. When it goes it runs well (no fault codes or faults pending) but again sometimes just coughs and revs once then dies (sometimes multiple rev/die cycles). plenty fuel and good pressure so must be spark or signals cutting out intermittently. Ran her for 30 mins yesterday and no gas bubbles in header tank so looks like a good motor. Attached is a picture of what I want to build from her but maybe a bit sleeker looking - more like my VW powered rail. Will be hard to reconcile carting the big heavy live axles around. I may ditch these for a renault trans axle (mid engine congiguration like a GT40) and desert race style trailing arm suspension, long A arms up front, and maybe hydraulic drive front hubs (won't need much from the P38 if that is the case so lots of parts available). We will see how it goes. It might be an evolution away from the landrover drive train.
Next time you are up this way give me a bell or email.

Bob aka Al

I will do ta
Good luck with machine