Another newbie with a V8 Trike thats driving me nuts !!!!!

Overdog · Post by **Overdog** » Sat May 04, 2013 4:30 pm

Hi everyone I am new to this forum and its like a last chance for me and this trike. I have tried everything I can think of and asked questions on many a v8 site but can find no answer to this old girls problems. Im afraid Its going to have to go for scrap soon

Ok the engine is a stage 2 v8 3.5 built with a new block running reconditioned twin SU hif44's. Lucas d35 dizzy body with Lumenition optronic ignition system passing thru Lumenition coil and Ballast resistor. Fuel pump is a solidstate 5lb/sqinch running thru a pressure reducer to 3.5lbs. the gearbox is a BW65 3 speed auto and the rear axle is full width xj6.

Now for the problems. It refuses to run at all if the static timing is set below 14 btdc. I can set the carbs up at tickover using a flow meter and a colour tune and get them really purring. however as soon as you drive it, it runs like a bag of nails ie no power at all popping back and seems to lose 4 out of the 8 cylinders.

timing marks have been verified as true using a dial gauge to find tdc
vacuum advance and bob wieghts are working. the most advance i can get at 3000rpm is about 24 and thats starting at 14 static.

anyone got any ideas before I scrap it.

edit. sorry i cant seem to post a pic of it

JSF55 · Post by **JSF55** » Sat May 04, 2013 8:40 pm

You dont need the / in the first [/img] ... just [img] do all 8 plugs fire ? how about cam timing ?

Post by **scudderfish** » Sat May 04, 2013 9:07 pm

Overdog · Post by **Overdog** » Sat May 04, 2013 10:20 pm

JSF55 wrote:do all 8 plugs fire ? how about cam timing ?

yes all 8 fire and the cam hasnt been altered since realsteel built it. great compression on all 8 ( so it should, the engine has only done 3k miles) no air leaks etc etc . it was running like a dream until this year. nothing has changed except for the oil and filter and new super unleaded fuel. I have handfuls of hair here..and I cant afford to lose anymore :}

Overdog · Post by **Overdog** » Sat May 04, 2013 10:21 pm

Thanks scudderfish :}

Darkspeed · Post by **Darkspeed** » Sun May 05, 2013 7:13 pm

Main jet blocked in one of the carbs
Incorrect float heights
Stuck needle valve
debris in the fuel supply line to one of the carbs
Low fuel pressure

It sounds like a weak mixture - a weak mixture needs more advance and if it does not get it will spit back. As each carb feeds 4 cylinders two each side then dropping to four and spitting could be an indication of one carb being a problem.

stevieturbo · Post by **stevieturbo** » Sun May 05, 2013 9:23 pm

As above, sounds like fuel starvation.

Rig up a fuel pressure gauge on the line from regulator to carbs to ensure you have a fuel supply during this problem.

Overdog · Post by **Overdog** » Mon May 06, 2013 6:46 am

Good News !!!!!
I spent another day yesterday checking everything again. Changed the rotor arm, distributor cap, coil, removed the carbs, set float heights, checked the jets and needles, checked fuel supply. rechecked timing marks and reset timing. Fired her up and....just the damn same.

So on a whim I dug out an old set of plug leads and removed the Magnacores. Started it...no difference.

Took all the plugs out and replaced them with another brand new set of NGK BPR6ES....still the same.
Then I found an old set of Bosche plugs that I had in it last year, set the gaps to 30 thou cleaned them and fired her up...ticked over like charm, road tested and whooohooo the old girl has got her mojo back, never missed a beat. so just for giggles I removed the plugs and set the NGKs to 30 thou and tried it again...back to being a bag of nails
So I guess she just doesnt like NGK,s How strange is that

Thanks to everyone who offered advice.

DaveEFI · Post by **DaveEFI** » Mon May 06, 2013 8:14 am

What is the engine from? Early ones use short reach plugs - NGK BP5HS, later ones BP5E. EFI engines use the BP6RE

Overdog · Post by **Overdog** » Mon May 06, 2013 8:26 am

DaveEFI wrote:What is the engine from? Early ones use short reach plugs - NGK BP5HS, later ones BP5E. EFI engines use the BP6RE

All I know is that its a stage 2 engine built by RealSteel. It was originally in a landrover offroad racer which the guy that owned it managed to total it so I bought the engine from him and replaced my old SDI in the trike. Its always had long reach plugs in it. Its def not EFI. and the BPR6ES were recommended by Rimmer bros.

Darkspeed · Post by **Darkspeed** » Mon May 06, 2013 12:25 pm

BP "R" plugs are not designed for the Rover ignition system - they are resistor plugs and typically used with cars with very short ignition leads coil packs and lots of on board electronics to be protected - the long lead length of the rover the lower ignition voltages don't like resistor plugs.

You would have found all the long lead plugs would have been packing up.

Use a non resistor type.

V8UK · Post by **V8UK** » Tue Oct 29, 2013 12:49 pm

Glad it's all sorted now chap!

Hopefully you can start to enjoy her again!