BF130 Strange Issues Starting/Running

Hi All,
I've been doing a lot of reading on the forum, but unfortunately have got stuck with a starting/running issue on our BF130.

I bought the engine as a non-runner with the vapour separator removed, I trust the seller who said it ran well before the high pressure fuel pump casing broke. That's now sorted but I can't get it to run properly.

My compressions are relatively even around 150psi (throttle open, all plugs pulled). I know that's a bit low, but it has been sitting 6 years, and I'm doing the test cold. I don't have the kit to do a leak-down test.

I've checked the timing marks, belts and tensioners are fine, valve clearances are ok. I'm getting spark to all cylinders, plugs also tested and swapped out. batteries are new and charged, it spins over no problem.

When I try to start her she will kick for half a second and die. BUT with any of the 4 plugs pulled (not lead, actual plug removed) it will start immediately and run on 3cyl no problem indefinitely. I've not rev'd it above idle running on 3cyl.

As soon as you put the 4th plug back in it stalls immediately. Even holding your hand over the plug-well will stall the engine.

I'm pretty competent mechanically, but this one has me stumped!

Any guidance gratefully received.

Thanks,
Duncan

Try increasing the rpm a bit while running on 3 cylinders and install the plug?

I’m not talented on all the sensors here but I’m stumped like you. Fuel starvation and it’s not getting enough fuel to run 4 cylinders?

The only thing that can affect is the MAP sensor, try checking for fault codes by bridging the two pin diagnostic plug.

Many thanks for the replies and pointers.

I'm pretty sure its not fuel starvation, when I've got a plug removed that injector would still be firing.

That's a good shout pulling codes, I'd not actually considered doing that.

I'll have a go over the weekend.

Well after a bit of tinkering I got her to fire up, compressions seems to have improved and I think I'm good. Many thanks for the help.

What did you figure out?

NSDON said:

What did you figure out?

Click to expand...

Truthfully I think it was mostly new owner error! I didn't realise it needed a fair bit of throttle to start from cold. Coupled with that I think not having run for 6 years wasn't helping the compression. I'm not 100%happy with the compression figures, but its healthy enough to give it a good blast at WOT and see if I can burn off some carbon.

Run some sea foam through it, be generous with the amount, it will clean out the fuel system and valves. Be happy it was this easy.

And from here on, add Yamalube Ring Free at 1 oz per 10 gallons about every other fill up. Over time that will burn out the carbon and keep everything nice and clean inside.