DF140 Rough running/Not starting. Help Please!

[Hawaiian GP]

redlowrey, thanks for your input. I have and extra set of ignition coils and swapping them made no difference, I also put inline spark plug pick up tester and it shows they all fire. The fuel pumps are brand new so I assume the pressure will be ok. The temp sensors are also brand new. The map sensor and air temp sensors I changed with used ones and I don't have trouble codes
from the tack for them. I did have a trouble code 1-1 before this problem arrived but no longer have it. I have yet to check that the map sensors work correctly and if i have enough vacuum at the map sensors. Also, I think the engine may be missing on 2 cylinders and not just one as previously stated.
I removed the plugs and the valve cover the other night, all plugs were wet and sooty and the timing chain was lined up at the two front sprockets sort of. They were one tooth past, not as shown on the manual, and I was not able to see the **** chain link location. The chain was tight and the bolts were all in place. Maybe I'll try a bore camera to see the **** link location.
Simon, I have a sds cable and software off of ebay but haven't been able to get it to work. I may just take you up on your offer.
Rich

[redlowrey]

Mate the pumps have nothing to do with regulating the fuel pressure, they only supply it high and low. The pressure reg is inside the vst and it will blow off when the pressure exceeds around 36psi, if for some reason it is stuck you might have sixty or more psi there, simple to check with a gauge fitted to the outlet on the rail. If the temp sensor voltage at the ecu is getting up near 4 volts it will inject way too much fuel, unless you are in the arctic.

On a good engine with good vacuum at idle the map signal sensor voltage will be around 1.5 volts and as you rev the engine will shoot up too around 4 volts, with the key on engine off the map signal voltage will be around 4.5 volts.

Because your engine is running so rich the plugs will soot up quick and the spark can travel up the porcelain instead of jumping to the ground electrode. If you can get hold of a mitiyvac vacuum pump and vacuum gauge try this just so you can get the engine to run a bit leaner, remove the map sensor and make sure the little hole is not blocked.

[redlowrey]

I lost me page, as I said make sure the hole is not blocked, connect the vacuum pump up to the map sensor get your digital volt meter get a thin needle and slide it down beside the wiring plug signal line wire white, and turn the key on you should see around 4.5 volts. Start pumping your vacuum pump and when the voltage comes down to around 1.3 volts leave it there. block the little hole and start the engine, if it still sounds rich let a little bit of air enter the hole and see if that improves it. This test is only to see if it will run back on four cylinders and there is not a mechanical problem. If you find the fuel pressure is way too high there is no need to do this test.

If your wiring is the same as the earlier df 140 check your 5 volt reference voltages grounds and signals start at your map, you should have five volts on your red supply voltage, 0 volts on your ground black and white, and a varying voltage depending on vacuum on your signal wire white.

[Hawaiian GP]

OK here is the latest. I have checked the fuel pressure and its at 33 lbs. at idle.
The Map sensor measures at 3.83 volts when ignition on engine off. I hooked up a vacuum to the map sensor and engine runs best at 2.2 volts but still runs rough. The engine cuts out if voltage is brought down to 1.5 volts. I am still unable to run this engine without the throttle up. I think its the number one cylinder that is not firing. BTW when I pulled the map sensor there was fuel in there.

[Hawaiian GP]

I got it fixed. Tore the engine apart and found a broken valve spring and a couple of piston rings stuck to the piston. So I took the head to machine shop and they changed all the valve springs and valve seals, machined valve guides, checked the seal on the valves, and shaved the head flat. I changed the piston rings myself and honed the block. Put everything back together and it fired right up and it runs smooth.