Garlocker

I've lurked and searched for a while on here now and appreciate all the insight and knowledge you have all put on here and Without it, I wouldn't be this far.

Here's the skinny, I bought a truck broken for what I thought (and still hope) was a decent deal. The previous owner claimed it died on the highway and has been a no-start ever since. When I obtained the truck, it had thevalve covers pulled off and the timing pump pulled off too as apparently it was supposed to be timed...

I put eeverything together, pin timed the pump, and she cranks and cranks. So I've checked the fuel shutoff solenoid of course, changed the overflow valve, replaced the lift pump, and she still cranks
I've tried bleeding by fuel filter, then by overflow valve, then at injectors. I've tried a bypass of the fuel supply lines by supplying fuel directly to the lift pump. And she cranks and cranks.

My only clue is that i think my fuel may be aerated since when i crack the high pressure fuel lines at the injectors, the spray appears to bubble when it lands on the cardboard i lay next to the injectors to capture the spray. My fuel return banjos on the side of injectors #1 and #3 are leaking even after swapping eith new copper seals. So i disconnected the connextion of the injection fuel return line at the top of the fuel filter. But she just cranks and cranks.

So here I am, writing my first post on DTR, stuck on where to go next.

BigIron70

Did you pull the pin on shut down solenoid and allow lever on injection pump to move up to the full run position? Did you pull the access plug on injection pump while engine is at TDC and is the pin centered in the opening?

Garlocker

Hey BigIron,

I haven't tried disconnecting the solenoid from the lever as the solenoid always appeared to engage powerfully. I did try pulling down on the lever against the activated magnet and it didn't budge so I never thought to check the linkages. Its a good thought and I can look into it.

As for the pump, I did recheck the timing tooth and its still roughly centered in then hole. I can still engage the pump timing pin, however it is a tight fit.

gorms

Have you checked fuel pressure? If it's good should just take a good bleeding if the injection pump was off when you got it. Hold the throttle wide open while cranking too.

Garlocker

Gorms,

I did borrow a buddies fuel pressure gauge to check fuel pressure prior to installing the "new" lift pump. I wasn't able to get any fuel pressure readings as the gauge always read 0. I attributed this to the fact that maybe the gauge wouldn't read cranking pressure.

However, the difference between the old lift pump and the new lift pump was very noticeable. As in, prior to exchanging the pumps, I could not get the Overflow Valve to squeak in any way. Now, it takes 2 pumps and that puppy squeaks. So I'm not to suspicious of fuel pressure...but you're right in that I do not have any fuel pressure values confirmed.

What's the best and most fail-safe way to bleed the delivery pump? I've been at it for a bit and do get a good amount of fuel at the injectors. How much air does it take to make a no-start condition?

Thanks for your help on this.

BigIron70

Loosen over flow valve top front of injection pump then pump the fuel primer until you do not see bubbles any more and have fuel coming out. Then loosen fuel lines at injectors half turn crank until you see fuel coming out injector line start tightening lines as you see fuel coming out. At that point should start firing on a few cylinders. May have to give a little throttle if idle
rpm screw is turned down. Good Luck

Garlocker

Thanks BigIron,

I get fuel to the injectors and have tried bleeding the system at the fuel filter, the overflow valve, and the injectors. Fuel sprays up at least 2 feet at the injectors with the fuel lines loosened. So pressure seems good.

Not much as far as combustion, she just cranks. There is a small bit of white smoke coming out of the tail pipe, so some fuel must be getting through into the cylinder...

gorms

How about a shot of (dare I say it) ether or wd40 in the intake horn while cranking? Make sure the grid heaters are disconnected if using ether.

If it won't fire with ether might need to look into the motor a bit...compression, cam shaft, etc.