Resealed IP on AHU and now won't start

Hi, i removed my IP and took it apart to replace all the seals and o-rings, I think i put it back together properly but now once back on the vehicule the engine turns over for at least 10 secondes then it fires for a breaf momment ( half a second ) then it dies.

I don't have any fault codes
I have 12v on the shutoff solenoid

Question 1
How much fuel is returned to the tank from the IP, i disconected the return line from filter and sent to bottle, after cranking 10 sec. i didn't have much fuel in there ( should i see a flow comming out or just a drible )

Question 2
I put a clear line from a container of fuel siting on the engine and when cranking the pump pulled fuel up the container and into IP, does this mean my IP is pulling enough fuel to feed the high preasure portion of the pump.

Thanks for any guidance on what to do next.
Paul

well, as long as you didn't really screw anything up. it's common to have to crack an injector nut at a time before the engine really fires up and stays going

If you don't prime (pull fuel) through the IP with a mitivac or electric pump it takes a long time to fill.

Pump was primed with mityvac.

Tried the loosening of the injector nuts,,,not just cracked but unscrewed a full turn, there was hardly any fuel seeping out while cranking and just a bit more when it fired for half a second.

Shouldn't it have made a mess of fuel with the nut unscrewed a full turn ??

IN EVERY CASE THE ENGINE CRANKS FOR 10 SECONDS, FIRES FOR ABOUT HALF A SECOND AND DIES

Can anybody give me advice on my 2 questions, i'm thinking i messed up the front fuel fed portion of the IP, i read that some people had to put an electric pump before the IP

Paul

Check for voltageat the fuel cut off solenoid. It could be failing, have no power, our be installed wrong.

did you match mark the middle case to the body. it it is off (the part you hammer mod) then you wont get fuel. too far other direction it will rev out of control.

Have you checked the timing?

Tony
Sent from my e-diesel fleet

I have steady 12v to solenoid
I made a scrib mark and aligned the top portion ( the portion that is hammer moded )
I verified timimg twice

Paul

You verified timing twice...was that mechanical? If so, that's only half the battle: that was static timing.

Try advancing the pump, I.e. rotating the pump towards the engine block until it fires. Then you can set dynamic timing with vcds.

Tony
Sent from my e-diesel fleet

Paulsta said:

Shouldn't it have made a mess of fuel with the nut unscrewed a full turn ??

Click to expand...

Not really. You usually need to bleed at least 2 or 3 of the lines. It should start, but will stumble before smoothing out.

Are you getting smoke at the tailpipe? If so, that's a good sign. On my B4, I had the static timing correct, but was only getting smoke, when installing a rebuilt pump.

I had centered the IP, but wasn't able to get the engine started, no matter which way I was moving the IP. I ended up advancing the pump by a tooth and the car started.

-Todd

I probably worked 5 or 6 hours trying to start the engine, had to recharge the batterie a few times, but eventualy it fired, but it still takes 10 seconds of crancking before it fires, hopefuly i can play with the timing of the pump to solve that probleme.

Thanks for all the input.

Paul

If it is running now - you can plug in a VagCom cable and check/set the injection pump timing.

If you don't have access to that , you can set it mechanically with a dial indicator gauge.

Best thing to do when winging it , is loosen the 2 nuts for the injection pump adjustment that have to be accessed through the inj pump sprocket.
Then have the other 2 that you can access externally - loosely snugged.

After engine running - un-snug the 2 external bolts and slowly move inj pump toward engine - or away from engine - whichever makes improvements. Find a nice happy medium and tighten the bolts.
Then re-tighten the nuts inside the sprocket.

After you exhaust the best timing setting you can - if it still has issues - then go into the IQ adjustment - with engine running.