Injector Lines Won't Prime

Discuss (and cuss) the Nissan LD-series OHC Six diesel engine, popularly available in the US in 1981-83 Datsun/Nissan Maxima Sedans & Wagons.

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83_maxima
Posts: 423
Joined: 13 years ago
Location: Denver

Injector Lines Won't Prime

#1

Post by 83_maxima » 10 years ago

I just replaced the o-ring at the rear of the pump. to do so I needed to remove the injector lines and the delivery valves.

I've got it all back together, and have primed the low pressure side of the pump with my mityvac until NO bubbles came out. I sucked quite a lot of fuel through the pump and expected it to prime the high side rather quickly.

Now, I can't get any fuel to the injector lines. All of the lines are dry. I have drained my battery of most of it's juice so now I'm dead in the water until I can get it on a charger.

Any suggestions as to why the pump isn't priming the lines?

My only thought at this point is to put a low pressure pump on it temporarily to help the vane pump re-prime the high side. Aside from that, I'm out of ideas.

rlaggren
Posts: 541
Joined: 12 years ago
Location: San Francisco

#2

Post by rlaggren » 10 years ago

Assuming the low pressure side is OK (no restrictions or other problems).

Where did you "vac" from?

Did you try "priming" the injectors by loosening the connections at the injector first until you get fuel out?

IAC, remember the starter needs to cool down after 15secs use.


Rufus
82 Maxima wagon

Carimbo
Posts: 459
Joined: 14 years ago

#3

Post by Carimbo » 10 years ago

Looks like you disconnected the injector lines from the IP outlet head? If so, the lines may be not be filled up w/ fuel anymore and this takes a long time to purge. Means a whole lotta cranking. Be kind to the starter. 10-second bursts followed by 1-minute cool-off period. Check the temp of the starter just to be safe. You will need the battery charger; it's easy to drain the battery before you get adequate fuel to the injectors.

Which o-ring did you replace? Was it leaking?

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83_maxima
Posts: 423
Joined: 13 years ago
Location: Denver

#4

Post by 83_maxima » 10 years ago

Thanks for the replies guys.

Carimbo - you were right. Just took a whole lotta crankin'! I did not realize just how *little* fuel is injected via the lines. Took a lot of cranking just to see fuel at the backside of the pump cracking the line or two that is accessible. Finally started to see fuel at the injectors a while after that.

There is a *big* (24mm or so) three-sided "nut" on the back of the pump that seals with an o-ring. That o-ring had started leaking a very small amount months ago, but began hemmoraging about 6 weeks ago. I had to remove all of the lines and delivery valves just to be able to see that I was going to have to grind down a socket just to be able to get it off. But everything is back together and it is running again and not leaking.

Also replaced the IP drive belt, tensioner and fixed some oil leaks, so...progress was made!

rlaggren
Posts: 541
Joined: 12 years ago
Location: San Francisco

#5

Post by rlaggren » 10 years ago

Good to hear. Thanks for posting results

Rufus
82 Maxima wagon

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