Full Load Adjustment

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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LD'd VC
Posts: 8
Joined: 12 years ago
Location: Christchurch, New Zealand

Full Load Adjustment

#1

Post by LD'd VC »

I have recently dropped a replacement LD28 into my car, (the old ones compression crapped out). I've been driving it for a month now with no problems, the only thing I'm finding is when i try get over 100 kph it feels like the control sleeve in the injector pump is spilling fuel. Revs are sounding good, cant get a reading coz my commy has still got the old manifold vacum gauge. All I need is that little extra to overtake. Am i right in thinking that the Full Load needs tweeking I havn't had to fiddle with an injector pump yet so just checking before I start.
LD'd VC
Posts: 8
Joined: 12 years ago
Location: Christchurch, New Zealand

#2

Post by LD'd VC »

Ha sorry for the four of the same messages, I've got more troubles with my computer than my car.
Carimbo
Posts: 467
Joined: 18 years ago

#3

Post by Carimbo »

Clogged fuel filter can cause that symptom. Try changing the fuel filter first.
LD'd VC
Posts: 8
Joined: 12 years ago
Location: Christchurch, New Zealand

Tried the fuel filter

#4

Post by LD'd VC »

Thank you for the advise to change the filter.
I changed the fuel filter in the weekend. On inspection the filter looked fine I changed it anyways. I went for a drive to see if anything has changed, but still you can feel the pump limit out in each gear. In fifth it was limiting out 105 kph and I still had plenty of throttle to go. Is it because this motor ran an automatic and the fuel pump is set to limit out at lower revs than a manual?
rlaggren
Posts: 541
Joined: 17 years ago
Location: San Francisco

#5

Post by rlaggren »

The FSM gives the max revs set from the factory. Don't recall what it's supposed to be but you can find it here somewhere along with options for a tach. May not be a great idea to go over that limit - as in might break something. With the auto tranny in the Maxima the car will run up to 55 or so mph in 2nd gear before hitting the rev limiter. Don't know if your speedo will read the same off the LD tranny - would depend on what gearing your speedo was expecting from the drive cable.

If:
- you're sure you don't have a fuel blockage (see this topic, 2nd post) nissandiesel.dyndns.org/viewtopic.php?t=2016

- your intake manifold is clean of obstructing grunge (search "grunge" this site)

- your intake path is large and clear

- the exhaust is 1-1/2" or so and clear of obstruction...

Then you might try tweaking the smoke screw a small bit "richer". IIRC you get a _little_ smoke on WOT when the engine's doing it's best.

Also, Al, our host, has theorized that worn pump vanes on the lift pump in the back of the IP would lower housing pressure and affect the advance mechanism. Which could lead to reduced power at higher revs.

FWIW.

Rufus
82 Maxima wagon
LD'd VC
Posts: 8
Joined: 12 years ago
Location: Christchurch, New Zealand

#6

Post by LD'd VC »

Cheers
LD'd VC
Posts: 8
Joined: 12 years ago
Location: Christchurch, New Zealand

#7

Post by LD'd VC »

Ah thankyou for sheding some light , the link brings up a good point, I'll check out the tank and fuel line in the weekend.
JasperG
Posts: 95
Joined: 14 years ago
Location: Bradenton, FL

#8

Post by JasperG »

tweeking my smoke screw helped a tad with my 2.8, but I had a smoke issues (white lean smoke).Dont turn it much at all, maybe a 1/4 turn at a time. Gordo
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