EGR and Throttle Body Delete

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

Moderators: plenzen, glenlloyd, goglio704, Nissan_Ranger

Post Reply
nissan_nerd
Posts: 16
Joined: 1 year ago

EGR and Throttle Body Delete

#1

Post by nissan_nerd »

I hope this forum is still active after all these years. I recently got my hands on a 1982 Maxima Diesel as a California smog exempt project I can throw any motor into. However, my LD28 is still going strong and I plan to keep it in the car as long as possible. I would hate to see a perfectly good LD go to waste for a 3.1 hack job.

Popped the intake off to clean the NASTY black soot build up after 40 years of exhaust gases from the EGR mixing with oil vapors. To avoid having to go through cleaning it again (DIRTY MESSY JOB!) I deleted the EGR by making a custom block off plate for the intake manifold and shoving two quarters into the exhaust manifold hole with the old pipe fitting screwed in (works very well).

From what I can tell throttle body mounted on the air filter box is part of EGR system. Will there be any issues disabling it? Thanks in advance!
1982 Maxima Diesel
1984 Maxima Gasser
User avatar
asavage
Site Admin
Posts: 5431
Joined: 18 years ago
Location: Oak Harbor, Wash.
Contact:

Re: EGR and Throttle Body Delete

#2

Post by asavage »

Fortunately, the LD28 intake is two-piece and easily cleaned, unlike my '99 MB E300 with OM606, or the Sentra diesel, or the Rabbit, or . . .

The vacuum-operated valve at the air cleaner box operates at idle to make the engine intake noise quieter, and at certain higher RPMs to get enough EGR flow. You can remove and plug the vacuum line to the diaphragm on that flap valve, and it'll stay open always. No need to get more elaborate than that.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
nissan_nerd
Posts: 16
Joined: 1 year ago

Re: EGR and Throttle Body Delete

#3

Post by nissan_nerd »

asavage wrote: 1 year ago Fortunately, the LD28 intake is two-piece and easily cleaned, unlike my '99 MB E300 with OM606, or the Sentra diesel, or the Rabbit, or . . .

The vacuum-operated valve at the air cleaner box operates at idle to make the engine intake noise quieter, and at certain higher RPMs to get enough EGR flow. You can remove and plug the vacuum line to the diaphragm on that flap valve, and it'll stay open always. No need to get more elaborate than that.
I deleted all the vacuum lines and the flap valve. Cleaned out all the grunge out of the intake (Not Fun), and put in a catch can. No longer have any issues accelerating from a stop, and black smoke is now at a minimum
1982 Maxima Diesel
1984 Maxima Gasser
Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests