Swapping in late model intake manifold to early model

[emac]

Well today I started this job. Let me tell you if you can afford to pay someone to do it for you then do it

Because it better be worth the scrapes and cuts, it comes apart fairly easily till you get to removing the fan/ PS pump mount, on my '94 I have to remove the AC compressor to get to the side bolt, which also means removing the sump guard.

That done all the manifold bolts come ou easy except for the lower rehear two especially the second from the rear as i have extractors and the bolt is 80% behind the extractor pipe

I had to fit a ring spanner on it from above then get under to try and loosen it

Finally got it

Putting the new manifold on I simply couldn't get the back two lower bolts in to had to remove the manifold screw the two bolts in a couple of turns then jiggle the manifold back on

There are two aligning dowels that don't help

I've got it about half way back together and took 6 hours

Probably anothe couple to go

But time for a beer now

Gees this better work

Oh for. The moment I'm staying with the stock injectors and fue l pressure reg.

I also want to check my fuel pressure as I wondering if the existing reg. Is working there was no sign of fuel in the return line, it looked dry as a bone

Ok where's that beer

[junglejuice]

The 94 is OBD1, when mine was OBD1 I did the same swap, I ran the stock injectors and reg but I run extractors and a 2.5"/2.25" exhaust, I also ran a Throttle Body Spacer (TBS).
Mine had a horrid tendancy to ping under load especially on warm days on regular unleaded, on premium I found a noticable increase in performance AND fuel economy and eliminated my pinging, all that was prior to doing this swap, after I swapped in the 99 manifold I no longer had to run premium and never had any more pinging even whilst towing my camper trailer offroad in warm to very warm conditions on regular unleaded, I still ran the TBS though.
I was informed by several people that this swap 100% does NOT work and that my findings were imaginary especially re the premium unleaded part, strangely though none of these people had been in my car let alone drive it.
I must add that later on I found that my OBD1 engine was down on compression (not sure how that would make it ping, should be the opposite), I have since swapped in an OBD2 engine with 50% more compression and added the matching "normal" manifold and all the OBD2 system, I haven't revisited the manifold swap since as all the dyno reports etc that I have seen suggests that this swap on the OBD2 isn't the way to go.
Good luck with it.....

[junglejuice]

Here it is with the 99 manifold with OBD2 engine with OBD1 controls...



What you can't see in the above pic is the power steering pump bracket, I used the OEM bracket from a Zg as I deleted the mechanical fan...

[emac]

Thanks JJ did you have to put spacer between the PS pump and the manifold like gojeep did

[junglejuice]

I initially modded a bracket and used a spacer due to the offset being different between OBD1 and OBD2 pumps, now I'm using the Zg bracket pictured above I'm using an OBD2 pump so no longer need modded anything...

[emac]

Ok got it done, altogether a real pain of a job, was it worth it , probably

Just some background, my car has extractors and. 2.5 inch system front to back including cat, it has 4.10 gears and 31 inch tyres

No mechanical fan ( twin electrics)

And it has 420000 km on it 1994 obd1

It started straight up and idled perfect when done
I reset the ECU and test drove it seemed OK, came home and cleaned up and took it for a longer drive,

It's hard to quantify the results, it's very subtle, but it seems to have a much smoother power delivery, idles smoother, seems to pull stronger around 2000 rpm which is where I spend most of my time

Highly untechnicial but it seems happier and more willing

I previously had a throttle body spacer and I've left it there as well ( and no I don't care what all the so called experts say it worked on my previous setup)

Any way would I recommend this mod, probably, but only after exhaust upgrade, electric fan upgrade, and gears especially if running 31 in or larger tyres

That said I'm very pleased with the outcome

[rainman]

Originally Posted by emac

Ok got it done, altogether a real pain of a job, was it worth it , probably

Just some background, my car has extractors and. 2.5 inch system front to back including cat, it has 4.10 gears and 31 inch tyres

No mechanical fan ( twin electrics)

And it has 420000 km on it 1994 obd1

It started straight up and idled perfect when done
I reset the ECU and test drove it seemed OK, came home and cleaned up and took it for a longer drive,

It's hard to quantify the results, it's very subtle, but it seems to have a much smoother power delivery, idles smoother, seems to pull stronger around 2000 rpm which is where I spend most of my time

Highly untechnicial but it seems happier and more willing

I previously had a throttle body spacer and I've left it there as well ( and no I don't care what all the so called experts say it worked on my previous setup)

Any way would I recommend this mod, probably, but only after exhaust upgrade, electric fan upgrade, and gears especially if running 31 in or larger tyres

That said I'm very pleased with the outcome

I found very similar results when I did the same mods. IMHO bang for buck mods on the obd1 xj's are electric fan, exhaust, intake with a bored out tb. Do the injector upgrade at any point. Rather than muck about with the old ones.