Difference between S13 / S14 OBDI / S14 OBDII manifolds

[Kinesthesia]

As I mentioned in another thread, I'm about to replace my KA. My current engine is OBDI, and the new one is OBDII, I heard that I have to keep my current manifolds, but I'm curious to know why.

This is no big deal, but I'm curious what the differences are. I also have an S13 KA24DE.

I assume I could use the new injectors...

I thought I remembered something about the OBDII exhaust manifold having two O2 sensors... if that were true, I could throw in a wideband for one thing.

I have no idea what the difference in the intake manifolds at all....

Thanks

[koukiKA240]

I dont have a working s13 with s14 but i am in the process of doing so. I have a 91 240 engine that i have built up and am mating with 95 240 intake manifold. I was fortunate enough at the time to have a running s14, and a running s13 KAT to base the vacume situation off of. What i have done so far is trace the 3 vacume lines that come out the front of the manifold next to the Throttle body. The 2 on the left i beleive go to the gasoline coal evaporator thing, or i could take that off and route it to the intake after the turbo. The larger one on the left goes directly to the intake right next to the trottle body, and if i wanted i could T it off to connect to the valve cover as well, but in fear of oil getting in the intake im going to run a small air filter on the valve cover. The other differencei noticed was on the back of the head of the s13 the plate that holds many hard vacume lines is far larger and more complex than the s14 due to absence of vacume opperated flaps on manifold. Also the heater hose return line comes out the back of the s13 manifold and out the side of the s14 manifold. This was fixed easily by buying a s14 heater hose return line and mating it to the old line. The pre bent rubber hose actually work well with the setup. If i am way off someone PLEASE let me know. I havnt started the engine yet but will be shortly. It would save me a headache ans some time to know that it is NOT POSSIBLE to run a s14 Intake manifold on S13. AND BTW i have blocked off my egr and have removed my AAC, seeing as it doesnt seem to get below 70 in houston and im running out of cash to buy a new one. I plan on runnning my wastegate off of the Fuel pressure regulator vacume line. Hope this has at least illustrated the differences, this is to my knowledge and good luck.~Sam

[:: orion ::]

Differences in intake manifold:

A few spots to mount sensors onto...and the TPS sensor (easiest to just swap the whole TB), and coolant temp sensors. Otherwise identical.

The OBD sensors you have on the '95 manifold will all bolt onto the new manifold...but you'll have a few open "bungs" that would have had solenoids and such munted on them from the factory. No big deal, leave them open. They will no introduce a vaccum leak, they are external...

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As for the exhaust manifold...they are drastically different from S13 to S14...but ALL S14 exhaust manifolds are identical.

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The info you read was probably with respect to putting an S14 motor into an S13...there, you'd just use the whole S13 manifold b/c it;'s easier than swapping all the soensors over. That may be easier in your case as well...you '95 intake manifold already has everything in place, why not just swap it over in one shot? There's no performance advantage either way...

- Brian

[Kinesthesia]

I was told that I have a bad EGR solenoid in my current engine, is that something that's on the manifold or the block ?

Either way, can I use the new OBDII one with my OBDI setup ?

I do think I'll just unbolt the manifolds and swap out the long block. But afterwards, I may take either the new OBDII or my old S13 intake manifold and clean it up really good and swap it in later on.

Thanks for the input.

[AZhitman]

Brian - Great info, your posts are always informative and helpful.

Sam, yours too.

[Kinesthesia]

Differences in intake manifold:

A few spots to mount sensors onto...and the TPS sensor (easiest to just swap the whole TB), and coolant temp sensors. Otherwise identical.

The OBD sensors you have on the '95 manifold will all bolt onto the new manifold...but you'll have a few open "bungs" that would have had solenoids and such munted on them from the factory. No big deal, leave them open. They will no introduce a vaccum leak, they are external...

The info you read was probably with respect to putting an S14 motor into an S13...there, you'd just use the whole S13 manifold b/c it;'s easier than swapping all the soensors over. That may be easier in your case as well...you '95 intake manifold already has everything in place, why not just swap it over in one shot? There's no performance advantage either way...

- Brian

Now that I've seen the new engine....http://www.ammerman.org/240sx/KA24DE/

I'm keen to use as much of the new engine as possible. Can you be more specific about the OBD sensors that will need transplanting and what's involved in swapping the TPS sensor, as the throttle body looks much much better than mine also.

Unless you think that I'm completely nuts, aside from just appearances, I assume with 100k fewer miles, the new intake manifold and throttle body have less gunk in them. I guess I could clean out the '95 manifold while moving it...

Thanks again for any input.