Newbie Winter Projects: 1.7L D-Jet Punchlist, TPS and AAR rebuild tips? Options

[Stev914]

914 Pals:

I'm looking for newbie guidance on a couple of D-Jet related projects.

My '72 914-4 is about to take a Winter break in my heated garage. After getting much improved performance by adding a 123 distributor, there are two projects my local mechanic thinks would further improve matters, and I think I might be able to take them on myself (so does he).

- Rebuild the Auxiliary Air Regulator (AAR)
- Rebuild the Throttle Pressure Sensor (TPS) (e.g. replace the circuit board)

I am reasonably handy, but not a car guy. Yet. I think these two projects might be good "gateway" jobs to get more more comfortable. Because I won't be driving the car for a few months, these seem like manageable projects to keep me engaged with the thing.

Q. Any tips, tricks or precautions on these two projects?

Thanks,
Steve

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MORE DETAIL:

Here's more info about the car. This '72 has stock D-Jet, and I want to keep it (no plans to go carbs or do anything else). It was originally a 1.7L, but has new AMC heads and is now 1.8L. As I mentioned, I just upgraded to a 123 (4-R-V-IE) distributor. Apart from that, the engine is stock and I really want to keep it that way. The TPS mostly causes issues at about 50% throttle; I've already sort of learned where that is an can avoid it with my foot; that said, now that I am driving it a lot, I can only imagine it will get worse. The idle is also only an intermittent problem, but if I am putting the car away for 3 months, this might be a great time to do the refresh on both units. I realize I could probably just purchase rebuilt units, but this seems like a good way to dip my toe in the water. Please caution me if you think otherwise! I do like tinkering, but have never really worked on cars.

For AAR, Ian Karr's great video makes me think I could definitely do it.
https://youtu.be/cBdjLrxvBIM?si=xzCHIzgjlDNIaPiz

Barefoot Garage Jax video on TPS rebuild also makes me think this is within reach for me:
https://youtu.be/chqXHxYFCVw?si=v6S9t5o8J_pZq_D0

Finally, my operational assumption is that rebuilding these two components can't hurt (unless I screw it up some how). Even if they aren't contributing significantly to problems, we could file these projects into the "learning" and "preventative maintenance" categories.

[emerygt350]

The AAR is not working? Stuck closed?

The TPS is super easy. I seem to remember some mistakes with his rebuild instructions so I wouldn't take it as gospel. It really is so stupid simple you should be fine. Follow the 914rubber instructions with the new board. That said, all you may need to do is clean the contacts on your existing board.

[Ishley]

The Throttle Position Sensor board I purchasd came as a kit with pop rivets etc. You have to be careful drilling out the old ones and a had to get a new pop rivet gun as mine didn’t have the small size. Make sure the copper fingers hit during sweeping the throttle… like they did in the old one. Other than that it’s a couple hour project. You’ll need an ohm meter to set the position when assembled.

For the Aux Air Reg… remove it… squirt some wd40 inside… leave it over night. The next day apply 12volts and a ground. I used my battery charger on low. Wait 10 minutes to see if it closes… by blowing air thru it. If it closes you’re done. Oil once a year. If not then you have to take it apart and break it free and Clean it And reassemble/test.