New gasket needed when replacing Throttle Position Sensor?

[RickBlaine]

Howdy gang,

I am going to replace the throttle position sensor (TPS) on my 1991 240sx next week. In order to do this, I will be removing the throttle body as I can't see a way to do it otherwise.

1) What else should I clean/replace while I remove the throttle body in order to swap the TPS? In other words, what else is in that area that will need attention anyway?

2) Does the throttle body need a new gasket? It has never been replaced. Where to get this gasket?

3) If you know of a good write-up/video to do all this, please point me in the right direction. The majority I've seen seem to be broken links or not very descriptive.

Thank you!

[centralcoaster33]

Hi Rick, I've done some work in the same area on my 240's. Yeah, you're gonna want to buy a gasket for the TB. The old one will inevitably be stuck half on the TB and half on the intake. I got mine from AutoZone, but it's been a while so I don't recall if I had to order and wait or if they had one in stock. It's cheap and will be a perfect fit.

With TB off, you have better access to the PCV area, so maybe a new valve in there. You could replace a few of the hoses in that area. Like, that one from the valve cover to the intake. There will be a lot of old oil built up in the TB area, so getting that cleaned out will be nice. You'll be able to get partially into the intake area and wipe out some goo. The plastic parts can be cleaned nice with some soaking in Dawn and warm water. You can inspect your parts for leaks (check the plastic tube thing connected right to the TB). Might as well put a new filter in the air box and spray your MAF with a little MAF cleaner. Check your small coolant lines that go through the TB. Have a voltmeter handy to set the TPS voltage when you're done. Plan to check timing and idle when that is done.

That's all I could think of off the top of my head. No video or images that I'm aware of, but I also didn't look for ones that I'm not aware of.

[PapaSmurf2k3]

I don't recall having to remove the throttle body to replace the TPS, but it's been forever. I thought there were just 2 screws and a harness connection, no?

[centralcoaster33]

True, in most circumstances, but not all. I'm not sure what his thinking is about having to remove the TB, but maybe he does. The first time I ran into this I needed to replace TPS, the screws on there were literally screws, not bolts, so there was no way to fit a phillips to the end of them without removing the TPS. I even bought one of those 90 degree bent screwdrivers, but couldn't apply the necessary force to turn the screws. TB came off that time. Another time on another 240sx the TPS had bolts with hex heads, so it was easier, but still a pita and removing the TB would have made access a little easier still, though it was not necessary that time. The current 240sx has the hex bolts, but I was doing other things along with it, so the TB came off that time as well.

[RickBlaine]

Thank you, Gents!

As for the TPS removal, I could get a 10mm wrench and remove the bolts. The problem is the TPS mechanism itself. As I try to slide it "out" to the right, the last 1/8 of an inch of it is still in the throttle body while the TPS is hitting one of the coolant hoses to the right. Even loosening one end of that coolant hose, it was not enough. I tried for two hours and gave up.

Several threads here state that you can get by by simply removing the 4 throttle body bolts and then pulling the throttle body towards you and a half inch to the left- no removal or adjustment of the throttle cable needed. Thanks to @centralcoaster33, I shall go all the way and clean up other items as long as I am in the area.

Going to do that and my water pump this week....original Nissan water pump started leaking out of the weep hole last week. After 26 years, it said goodbye!