L-Jet throttle body question Options

[Rob-O]

A few months back I reinstalled the L-Jet back into my '74. I had the throttle body reworked at that time (see pics). There are two arms on the TB. One attaches to the barrel but/accelerator cable and the other to a spring (return spring of some sort?). After installation I was at an event with Clay Perrine and he said that the spring was on incorrectly (I had it connected to the plenum, instead of the firewall). I connected it to the firewall but I'm not sure what that arm is controlling now that I've got the TB installed on the car and can't see its function. I don't know if the spring is the wrong one or just tired. But the arm on the TB that the spring is attached to doesn't seem to do much. The spring doesn't really return it to the idle resting position when the throttle closes.

(IMG:style_emoticons/default/confused24.gif)

[timothy_nd28]

That looks pretty.

[bretth]

I have two 1.8 motors. The one in my car has the spring connected at the trunk wall and the extra motor has the spring connected at the plenum. My car is a 75 and i think the extra motor is from a 74 because it has an extra vacuum port that the 75 doesn't.

Brett

[ClayPerrine]

Probably a tired or stretched spring.

The one on the shaft is the secondary spring. It is used to return the throttle if the primary spring breaks. The factory didn't do this on the 73 and older cars. Starting in 74, the 2.0 and the 1.8 got secondary return springs.

Use some berrymans b12 to clean the shaft, and put on a new spring.

[Rob-O]

The TB spring is closing the throttle plate, but if I understand Clay, the secondary spring should be closing the the lever it's attached to as well. If so then my spring is toast. I can actuate the secondary arm by hand and it feels smooth. That shaft is clean, I don't think it needs to be lubed (yes I heard it but there was no other way to type it!).

Clay, you're the admin, move this to the Sandbox if it's going south!

[Rob-O]

That looks pretty.

Thanks. Not my work though. Phil Eslin in New Mexico. Got his info from the Samba. Bead/sand blasted, rebushed, replated, bored over 1mm, custom stop on the outside so that the butterfly isn't what is the stop. Over the years the butterfly wears a spot into the TB housing and causes a sticky pedal feel coming off idle.

Pricey work. I think I was right at $300. Heck, I could get some custom gauges for that amount! Oh, wait, that box is already checked! (IMG:style_emoticons/default/smile.gif)

[malcolm2]

Pulling against the cable. How else could it be?
Mine is with Phil now too. This one is a loaner. Phil said he had no cores, so he had to rebuild mine and it would take 4 weeks.... I had to keep driving, so I found a generous World member. His TB is working great.

[ndfrigi]

I've been reading this thread since it started and now I would like share mine.
Since 2011 I've been driving mine without extra spring and it work well and my idle goes back to my normal idle. The only concern I have is same as above mentioned that the trottle flap kinda stick inside and a little sticky when I accelerate from idle but the rest of the pedal down to floor is all good. Hope to have a budget soon for the same rebuild at the 1st picture and to get rid of the ugly dirty looking engine. But the good thing I have no even a single oil leak now after fixing/replacing my rear main seal.

[Porschef]

Try to get a cover for your tranny console.

Looks good

[malcolm2]

I don't know if the spring is the wrong one or just tired. But the arm on the TB that the spring is attached to doesn't seem to do much. The spring doesn't really return it to the idle resting position when the throttle closes.

(IMG:style_emoticons/default/confused24.gif)

I was curious about what the extra spring does too. While the TB was out and "on the bench", I would push the flat lever (with the external spring on it), simulating the work of the external spring.

I would then pull on the accel cable lever (simulating opening the throttle). Strangely enough it seemed that it was easier to pull the accel cable lever when the external spring lever was fully pulled. (IMG:style_emoticons/default/blink.gif)

Maybe that is what this little spring does, it eases the work of your FOOT?

No measurements made, just my finger in the wind "feeling".

If I had a fish scale, I could try the test again in a few weeks when my TB returns.

[ndfrigi]

Try to get a cover for your tranny console.

Looks good

Is this a reply for me sir? if yes, i do have cover for it. thank you!

[jim_hoyland]

I don't know if the spring is the wrong one or just tired. But the arm on the TB that the spring is attached to doesn't seem to do much. The spring doesn't really return it to the idle resting position when the throttle closes.

(IMG:style_emoticons/default/confused24.gif)

If I had a fish scale, I could try the test again in a few weeks when my TB returns.

Whats the turn-around time ( approx.) for Phil to do the rebuild ? Curious... (IMG:style_emoticons/default/popcorn[1].gif)

[Rob-O]

Mine was about a month IIRC.

[malcolm2]

I don't know if the spring is the wrong one or just tired. But the arm on the TB that the spring is attached to doesn't seem to do much. The spring doesn't really return it to the idle resting position when the throttle closes.

(IMG:style_emoticons/default/confused24.gif)

If I had a fish scale, I could try the test again in a few weeks when my TB returns.

Whats the turn-around time ( approx.) for Phil to do the rebuild ? Curious... (IMG:style_emoticons/default/popcorn[1].gif)

He quoted me 4 weeks. I am 1/2 way home. He gave me an update last week. Everything is back from plating and I assume he is on schedule. BTW, I had a small collection of TBs that I accumulated while getting my FI working. He gave me some credit for them.

[malcolm2]

Try to get a cover for your tranny console.

Looks good

Is this a reply for me sir? if yes, i do have cover for it. thank you!

Hey, what is the benefit for installing the clutch cable pulley parallel to the ground on that orange angle plate?

BTW it looks good under there.

[ndfrigi]

Try to get a cover for your tranny console.

Looks good

Is this a reply for me sir? if yes, i do have cover for it. thank you!

Hey, what is the benefit for installing the clutch cable pulley parallel to the ground on that orange angle plate?

BTW it looks good under there.

Hi sir, I think that kind of clutch pulley bracket is just to give space for some headers. I didn't see any difference how the clutch work. I just used it since I have it from my other 914 before.

[ClayPerrine]

The spring on the throttle shaft is a federally mandated safety feature. The one that goes to the engine tin was the original design. But if it broke, the throttle would not return. NTSB mandated secondary throttle return springs on all 1974 and newer cars.

So they added the one around the shaft. It will return the throttle if the one to the tin breaks.

[malcolm2]

The spring on the throttle shaft is a federally mandated safety feature. The one that goes to the engine tin was the original design. But if it broke, the throttle would not return. NTSB mandated secondary throttle return springs on all 1974 and newer cars.

So they added the one around the shaft. It will return the throttle if the one to the tin breaks.

that certainly explains why it does not seem like it does anything..... the govm'nt!

[echocanyons]

The spring on the shaft on my 1.8 broke and I had the secondary spring attached correctly and it would not close the throttle body.

Anyone know where to locate a new shaft spring?

[Rob-O]

The spring on the shaft on my 1.8 broke and I had the secondary spring attached correctly and it would not close the throttle body.

Anyone know where to locate a new shaft spring?

I just replaced mine yesterday. I picked it up at ACE Hardware, in the trays with the nuts and bolts. It was slightly longer (in the compressed state) than the factory spring, but had more tension. I had to clip the ends to match the factory spring. The factory springs had hook ends. The replacement had rings. But a pair of diagonal cutters made quick work of that. I'll snap a photo and post here in a bit.