Last two problems with my TR, Need help...

i had a similar problem on my 328. it went away on its own after a few drives. how long have you had this problem? mine happened after the car had been sitting for a while. drive it most of the next week and see what happens.

 

Sounds like it could be an adjustment screw on the throttle body. I had a similar issue for a bit of time. It could also be a a cold start valve that is staying open.

 

Not so sure a TPS problem would cause the idle RPM to be bimodal, but why not readjust/check mechanically and check electrically?

If the TPS isn't working electrically, it can cause stalling when coming to a stop (but not sure if this is what you are reporting).
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Have a look at pivot were the gas peddle is connected in the footwell

I have had this on my 308,

It accumulates dirt and every thing else,

Good luck

 

That thing sure is dirty...a little carb cleaner would remove that varnish and crud which would make it look much better...

 

Check the throttle cable with the throttle bodies closed, there should be a tiny bit of slack - it should not be taught. Also look at the return springs on each throttle body to see that things are clean and move freely from wide open to fully closed. Try cleaning and lubricating things in this area. If an Aux. Air Valve is sticking open, an easy test is...while the engine is idling at 1500rpms or so....pinch shut the air lines feeding into the lower air diffuser housings, if the idle speed goes down then you've found your problem. But I sorta doubt it's one of the aux. air valves. I would look closely to see that both throttle bodies are synchronized, meaning they open and close at exactly the same time. Verify the throttle cable tension at rest. Clean and Lube stuff. Let us know how things work out.

 

That isn't his engine.
Its just a photo used for reference.

The extra fitting is the give away that it is Euro spec.

 

Since your now seeing idle-hunting, try and adjust the air bypass screws back to their original positions if you can remember them, because you now have an idle imbalance between the cylinder banks. As for checking the throttle butterflies, I wouldn't do that until I was sure that the throttle linkages are cleaned and lubed, and synchronized properly. The only way to actually see the throttle butterflies is to remove the upper intake plenums - not a big deal to do - but they are not usually the problem.

 

Is it possible that there is a vacuum leak?

 

So far the way things seem to have progressed in this thread, I don't think a vacuum leak has been created - at least not yet A vacuum leak would make adjusting the fuel mixture at idle/driving impossible. A simple way to check for a vacuum leak is to spray something (like wd-40 or other product - that when injested will change the idle speed or characteristics of the engine) at all the intake system joints and observe any changes. If the car was running very well in all regards except for the "sticky throttle" syndrome, I feel it's a mechanical issue somewhere. It could even be the throttle cable itself. I would do a methodical check, clean, lube, and adjustment of everything, and only when I'm sure those things are right would I look elsewhere.

I hope you find the problem. Let us know if you have anymore questions, and keep us posted....

 

I'm happy to help if I can - I'm just an enthusiast like most here on fchat. Here is something very quick and easy to try. Take a look at the throttle cross-shaft that links both throttle bodies and the accelerator cable together. Loosen, but do not remove, the two 13mm nuts that secure the end bearing brackets to the lower air diffuser housings...loosen the nuts maybe 2 or 3 turns only...and then see if things are still binding at the point of throttle closure.

I've seen times where I'm assembling everything on top of a TR motor back together and tightening things down, and notice that the throttles will stick or bind just like your describing. Sometimes I've had to loosen and carefully retorque several bolts and nuts back down, and voila....the binding is gone.

Try this and see what happens.....Good Luck...!

 

Not to brag.......but..........I showed this "fix" to the Seattle Washington Ferrari dealer a couple months ago when I was in their showroom looking at a TR they had for sale. The salesperson was commenting that the car was a pain to get in the showroom because it would idle high and that the pedal needed to be "flicked"and then it would idle properly. I told him I had a pretty good idea what it was and he then.......unlocked..........the doors so I could show him.....................We had a great conversation 45 minutes, after that "moment", about a variety of subject concerning the world of automobiles.............funny how if your wearing an Ozzy Osbourne hoodie and faded black jeans how your "treated", and then when they see you actually do know a bit about their trophy cars how quickly Ralph Lauren and Rolexs all of a sudden are not the uniform required...............anyway............

What sometimes happens is that the aluminum sheet metal that is carpeted and is part of the center console/tunnel side panels gets bumped ever so slightly and causes the aluminum to bend just a tad and it interferers with the pedal retracting all the way back to an idle position. I had this same problem after I re-did my carpeting and installed a stainless steel console control panel........... and I lubed and I dismantled and I adjusted and I replaced and I cleaned and I repeated every step on my TR's throttle linkage path. Finally I reached behind the panel and pulled it towards me a bit and problem was fixed................10 hours of R & R...10 seconds to "fix".................Hopefully this is the problem..........Kerry
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Very infrequently mine does this too. A little higher, around 2000 RPM, and then a blip of the throttle and she's back to 1050 pefect.

I've lubed and checked the path also so might look at Kerry's fix next.

Thanks all.

 

Do this:

Check your gas pedal. When the car starts to surge, pull the gas pedal forward (towards the driver's seat). I bet you that the idle will go back down. If that is the cas then your pedal needs some adjusting. Just speaking from experience.