Engine stalls after rev.

Hey Fred,

Not sure if this will help but read these two threads

http://www.ferrarichat.com/forum/technical-q/329848-testarossa-idle-problem.html

http://www.ferrarichat.com/forum/boxers-tr-m/266918-how-microswitch-setting.html

Jeff

 

If the OP has an '86 UK version, it is probably an F113A (K-Jet without Lambda) engine TR (so not much in those KE-Jet with Lambda threads would apply).

OP -- Can you please:

1. Confirm (or deny) it is an F113A engine TR?

2. Comment on whether this a new problem that occurred suddenly (i.e., it was OK, but the behavior has now suddenly changed), or has it always been this way (since someone last fondled all of its adjustments)?

 

Maybe the throttle is getting hung up when the idle is 1100. Then when you blip the throttle, it closes all the way against the idle screw adjust.

Shouldn't let the car sit so long. Injectors, and FDs can get clogged.

 

The comparatively high idle could be a sign of false air entering the intake through a failed seal, this can be checked using brake cleaner on the various joints, looking for idle changes.
There is also a possible problem with overrun shutoff. It could indeed be the throttle valve slamming too far when letting go of the throttle. This can also be caused by play in the throttle valve shafts.

This is the KE-jetronic system? Check here for a description on troubleshooting faults that often plague that system (warning, in German and don't be afraid of technical stuff): Sternzeit 107 - Anleitung zu Arbeiten an der KE-Jetronic. Or here for K-jetronic: http://www.zeepoort.nl/jetronic/bosch-k-jetronics.html

 

Steve,
You are a wealth of information on this forum. We all owe you a great thank, you and happy holidays!

 

Thanks for the kind words David. I guess I just enjoy hanging out with others experiencing the pleasure and pain of having an affair with a TR -- and it gives both

One thing that I've always found very impressive about K-Jet without Lambda is that it really doesn't have any electrics/electronics other than just +12V power to run the fuel pump(s) (and some minor functions like the WUR heaters and TTS system). Of course, this also means that there really isn't any simple electrical fault that can cause a K-Jet without Lambda engine to go from good warm running to still running but not running well warm (this is not the case with KE-Jet which has many possible electrical faults that can occur and cause that). K-Jet without Lambda does have some vacuum-operated gizmos (called vacuum limiting valves or vacuum bypass valves or just bypass valves) to prevent the system from going too lean under hard engine deceleration (like going from 5K RPM to closed throttle while going down a hill in gear) -- but going from a gentle 2K RPM stationary to closed throttle just doesn't seem to be in that league. Consequently, I'd more suspect more that it is just not really tweaked-up well so have no better thought than TR WSM Chapter D.

One simple thing you can do is to make a mark on the big hex heads of the air bypass screws of the throttle bodies and then count the turns required to fully close each (making the mark beforehand will allow you to return them to their original open adjustment position). Each should be open only something like 1/2~1 turn so if one (or both) are open something like ~4 turns or fully closed = obviously not tweaked up correctly. Good Hunting!

 

Steve's and Spicedrivers points are all good but it is also a symptom of the wrong idle air adjustment set up. CIS cars are for some reason prone to this. The idle speed should be adjusted to about 700RPM balanced air flow on the idle plate stop screws then raised to 1100 or so A/C off on the idle air bleeds @ the correct fuel mixture with O2s disconnected.

For whatever reason a good portion of idle air needs to be supplied by the idle air bleeds or stalling at a sudden release of the throttle at no load is common. BBi's were really bad for this but TRs do the same thing.