Hanging revs...Throttle position sensor? - Alfa Romeo Forum
You are currently unregistered, register for more features.    
 
Thread Tools
(Post Link) post #1 of 6 Old 14-09-14 Thread Starter
Status: -
AO Member
 
Join Date: Jun 2010
Location: United Kingdom
County: Cornwall
Posts: 93

Member car:

GTV

Hanging revs...Throttle position sensor?

The revs sometimes take a long time to drop down to the lower end of the rev range and when having a spirited drive and dropping down in preparation for some more tight or uphill sections the car can kangaroo a bit.( I have read that a lot of early direct injection and fly-by-wire cars of all makes can suffer from this)

The clutch is new and the car is well serviced.

A few questions:

Can i clean the TPS?
Can i disconnect it and drive the car, i read abut a similar issue on a ford and the guy disconnected it and the revs didn't hang then although idle was very low. I would use this to prove its the sensor and then buy a new one.

Regarding a new one is it easy to fit, ie just unscrew and unplug?

Thanks in advance

Shelly.
ShellyGTV is offline  
Sponsored Links
Advertisement
 
Status: -
AO Silver Member
 
Join Date: Apr 2008
Location: New Zealand
County: -
Posts: 2,605
What engine do you have? If you mean when you lift off the throttle the revs don't drop immediately like it should the first thing to check is for vacuum leaks in the inlet.
sprint_veloce is offline  
(Post Link) post #3 of 6 Old 15-09-14 Thread Starter
Status: -
AO Member
 
Join Date: Jun 2010
Location: United Kingdom
County: Cornwall
Posts: 93

Member car:

GTV

Alfa gtv 2.0 JTS.

Regarding your advice above do you mean that there could be a split in some of the induction pipework or a hose clamp not tightened enough?
ShellyGTV is offline  
Status: -
AO Silver Member
 
Join Date: Apr 2008
Location: New Zealand
County: -
Posts: 2,605
Yep that's the one.

Does the JTS even have a TPS?
sprint_veloce is offline  
Status: -
AO Platinum Member
 
Ralf S.'s Avatar
 
Join Date: Feb 2002
Location: The land that Time forgot
Posts: 13,057
On my CF1 Twin-Spark I had a clogged Idle Control valve. It sits on the throttle body... I dunno if the JTS has anything similar. Take it off.. clean it out carefully with WD40 and carb-cleaner etc.. it should/could be a small metal rotary valve... and re-try it..

There is a TPS reset procedure for T/Sparks.. I dunno if the JTS has one (a reset procedure) but it's worth looking to find one. It tells the ECU where the throttle is when "idle".


Ralf S.
Ralf S. is offline  
Status: "Ruby" has been Torpedoed!
AO Member
 
bazzbazz's Avatar
 
Join Date: Apr 2013
Location: Brisbane Australia
County: Queensland
Posts: 515

Member car:

Alfa 156

I'll bet it will be your PCV (Positive Crankcase Valve) valve sticking, it is after the throttle body, to the left of brake booster vacuum line.

The spring either breaks or loses its tension, or the shaft on the "golf tee" type valve gums up & sticks. The valve is only supposed to open at high RPM, if it sticks open you
will virtually have a air leak BEHIND the throttle body, causing higher RPM.

Link to replace it -

Gazza82's 1998 Alfa Romeo 156 TSpark 2.0

Baz
bazzbazz is offline  
Reply

Go Back   Alfa Romeo Forum > Supported Alfa Romeo Models > Technical & Vehicle Assistance > Engines (TS, JTS, JTD & V6)

Tags
hanging , position , revsthrottle , sensor

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome