Fiat Coupe Forum
- Founded by Kayjey & James Northam
- Funded by the Club for the benefit of all owners
Fiat Coupe Club UK
join the club
Fiat Coupe Forum
 
» Announced
    Posting images


» Related sites
    Main club site
    fiatcoupe.net


» External data
    owners listed
 
Who's Online Now
4 registered members (jaaps2, 386ka, Scuderia, ash_p), 93 guests, and 4 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums67
Topics110,411
Posts1,310,513
Members2,170
Most Online731
Jan 14th, 2020
Top Posters(All Time)
barnacle 32,305
stan 32,098
Theresa 22,924
bockers 21,019
PeteP 19,350
JimO 17,908
Nigel 17,201
Jim_Clennell 16,346
nismo 15,137
RSS Feeds
Club Events
Club Information
Track Events
Rolling Road/RWYB
Social Events
Non-UK Events
Coupé Related Chat
Coupé Spotting
Coupé News/Press
Buying/Selling Advice
Insuring a Coupé
Basic FAQ's
How to Guides
Forum Issues
Technical Problems
General Maintenance
Styling
Tuning
Handling
ICE and Alarm
Coupés for Sale
Coupés Wanted
Parts for Sale
Parts Wanted
Group Buys
Business Forum
Other Vehicles for Sale/Wanted
Other Items for Sale/Wanted
Haggling/Offers
Ebay links
Other Cars
Other Websites
General Chat
Previous Thread
Next Thread
Print Thread
Throttle Angle readings #1637446
10/12/2019 08:44
10/12/2019 08:44
Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Kelv27 Offline OP
Forum is my job
Kelv27  Offline OP
Forum is my job

Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Whether it is with the Sykes Pickavant ACR or Multiecuscan, I remember being able to read throttle angles without the engine running. Doesn't seem to be the case anymore. Anyone knows why that is the case?



Re: Throttle Angle readings [Re: Kelv27] #1637450
10/12/2019 10:15
10/12/2019 10:15
Joined: Dec 2005
Posts: 7,333
Lightwater, Surrey, UK
DaveG Offline
Club Member 311
DaveG  Offline
Club Member 311
Forum is my life

Joined: Dec 2005
Posts: 7,333
Lightwater, Surrey, UK
Presumably you have the ignition on and have established a connection with the ECU, and can get other parameters like air and coolant temps, etc.? I think you get TPS voltage as well as opening degrees? Maybe the TPS is faulty..but I'm sure you would have noticed that?


1996 Portofino 20vt & 2000 Pearl White Plus
1985½ & 2016 2017 Fiat 124 Spider + XF Sportbrake
Re: Throttle Angle readings [Re: DaveG] #1637452
10/12/2019 10:49
10/12/2019 10:49
Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Kelv27 Offline OP
Forum is my job
Kelv27  Offline OP
Forum is my job

Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Originally Posted by DaveG
Presumably you have the ignition on and have established a connection with the ECU, and can get other parameters like air and coolant temps, etc.? I think you get TPS voltage as well as opening degrees? Maybe the TPS is faulty..but I'm sure you would have noticed that?


Yes, ignition on and connection all established...just that opening degrees won’t be shown until engine is fired up. TPS is working as it should I suppose? Or else it wouldn’t be showing readings (with engine running) and driving as normal.



Re: Throttle Angle readings [Re: Kelv27] #1637736
22/12/2019 10:07
22/12/2019 10:07
Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Kelv27 Offline OP
Forum is my job
Kelv27  Offline OP
Forum is my job

Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Anyone? What are you guys experiencing with your code readers?



Re: Throttle Angle readings [Re: Kelv27] #1637740
22/12/2019 11:07
22/12/2019 11:07
Joined: Dec 2005
Posts: 3,726
Pothole City
GrahamL Offline
Forum is my job
GrahamL  Offline
Forum is my job

Joined: Dec 2005
Posts: 3,726
Pothole City
Yes, you should be able to get throttle position degrees and voltage readings with ignition on without starting engine, on the ACR4.

Re: Throttle Angle readings [Re: GrahamL] #1637760
22/12/2019 15:39
22/12/2019 15:39
Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Kelv27 Offline OP
Forum is my job
Kelv27  Offline OP
Forum is my job

Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Originally Posted by GrahamL
Yes, you should be able to get throttle position degrees and voltage readings with ignition on without starting engine, on the ACR4.


Thanks for confirming that Graham. I don’t seem to be able to do that anymore... any idea on why that is the case? confused



Re: Throttle Angle readings [Re: Kelv27] #1637761
22/12/2019 15:45
22/12/2019 15:45
Joined: Dec 2005
Posts: 3,726
Pothole City
GrahamL Offline
Forum is my job
GrahamL  Offline
Forum is my job

Joined: Dec 2005
Posts: 3,726
Pothole City
What readings exactly is it giving for voltage/angle with engine off, even if they don't change with pedal movement?

If it's giving good readings with engine started I wouldn't be too worried, maybe dodgy TPS or wiring?

Re: Throttle Angle readings [Re: Kelv27] #1637763
22/12/2019 16:11
22/12/2019 16:11
Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Kelv27 Offline OP
Forum is my job
Kelv27  Offline OP
Forum is my job

Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Off-hand I can’t remember what the readings are with engine off but I remember it being normal. I don’t have any running issues. Just that it’s very difficult to see what the WOT readings are with engine running and revving the nuts off it. I’ve tried other TPS as well so unlikely to be that. Also tried measuring another car and it’s also doing the same thing of not giving readings unless the engine is running.



Re: Throttle Angle readings [Re: Kelv27] #1637765
22/12/2019 16:44
22/12/2019 16:44
Joined: Dec 2005
Posts: 7,333
Lightwater, Surrey, UK
DaveG Offline
Club Member 311
DaveG  Offline
Club Member 311
Forum is my life

Joined: Dec 2005
Posts: 7,333
Lightwater, Surrey, UK
I just tried on my Porto 20vt and can get voltage and angle readings on the ACR4 with just ignition on, but engine not running. Although at WOT it was only reading 62° (and 4.4V) whereas I thought WOT was something like 84° The cars in bits at the moment so don't want to start it in case there's something missing (no brakes at the moment for example). I'll try on the Plus if I get a chance.


1996 Portofino 20vt & 2000 Pearl White Plus
1985½ & 2016 2017 Fiat 124 Spider + XF Sportbrake
Re: Throttle Angle readings [Re: Kelv27] #1637767
22/12/2019 17:18
22/12/2019 17:18
Joined: Dec 2005
Posts: 3,726
Pothole City
GrahamL Offline
Forum is my job
GrahamL  Offline
Forum is my job

Joined: Dec 2005
Posts: 3,726
Pothole City
Just tried mine and got exactly the same readings as DaveG above and I can't currently start engine either.

Suspect it's just a "feature" of the ECU.

When I fitted a new TPS years ago I was definitely able to test to >85 degrees with engine off and adjusted throttle cable/pedal accordingly. The ECU manual isn't exactly that clear on which TPS parameters are available with only ignition on and which need engine running, but it does show that to read *all* the TPS parameters the engine has to be running and only one seems to be available with engine off.

The ECU handles Absolute angle , Relative angle (Absolute Angle - minimum threshold) and voltage on potentiometer, whereas the ACR4 only shows angle and voltage so it's not showing everything anyway. It doesn't say how the "minimum threshold" is calculated but maybe that has something to do with it and the difference with engine on/off. Looks like it may be only capable of giving the absolute angle with engine off and absolute and relative with engine running.

Re: Throttle Angle readings [Re: Kelv27] #1637770
23/12/2019 00:31
23/12/2019 00:31
Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Kelv27 Offline OP
Forum is my job
Kelv27  Offline OP
Forum is my job

Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Similarly, years ago I adjusted my WOT angles exclusively with the engine off through the the ACR. Themaximum was able to see it to was about 82 or 83 degrees. Never been able to go beyond that.

I can’t work out what changes I did since then which would alter this capability. I’ve never replaced my ECU (only the chip). The TPS was the same one as well.

Multiecuscan also did not allow me to see it with just ignition on.



Re: Throttle Angle readings [Re: Kelv27] #1637823
27/12/2019 14:10
27/12/2019 14:10
Joined: Dec 2005
Posts: 3,726
Pothole City
GrahamL Offline
Forum is my job
GrahamL  Offline
Forum is my job

Joined: Dec 2005
Posts: 3,726
Pothole City
Got to the bottom of this for my coupe anyway... it was because the battery had been disconnected and engine not started before checking the readings.

Probably the "minimum threshold" value that's used by the ECU to calculate the relative throttle angle is lost when power is disconnected and only re-calculated when the engine is running.

Previously max throttle reading was 62 degrees, but with engine started and rev'd slightly then switched off it was showing 82 degrees at full open throttle.

Re: Throttle Angle readings [Re: Kelv27] #1637828
27/12/2019 22:18
27/12/2019 22:18
Joined: Dec 2005
Posts: 32,305
Hemel in the Hempstead
barnacle Offline
Club Member 18 - ex-Minister without Portfolio
barnacle  Offline
Club Member 18 - ex-Minister without Portfolio
Forum Demigod

Joined: Dec 2005
Posts: 32,305
Hemel in the Hempstead
That would make an amount of sense. I recall that the widget would sometimes return the throttle without the engine running, and sometimes not... never investigated sufficiently to get to this level of detail, but the 20v throttle position is differential while the 16v throttle position is absolute.

Neil


[Linked Image]
Don't get no respect! [b]Coupe Fiat 1994-2000 - an owner's guide[/b] <-- clicky!
Re: Throttle Angle readings [Re: Kelv27] #1637829
28/12/2019 01:52
28/12/2019 01:52
Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Kelv27 Offline OP
Forum is my job
Kelv27  Offline OP
Forum is my job

Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Great find guys. That seems logical. However, I've not disconnected my battery for quite some. confused
Based on your description Graham, it doesn't seem like the ECU would take long to recalculate its values?



Re: Throttle Angle readings [Re: Kelv27] #1637830
28/12/2019 10:20
28/12/2019 10:20
Joined: Dec 2005
Posts: 3,726
Pothole City
GrahamL Offline
Forum is my job
GrahamL  Offline
Forum is my job

Joined: Dec 2005
Posts: 3,726
Pothole City
Originally Posted by Kelv27
Based on your description Graham, it doesn't seem like the ECU would take long to recalculate its values?


Yes, just one start.

Try the same series of actions I did :

1) Disconnect battery for a minute then re-connect
2) Connect ACR4 to diagnostic socket and battery
3) Switch on ignition and start engine
4) Make ACR4 connection to ECU
5) View "components" display, confirm throttle position value responding to pedal and throttle status value can show "idle" and "mid"
6) Switch off engine
7) Disconnect and re-connect cable from ACR4 end to reset it
8) Switch ignition back on but don't start engine
9) Make ACR4 connection to ECU
10) View "components" display, floor throttle pedal and confirm throttle position showing up to 82 degrees

Steps 7 and 8 may have been switched around, so try both ways if one doesn't work for you.

Re: Throttle Angle readings [Re: Kelv27] #1637836
29/12/2019 03:30
29/12/2019 03:30
Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Kelv27 Offline OP
Forum is my job
Kelv27  Offline OP
Forum is my job

Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Graham, I’ve followed your series of action diligently but the TPS angle remains unresponsive at ignition only.

TPS voltage was responsive though..



Re: Throttle Angle readings [Re: Kelv27] #1637837
29/12/2019 10:28
29/12/2019 10:28
Joined: Dec 2005
Posts: 3,726
Pothole City
GrahamL Offline
Forum is my job
GrahamL  Offline
Forum is my job

Joined: Dec 2005
Posts: 3,726
Pothole City
What range or number did it actually show on the ACR4 for throttle angle when moving the pedal?

Re: Throttle Angle readings [Re: Kelv27] #1637839
29/12/2019 13:49
29/12/2019 13:49
Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Kelv27 Offline OP
Forum is my job
Kelv27  Offline OP
Forum is my job

Joined: Jun 2007
Posts: 4,434
Malaysia..Glasgow at heart
Throttle voltage started at 0.3v... the angle was 0 and stayed 0...or did you mean with the engine running? With engine running, I think I saw it go to 83 degrees with a quick jab on the throttle.



Re: Throttle Angle readings [Re: Kelv27] #1637840
29/12/2019 16:25
29/12/2019 16:25
Joined: Dec 2005
Posts: 3,726
Pothole City
GrahamL Offline
Forum is my job
GrahamL  Offline
Forum is my job

Joined: Dec 2005
Posts: 3,726
Pothole City
OK, it's not doing the same as mine was then, I was getting a proper reading that changed but just not over the correct range.


Powered by UBB.threads™ PHP Forum Software 7.7.1
(Release build 20190129)
PHP: 7.3.12 Page Time: 0.019s Queries: 14 (0.008s) Memory: 0.8377 MB (Peak: 0.9780 MB) Data Comp: Off Server Time: 2020-01-18 11:51:42 UTC