Bx 16 valve tickover
Bx 16 valve tickover
Just aquired a 16 valver......Any one any thoughts as to a tickover that dosent adjust on the throttle body, the minimum it will reduce to is about 1200rpm when the car is hot. Any obvious places to start with first?? I am well experienced with bxs but all of mine have been diesel...any thoughts in the right direction would be appreciated...its a 1988 car that dosent have the cat converter...Many thanks.
Bx turbo diesel 1989
Bx 1.9 Rd estate 1989
Citroen Light 15 1952
Bx 17 TZD diesel turbo 1992
Xantia 1.8 16v
Bx 1.9 Rd estate 1989
Citroen Light 15 1952
Bx 17 TZD diesel turbo 1992
Xantia 1.8 16v
I would take a close look at the operation of the supplementry air device that normally allows air to bypass the throttle body when the engine is cold, as it sounds like this device may not be completely closing off when the engine is up to temperature. Quite a common problem as this device can get stuck up due to congealed oil deposits over time.
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Mike E (uk)
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mat_fenwick
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Obvioulsy it's got to be down to more air getting in than should be, so could be an air leak somewhere.
Mike, (on the 205 at least!) there is a screw on the throttle body that I believe sets the stop position for the butterflies, hence adjusting the idle speed.
Mike, (on the 205 at least!) there is a screw on the throttle body that I believe sets the stop position for the butterflies, hence adjusting the idle speed.
1993 1.9 TZD Turbo Estate
1996 3.9 V8 Discovery
1993 VW LT35 campervan
1985 Hyundai Stellar V8
2016 Hyundai iLoad
Has the car AC? Any idea of ECU system and number on the ECU box??
To possibly get a bench mark point before adjusting the mixture control, also, don’t take rpm dash reading as gospel.
If AC, disconnect the throttle quadrant linkage.
Disconect throttle cable and remove TB intake ducting.
Super glue a small length -2? of 5 amp fuse wire to a cocktail stick, not with a cherry on it!!
Unscrew the stop screw about 1-2 turns, but remember the original setting position.
Raise the TB main flap, insert the fuse wire on the central lower section. Very, very gently lower the flap onto the wire. Adjust the stop screw C/W until you’re able to just withdraw the wire,- pull very gently, breaks easily.
Reconnect the throttle cable, check AFM main flap for free movement and see if there’s any improvement. Adjust the stop screw no more than half a turn in any direction.
ECU controls idle speed around the 850 mark.. 950 rpm with AC, but small adjustments can be made.
Any wayward readings from CTS, ATS and sticking idle actuator can affect idle speed.
Adjustments of 1 turn only on the AFM mixture screw, C/W and A-C/W, may trim the tick-over. Again, remember the original setting.
Would recommend a CO check, gives an indication of problems with mechanical or electrical components.
Regards
To possibly get a bench mark point before adjusting the mixture control, also, don’t take rpm dash reading as gospel.
If AC, disconnect the throttle quadrant linkage.
Disconect throttle cable and remove TB intake ducting.
Super glue a small length -2? of 5 amp fuse wire to a cocktail stick, not with a cherry on it!!
Unscrew the stop screw about 1-2 turns, but remember the original setting position.
Raise the TB main flap, insert the fuse wire on the central lower section. Very, very gently lower the flap onto the wire. Adjust the stop screw C/W until you’re able to just withdraw the wire,- pull very gently, breaks easily.
Reconnect the throttle cable, check AFM main flap for free movement and see if there’s any improvement. Adjust the stop screw no more than half a turn in any direction.
ECU controls idle speed around the 850 mark.. 950 rpm with AC, but small adjustments can be made.
Any wayward readings from CTS, ATS and sticking idle actuator can affect idle speed.
Adjustments of 1 turn only on the AFM mixture screw, C/W and A-C/W, may trim the tick-over. Again, remember the original setting.
Would recommend a CO check, gives an indication of problems with mechanical or electrical components.
Regards
Hi Vanny,
Put your glasses on !!!!! Most probably the original lead seal is covering the screw, but…. you never know. I’m not sure with CAT models, you could be right.
The CTS adjusts injector pulse duration for hot and cold cranking.
ATS and CTS have very similar resistance readings stationary and should imagine ECU takes an average from both during starting, then the ATS trims the range of duration once running.
Kind Regards
Put your glasses on !!!!! Most probably the original lead seal is covering the screw, but…. you never know. I’m not sure with CAT models, you could be right.
The CTS adjusts injector pulse duration for hot and cold cranking.
ATS and CTS have very similar resistance readings stationary and should imagine ECU takes an average from both during starting, then the ATS trims the range of duration once running.
Kind Regards
Alastair,
A couple of additional points I forgot to mention.
When refitting the throttle cable, check for a small amount of slack.
Initially you could try running the car with the cable detached. Refit, and check for any alteration due to inner cable drag.
If the TPS is set incorrectly, this will indicate to the ECU the engine is running above the 850rpm mark and maintain a faster idle due to increased injector duration.
May require resetting.
There could be several possibilities, just need to work through one section at a time.
Regards
A couple of additional points I forgot to mention.
When refitting the throttle cable, check for a small amount of slack.
Initially you could try running the car with the cable detached. Refit, and check for any alteration due to inner cable drag.
If the TPS is set incorrectly, this will indicate to the ECU the engine is running above the 850rpm mark and maintain a faster idle due to increased injector duration.
May require resetting.
There could be several possibilities, just need to work through one section at a time.
Regards