Ok so ive noticed this on my previous st205 and now on the mr2. I never fixed it completely on the st205 but i did have a general running fault which turned out to be a corroded ignitior. It still had the following problem much like the current mr2......
Im getting a hesitation feeling on very very gentle throttle at around the 2000rpm mark only. I think its more noticable from cold but to be honest i can feel it all the time.
Now only on the mr2 I also find the idle is slightly random. Starts at 1500rpm from cold and sometimes creeps up to 2000rpm. Drops to 900-950 when warm and occasionally sticks at 1100rpm.
Its had new dizzy cap, rotor arm, leads, plugs, coolant temp sensor, lambda sensor. I physically checked dizzy cap and arm last week to find loose rotor arm thanks to cross threaded screws which i replaced. Car now feels far more responsive in general but the slight niggles remain....only things left to change are dizzy and fuel injectors/regulator
Coolant sensor resistances are all in spec as engine warms up and lamda switching fine. No air leaks on intake system. No engine error codes. Wiring all checks out and ive cleaned up earth points on top of gearbox and back of inlet manifold
[Mk2] [Generic] Hesitation at 2000rpm
Moderators: IMOC Moderators, IMOC Committee Members
Re: [Mk2] [Generic] Hesitation at 2000rpm
Interested to see where this goes...
I'm looking at making a video of mine for the purposes of the other thread, see if anyone has any smart ideas based on that. FWIW, I'm still thinking TPS/Idle Valve.
I'm looking at making a video of mine for the purposes of the other thread, see if anyone has any smart ideas based on that. FWIW, I'm still thinking TPS/Idle Valve.
Re: [Mk2] [Generic] Hesitation at 2000rpm
Compression is 200psi across cylinders. Adjusted ignition timing today and popped a fuel cleaner in and ive got to admit it feels miles better and hot idle is 800rpm!
Plug in cyl 1 wasnt overly tight but i dont think it was loose enough to cause a problem
Plug in cyl 1 wasnt overly tight but i dont think it was loose enough to cause a problem
Re: [Mk2] [Generic] Hesitation at 2000rpm
Id say ignitor or a bad earth.
Had this on mine and it was a combination of both.
Had this on mine and it was a combination of both.
Re: [Mk2] [Generic] Hesitation at 2000rpm
So to go with my ongoing high idle problem this has reared its ugly head to the point where when cold only it will not rev past 3000rpm, starts bucking and missing at around 2000-2500 on a gentle throttle and then wont accelerate at all
Re: [Mk2] [Generic] Hesitation at 2000rpm
Coil pack or ignitor perhaps? Seems you've covered most other ignition components.
Re: [Mk2] [Generic] Hesitation at 2000rpm
covered those as well
Re: [Mk2] [Generic] Hesitation at 2000rpm
The severe hesitation was induced by fitting a faulty lambda probe whilst trying to fix a high cold idle runs fine with no lambda probe
-
- IMOC Affiliated Trackday Organiser
- Posts: 10506
- Joined: Tue Jan 25, 2005 9:49 am
- Location: South Yorkshire
Re: [Mk2] [Generic] Hesitation at 2000rpm
dan4 wrote:The severe hesitation was induced by fitting a faulty lambda probe whilst trying to fix a high cold idle runs fine with no lambda probe
What's a "lambda probe"?
Re: [Mk2] [Generic] Hesitation at 2000rpm
lambda sensor, oxygen sensor
-
- IMOC Affiliated Trackday Organiser
- Posts: 10506
- Joined: Tue Jan 25, 2005 9:49 am
- Location: South Yorkshire
Re: [Mk2] [Generic] Hesitation at 2000rpm
dan4 wrote:lambda sensor, oxygen sensor
Oh, OK. But you said:
dan4 wrote:lamda switching fine.
And then you said:
dan4 wrote:The severe hesitation was induced by fitting a faulty lambda probe
BTW, the engine will not be operating correctly without a working O2 sensor.
Re: [Mk2] [Generic] Hesitation at 2000rpm
Oh sorry "specialist" my bad
-
- IMOC Affiliated Trackday Organiser
- Posts: 10506
- Joined: Tue Jan 25, 2005 9:49 am
- Location: South Yorkshire
Re: [Mk2] [Generic] Hesitation at 2000rpm
dan4 wrote:Oh sorry "specialist" my bad
Pleasure!
Re: [Mk2] [Generic] Hesitation at 2000rpm
dan4 wrote:Oh sorry "specialist" my bad
Why put a sarcastic insult at someone trying to help you? Either the lambda is working fine or its not, thats why it was questioned.
Re: [Mk2] [Generic] Hesitation at 2000rpm
I very much doubt he is helping or has helped, infact it appeared he didn't know much about the systems ability of testing using vf1 diagnostic terminal, its 0v/5v lambda switching test or fuel trim application. The original lambda switched ok or at least appears to when tested however its heater circuit has no resistance. The next lambda probe that was fitted didn't switch at all and created a crazy misfire and inability to rev past 3000rpm. I currently have a Mercedes sensor in there which is switching and the heater is working but im looking for a genuine sensor
It didn't hesitate before I fitted the second lambda probe, it had been cured with replacement fuel injectors after a fuel cleaner had appeared to make a difference. The lambda was changed for the high idle fault and ended up causing the hesitation problems once again
It didn't hesitate before I fitted the second lambda probe, it had been cured with replacement fuel injectors after a fuel cleaner had appeared to make a difference. The lambda was changed for the high idle fault and ended up causing the hesitation problems once again
Re: [Mk2] [Generic] Hesitation at 2000rpm
I've found problems like this to be an absolute crap shoot really... Glad you sorted it in the end mind.
Yeah.. This is such a friendly place at times...
Yeah.. This is such a friendly place at times...
Re: [Mk2] [Generic] Hesitation at 2000rpm
Loque wrote:I've found problems like this to be an absolute crap shoot really... Glad you sorted it in the end mind.
Yeah.. This is such a friendly place at times...
Indeed it is all fun and games. Yours all ok still?
Re: [Mk2] [Generic] Hesitation at 2000rpm
You're a funny man.
Re: [Mk2] [Generic] Hesitation at 2000rpm
Loque wrote:You're a funny man.
You gotta be funny with all the specialist jokers or joke specialists about