High Idle speed Suggestions
11-06-2010, 01:11 PM
#31
Instructor
Thread Starter
Malcolm, yes can verify the throttle plate went back in the same way, just rechecked again.
The strange thing is the high idle is exactly the same speed prior to intake refresh. It makes me thik its something else causing the issue, but cant think what!
Forgot to mention, the auto shift is super smooth, disconnecting vacuum to auto makes a big differnce to shift smoothness, but no differece to idle speed!
The strange thing is the high idle is exactly the same speed prior to intake refresh. It makes me thik its something else causing the issue, but cant think what!
Forgot to mention, the auto shift is super smooth, disconnecting vacuum to auto makes a big differnce to shift smoothness, but no differece to idle speed!
11-06-2010, 01:20 PM
#32
Rennlist Member
What is the fuel pressure?
11-06-2010, 01:29 PM
#33
Instructor
Thread Starter
Will keep a look out for an LH ECU, I do not know anyone in UK to borrow LH to check it out. JDS checked it out earlier this week, but you may well be right. I am confused because prior to intake refresh I knew the TPS was not working, it was completely open circuit under all conditions. With the new TPS there was no difference at all to idle speed. ( I am checking TPS at both LH and EZK ). Its as if the TPS makes no difference and from what I see now there seems no difference to idle when I disconnect vacuum lines either.
11-06-2010, 02:59 PM
#35
Rennlist Member
Hi Steve,
Well, not the desired result, but probably not entirely unexpected. Malcolm has a good suggestion about checking your fuel pressure. I still wonder if the PO adjusted the throttle plate stop.....
Glad to hear the new MAF behaved as expected. I am pretty confident your LH ECU is good.
Well, not the desired result, but probably not entirely unexpected. Malcolm has a good suggestion about checking your fuel pressure. I still wonder if the PO adjusted the throttle plate stop.....
Glad to hear the new MAF behaved as expected. I am pretty confident your LH ECU is good.
11-06-2010, 03:03 PM
#36
Rennlist Member
There's a test port on the end of your driver's side fuel rail. there's a big nut and a ball bearing behind it to seal the rail. Make sure no pressure in system before undoing. I can't rememner the thread type used.
Might be simpler to buy the fuel gauge kit from Roger Tyson.
Might be simpler to buy the fuel gauge kit from Roger Tyson.
11-06-2010, 03:07 PM
#37
Rennlist Member
I'm thinking that air/fuel mix is too lean so unless we find an air leak its perhaps not receiving enough fuel but to be honest I'm grasping.
Fuel pressure is normally checked on the end of the RH (when seated in the car) fuel rail with a fuel pressure guage.
With all the throttle body vac lines plugged that essentially omits all the components downstream of introducing air and given your pressure test indicates good seal then the issue seems to be outside the intake system.
Is the eprom in the LH OEM?
Fuel pressure is normally checked on the end of the RH (when seated in the car) fuel rail with a fuel pressure guage.
With all the throttle body vac lines plugged that essentially omits all the components downstream of introducing air and given your pressure test indicates good seal then the issue seems to be outside the intake system.
Is the eprom in the LH OEM?
11-06-2010, 03:13 PM
#38
Instructor
Thread Starter
John, thanks, car responds a lot better now. feels completely different. Idle speed is not different at all , still hunting around 1100rpm ( as we thought it would). Its seems that nothing I have done changes the original issue, ie the high idle. The only thing I seem to have achieved is better throttle response(courtesy jds) and smoother auto shift (vacuum 21in hg?). s the fuel pressure relevant to the idle? Is there a simple way to check fuel pressure? Orderig parts from Roger will take 4 weeks due to postage.
11-06-2010, 03:14 PM
#39
Rennlist Member
Now there's a great thought.
If the stop is holding the t.plate open then the TPS, even if set properly, wont compensate and I pressume neither will the LH.
But surely pressurizing the system would find that unless the incoming pressure through the MAF is forcing the t.plate closed.
If the stop is holding the t.plate open then the TPS, even if set properly, wont compensate and I pressume neither will the LH.
But surely pressurizing the system would find that unless the incoming pressure through the MAF is forcing the t.plate closed.
11-06-2010, 03:24 PM
#40
Instructor
Thread Starter
Malcolm , I think eprom in lh is standard, perhapd john can verify? When I took intake off I think it was for the first time ever. Dont think PO have ever been there. All hoses were hard, all looked original. Thottle stop had yellow paint on it which looked like factory original. I changed everything under intake and triple (! literlally ) checked connections during reassembly.
During intake refresh i changed spark plugs. old plugs ( dont kow 'how old') looked light brown, no evidence of soot / black etc. Like biscuit colour? I had recent government annual test for car, CO was 0% (limit 3.5%)
During intake refresh i changed spark plugs. old plugs ( dont kow 'how old') looked light brown, no evidence of soot / black etc. Like biscuit colour? I had recent government annual test for car, CO was 0% (limit 3.5%)
11-06-2010, 03:38 PM
#41
Rennlist Member
The LH had never been opened, so we can assume software is stock. I didn't need to open it to test it fully. What happens to idle speed when you put the car in Drive from N ? What happens to idle speed when you switch aircon on ?
Did you get your smoke matches ?
Malcolm, Steve's car is unusal for a uk car in that it has cats and O2 loop, and emissions look fine. This is a most strange fault.
Did you get your smoke matches ?
Malcolm, Steve's car is unusal for a uk car in that it has cats and O2 loop, and emissions look fine. This is a most strange fault.
11-06-2010, 03:42 PM
#42
Instructor
Thread Starter
Malcolm, just reread your last post. I only tried unplugging vac lines serially and noting any difference (none). Will try plugging all throttle body vac lines in morning and report back.
Not very scientific, but the t plate looks 'closed' when checked. Have resisted fiddling /adjusting with things like this, until I am more confident of cause. I can see yellow paint straddling thread body of stop which looks like factory paint to me?
Not very scientific, but the t plate looks 'closed' when checked. Have resisted fiddling /adjusting with things like this, until I am more confident of cause. I can see yellow paint straddling thread body of stop which looks like factory paint to me?
11-06-2010, 03:49 PM
#43
Instructor
Thread Starter
John, Idle in park is solid 1100rpm, gently hunting. This has been constant from the time I bought the car 18 months ago. In drive idle is approx 800-900rpm. Also at cold the idle is 800-900rpm. Only after engine is warm it moves to 1100rpm. Aircon makes no difference, neither does disconnecting 02 sensor.
Yes tried smoke matches today. ~Tried 20 matches when engine running ( burnt fingers twice~) no evidence of draft anywhere around intake
Yes tried smoke matches today. ~Tried 20 matches when engine running ( burnt fingers twice~) no evidence of draft anywhere around intake
11-06-2010, 05:01 PM
#45
Rennlist Member
The LH had never been opened, so we can assume software is stock. I didn't need to open it to test it fully. What happens to idle speed when you put the car in Drive from N ? What happens to idle speed when you switch aircon on ?
Did you get your smoke matches ?
Malcolm, Steve's car is unusal for a uk car in that it has cats and O2 loop, and emissions look fine. This is a most strange fault.
Did you get your smoke matches ?
Malcolm, Steve's car is unusal for a uk car in that it has cats and O2 loop, and emissions look fine. This is a most strange fault.