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pitstoppete

A nice idle?, SE

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right. having a nightmare.

long weekends work - just put all the manifold/plenum/fuel bits and pieces back together on my SE. sorted lots of potential leaks/bad gaskets/tired hoses etc.

all the breathers and hoses/one way valves are ok, triple checked all that. filled up the coolant. lovely, no leaks.

plugged me laptop in, fired up freescan. turned the key, off we go, lovely.

baro is .88, map is .4-.45 ish as it should.

icv is 170 ign on

rev it up warming up from cold and it dont stumble,

rev it hot and the icv goes to maybe 7 or 8, then trickles down to 0 again

everything seems ok, apart from the off idle stumble/stutter is still there when warm, but only sometimes, its happening when freescan shows it idling on zero counts of the idle valve. this is wot its always done, and now its back.

it seems to me its fully idling through another source somewhere.

i havent driven it yet, as the tailgate is wedged up high, so i could get in the back easier. want to drive it to see what the idle valve does over 20 mph, as freescan manual says it should sort itself out (but it never did b4)

aint got me tasty chargecooler pump through yet, so rigged up a worn out bosch one i have been trying. MAT temp once it was all bled is good to go. thats a different thing than the idle rubbish.

anyone got any bright ideas? are we sure this crapness is not inbuilt into the ecu. perhaps the ecu is bolloxed. perhaps the lambda aint as good as it could be(seems good on freescan), would that matter?

when its idling its unbelievably smooth as silk, just when i blip or increase the revs, it dies then revs up. on the road this causes a bit of stalling or opposite, loads to many revs on pulling away. eek.

Dermot, got a file for u 4 tomorow, its on my laptop, so i'll send it from work.

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OK,

IAC should settle to arround 40 when idling and warm.  It is a good test for air leaks or a sticking IAC valve.

D.

<{POST_SNAPBACK}>

thought the charcoal canister thing with the pipe coming out of it may be faulty, as there is vaccum from the back of the inlet manifold going to it. (thought the solenoid valve may be stuck open or something) pulled the one way valve off and plugged it, removing it from the system, not change. MAP is definitely only 0.36-38 at the idle speed when baro is 0.810 (std). thought it should be higher. perhaps all this is caused by a bad map sensor. shall i trace the little hose back and see if theres a dodgy little pipe/right angled connector or something. aint looked there yet?

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also noticed that the BLM is going to rich all the time when the icv is zero. occasionally when its idling throught the icv, and i rest the blm, the fuel integrator is going slightly lean, 127-126 etc.

and below 100 revs, i can definitley hear and feel the ecu cutting a cylinder to control idle. it sounds like someone is pulling off an ht lead for maybe 2 seconds, the idle struggles to get it back up, then it cuts back in again.

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also noticed that the BLM is going to rich all the time when the icv is zero. occasionally when its idling throught the icv, and i rest the blm, the fuel integrator is going slightly lean, 127-126 etc.

and below 100 revs, i can definitley hear and feel the ecu cutting a cylinder to control idle. it sounds like someone is pulling off an ht lead for maybe 2 seconds, the idle struggles to get it back up, then it cuts back in again.

<{POST_SNAPBACK}>

after reading EMH 3-5 and 6, i am favouring a full test of me MAP sensor. it could be tired, but not bad enough to show a code.

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SE update. 40-50 hours work later.......

WOO HOO.

full chargecooled service has resumed.

with an awful lot of asking Dermot (cheers Prof.), and a little bit of common sense and reading the manual:-

sorted the strange idle stumble, (apart from the below 1000 revs thing they do, cutting out cylinders)

sorted the lack of any chargecooling whatsoever (what a crappy system it was)

while it was apart with inlet manifold off, and I was fitting the chargecooler blank plug, managed to fit me new leads from the legendary Mr Garry Kemp

sorted the manifold leaks, split gasket, bent M8 studs, dodgy t-piece and perished breather hoses

sorted the one way valve to the charcoal canister which was in backwards, so never emptied the liquids

sorted the Idle valve fault which was the main (supposed to be tamperproof)

screw on the throttle bodies that some one had wound in to get more idle at some point previously.

everything under the back looks nearly new again, as its all been apart! and,

sorted a huge grin on my chops when i went down the bypass.

cheers again for any advice given and big thanks again to Dermot for putting up with me e-mailing him everyday with log files. I'll still send you a final one if I may, when its re-leant the settings fully.

at least I know a shed load more about how the sensors and stuff works now. Ive had most of them in my hand sorting it all out.

and yeah, I need a back massage now :)

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Well done,  glad I could help.

D.

<{POST_SNAPBACK}>

now for a chip that make it idle above 987 rpm, so the cylinder cutting out stumble thing goes away forever then.

Hmmmmm, which chip for me! its gonna be no.5 i think. why mess about eh!

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Hi,

fantastic, you solved it, I just brought out my car from the garage and havn't been able to do anything with it yet. What troubles me is that you do not seem to have any miracule cure... :) It just seem your car was put togeheter very badly.

I guess it could be the same with my Esprit since It had been in for an head overhaul just before I bought it. I also have problems with high lambda values which could point in this direction. The problem is that I havn't got myself a freescan equipment yet, I guess it's time for that..

:P

joakim

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Hi,

fantastic, you solved it, I just brought out my car from the garage and havn't been able to do anything with it yet. What troubles me is that you do not seem to have any miracule cure... :)  It just seem your car was put togeheter very badly.

I guess it could be the same with my Esprit since It had been in for an head overhaul just before I bought it. I also have problems with high lambda values which could point in this direction. The problem is that I havn't got myself a freescan equipment yet, I guess it's time for that..

:P

joakim

<{POST_SNAPBACK}>

get your self the freescan software/cable. apart from it being seriously cool with a laptop on the glass roof of the car, (my neighbours are in there lounge on there playstation, I'm down the garage playing with the real thing!) car sitting in the garage playing with the engine, seeing whats doing what, watching the sensors warm up, theres the amount of times ive nearly crashed going down the bypass on a test drive, watching the dials and parameters changing on the laptop on the passenger seat. but u really need it so u can send a logfile to someone who knows what there doing, to diagnose the problems. mine is still not perfect by a long way. I think the Lambda on mine is tired, and the std chip is just rubbish. cutting out a pair of cylinders at idle maybe ok for a yank V8 engine, but our 4 cylinder ones dont like it. need a later spec base chip really on an SE, S4S profile is a good start it seems. got a coolant leak too, and its the hose clip on the inlet manifold from the thermostat, the only one i forgot to do up, and its probably the only clip u cant actually see. o well. thats a job for tomorrow night when its cooled down. a lot

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another update!

come in from garage, got the hump now with it. Need a break(a few beers i think)

not solved yet. At least it goes a lot better now with some chargecooling! Its only using the knock control a bit now, not lots......

Disconnected the Wastegate frequency vavle to check mechanical boost. seems fine. max it goes to is 0.65, maybe 0.7 at a push

Stumble problem - seems the Manifold pressure (suck) at cold idle is good, and it doesnt have the stumble when cold/cool. When its hot and i raise the revs a bit, it still stumbles. You can see on the freescan data that mostly the idle valve is at 20-30 at hot idle, apart from sometimes its at zero and still idling through somewhere else beautifully. just it stumbles badly when i pull away still. With a new MAP sensor, the data still reads the same 0.45 cold idle, 0.3 hot (another

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Hi Pete, have you tried to change the Lamda yet??

I wonder because I'm experiencing no problems when running cold( fairly rich, you also describe this effect) but still having the stutter when warm.

// joakim

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seems lambda is ok I have been told. on freescan, it shows the correct voltage swing as it should.

going to double check the throttle butterflies and spindles for alignment next. someone has been in there before (i can see screwdriver marks on the little butterfly screws) and maybe they are not seating right, twisted or butterflies are loose etc.

the new MAP sensor has definitely made the car smoother to drive, but hasnt actually cured the off idle thing.

but now with the chargecooler nearly fully working, it dont arf go! had a bit of a moment up my local dual carriageway with a Yamaha R1 bike, (reg no:- R1 ###, well done chap by the way if your reading this. Hope you had dark coloured underwear on when the back end went all wobbly!) up to about 120-130 we were kinda neck and neck, then the sunday drivers got in the way, thankfully for my licence. then Mr Crotch Rocket Yamaha went through the slower two lanes of 70 mph traffic at least a ton, as he had a bit of trouble slowing it down.

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up to about 120-130 we were kinda neck and neck...

Note:

As pete has failed to add a disclaimer to such a speed boast on a public forum,

I feel i should make it clear that the 120-130 mentioned was obviously KPH,

horse hands or some other bizzare method of measurment....

PS

Remember playing tag at 140 bananas recently Pete? :)

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Note:

As pete has failed to add a disclaimer to such a speed boast on a public forum,

I feel i should make it clear that the 120-130 mentioned was obviously KPH,

horse hands or some other bizzare method of measurment....

PS

Remember playing tag at 140 bananas recently Pete?  :)

<{POST_SNAPBACK}>

no no no, the silver car was just a figment of your imagination at that speed. i was only doin 70 officer...

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