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Se Throttle Position Switches, Delco Inj.


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my SE has a fault that is next on the list for attention.

when coming off idle, to pull away say, the engine kinda dies a bit, then revs up, as if the tps is set wrong. i have noticed its mounting screws have been undone/done up, because i can see a screwdriver has been used on them badly at some point in the past as if someone has tried sorting this before.

hopefully i have the correct service notes supplement coming in the post, and maybe its all explained in there, but i was just wondering, is the base output at idle 1.47 volts as the freescan parameters suggest, and do you move the tps about on the screws as i have on other cars to effect an adjustment? think its output at wot is 4 volts. read that somewhere. its really tricky to drive slowly in traffic, and its p....... me off somewhat. everything else seems fine. jacking solenoid is good, all working, boost now perfect, now it gets warm enough to tell the ecu to give it max that is. ive taken some slack out of the throttle cable too, but it still tries to stall a bit, before it revs up. got free scan coming, as that has gotta be a brilliant idea anyway, but not sure if this problem will show up on it.

i am trying to get the car as good as it can be running wise, in standard set up, without going for rechipping, decatting etc, if this was sorted i think it will be quite good to drive, but the exhaust is rather tired, so need to sort that before any major mods really.

any ideas o fountains of knowledge?

ps. loving this car btw, it rocks. still trying to find Beverly Hills though. i thought my lawyer said it was down the hill? lol. must buy a dvd of that!

Edited by pitstoppete
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Hi Pete

The problem you've got with it dying as you blip the accelerator from idle is exactly the same problem mine had recently. The car is currently at Maidstone Sports Cars having this fixed and a C service.

The problem turned out to be the TPS (which, with the help of Dermot and Freescan, I'd already identified as part of the issue) and also the crankshaft sensor was apparently caked up with [email protected] so the poor ECU didn't know where the bottom end was at any given time, leading to lots of engine knocks and near detonation.

Freescan really is an invaluable tool as it immediately identified all these problems and potentially saved my engine as, had I not known about the knocks, I might have continued driving the car and destroyed it.

Hope this helps

Steve

89 SE Pacific Blue

http://lexi.mantaur.co.uk

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A freescan log file would enable me to look at your TPS and the other sensors. 

O% TPS should be 0.5Volts. 

Dermot

<{POST_SNAPBACK}>

cheers guys. freescan is in the post as we type, and hopefully its the tps. so is it just an adjustment thing, or do they just die? some other cars i have played with burn there tracks out on the tps board at and around idle, leading to these kinda symptoms. do u set them up to 0.5 volts throttles shut, or are they preset to be right. I know alot of things about other stuff, but not much about tps's! i do know my cavalier one just bolts on, and is not adjustable, but some are it seems.

car is really fine apart from that fault, as i said, no knocking etc. it does like seem to like optimax fuel, as it should, so the knock sensor seems to do its thing too. and the rev limiter seems operative in lots of gears (snigger snigger!) too.

next question is, before i get the technical supplements covering the delco inj cars, what does the speed sensor do on the o/s/r wheel. is it low speed boost related?

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The data from the VSS is used by the ECM to control the a/c and radiator fans under certain conditions (Lotus Manual EMH.2 - H), and also the boost control solenoid valve (Lotus Manual EMH.2 - T).

Simon  (94 S4)      My Esprit will be for sale in late 2017

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The data from the VSS is used by the ECM to control the a/c and radiator fans under certain conditions (Lotus Manual EMH.2 - H), and also the boost control solenoid valve (Lotus Manual EMH.2 - T).

<{POST_SNAPBACK}>

cheers for that too. emh is indeed the place i need to look for this stuff.

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Do you have the actual manual handy.

I have the original book and have adoberised it (if there is such a word) - If you need a certain chapter just drop me a line. Each chapter is about a meg.

Simon  (94 S4)      My Esprit will be for sale in late 2017

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Do you have the actual manual handy. 

I have the original book and have adoberised it (if there is such a word) - If you need a certain chapter just drop me a line.  Each chapter is about a meg.

<{POST_SNAPBACK}>

cheers simon, its the emh part especially, paul c has sent it all! :blink: but i could do with emh today if possible. [email protected]

going to take the tps off anyway, and buzz it through with a dvm to see what its doing resistance wise around the idle position, I'm suspecting its got dirty tracks where the wiper goes across the tracks, but only near idle etc. this has happened to many ford and vauxhall owners i know too. seems common.

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Er - Hotmail is bouncing the (+1 meg) emails. You'll either have to increase you're email acceptance size or provide alternative email address.

Simon  (94 S4)      My Esprit will be for sale in late 2017

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Er - Hotmail is bouncing the (+1 meg) emails.  You'll either have to increase you're email acceptance size or provide alternative email address.

<{POST_SNAPBACK}>

thanks for trying Simon, but panic over chaps. the postman's been, and i have what i need (thanks paul) in my pc as i type, and its great.

been rather busy on it again today -

cleaned the tps up, been for a spin in the fog, the cars flying anyway coz of the foggy air, but is better and smoother low down. hopefully all will be well when i get a new tps on wed. idle valve is getting a clean tomorow too. fitted a brand new burr elm dash set this afternoon, as mine obviously missed out on any wood at the factory, and got the std black plastic. its lovely. seriously lovely.

also its now got a rear chargecooler mounting too, as that was missing completely. heat shield is all polished too! and refitted with stainless steel washers/nuts etc. lovely jubbly. oil level has settled down also, now the thermostat has bled all the air out of the hoses and coolers etc.

oil temp gauge reads a absolute max of 80 deg C, which is spot on,

water temp shows about 80 when the fans cut in if you leave it ages. this reads a bit low everywhere, just like my excel does.

oil pressure now much higher/steadier after changing it to castrol rs 10/60. 5-6 bar cold, 4 bar hot driving, 2 bar idling. seems good now. did have to top it up again when the thermostat fully bled all the air out and its staying spot on the high now. got some new pedal rubbers to go on tomorrow, and a some miles to do! as u may be able to tell, I'M LOVING IT!

thanks again 4 the help with the supplements/manuals everyone :)

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thanks for trying Simon, but panic over chaps. the postman's been, and i have what i need (thanks paul) in my pc as i type, and its great.

been rather busy on it again today -

cleaned the tps up, been for a spin in the fog, the cars flying anyway coz of the foggy air, but is better and smoother low down. hopefully all will be well when i get a new tps on wed. idle valve is getting a clean tomorow too. fitted a brand new burr elm dash set this afternoon, as mine obviously missed out on any wood at the factory, and got the std black plastic. its lovely. seriously lovely.

also its now got a rear chargecooler mounting too, as that was missing completely. heat shield is all polished too! and refitted with stainless steel washers/nuts etc. lovely jubbly. oil level has settled down also, now the thermostat has bled all the air out of the hoses and coolers etc.

oil temp gauge reads a absolute max of 80 deg C, which is spot on,

water temp shows about 80 when the fans cut in if you leave it ages. this reads a bit low everywhere, just like my excel does.

oil pressure now much higher/steadier after changing it to castrol rs 10/60. 5-6 bar cold, 4 bar hot driving, 2 bar idling. seems good now. did have to top it up again when the thermostat fully bled all the air out and its staying spot on the high now. got some new pedal rubbers to go on tomorrow, and a some miles to do! as u may be able to tell, I'M LOVING IT!

thanks again 4 the help with the supplements/manuals everyone :)

<{POST_SNAPBACK}>

bit of an update:- just unscrewed the idle valve. was a bit loose, and sticking out of the manifold a by about 2mm. measured the pintle length as in the EMH manual, and it was about 23 mm. reset it back to 20mm as suggested in EMH, straightened the mounting flanges, popped it back in, o ring seating nicely now, and hey presto, a sensible cold idle straight away, not 1800, followed by it settling down to 950 ish hot, but it still nearly stalls when blipped. ok when revs are made to rise slowly, but when blipping it, it tries to die. judging by the amount of silicon sealer round the little o ring on it, someone has had trouble before. it must have been leaking in a certain amount of air all the time, and offsetting for that.

emh says the counts of the idle valve only reset once per engine run, when the speed is over 20mph at moderate acceleration. think wot i'll do is fit new tps when i get it, reset ecm, and then go for a short drive when warm, and it seems that might reset it all. any one else delved this deep into this problem?

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bit more of an update,

trying to sort the bad running of my SE:-

got me freescan, plugged it all in, dont work from under dash plug. o well. laptop on sunroof, car in garage, key in ignition. im leaning through the window, which incidentally dont exactly rush down when operated..........

started communicating with freescan, keeps dropping out, like its disconnecting.

played a whole load looking at the sensors etc. got a log file anyway of sorts. taught meself a bit of graph plotting in excel, noticed how erratic the idle and battery volts are, and with investigation, how loose the frigging alternator is!!! oops! assumed the lotus position, spread out in the boot area like, very nasty aches and pains coming on, sorted the floppy alternator, :blink: now we have a proper amount of batt volts, regulating from 13 to 14 like it should not cutting in and out around 12-12.5 ish. the lights have stopped flickering, the gauges seem to be responding better, the headlights are actually giving out white light now not yellow, so i reset the idle valve, and the blm when warm, and apart from the chuffing like a steam train exhaust manifold, its the dogs dangly bits! all sensors seem good. but it still dips the revs first, when you blip the gas quickly.

so not a bad night really.

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Glad it's all heading in the right direction...... but you're still being plagued by that effing stumble!!! :blink::D

"When I was a kid I used to pray every night for a new bicycle. Then I realised that the Lord doesn't work that way so I stole one and asked him to forgive me."

------------------------------

ribbon200.gifG-Car Owner and Proud! ribbon200.gif

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right, just come in from the garage after a 6 hour session!

new TPS on and set up. 0.49 volts at 0%. lovely.

huge 20 minute Freescan file called "coldstartnewTPS" logged. see the fans cut in and out. 92 deg C etc.....

car seems to sound better, miles smoother, idles nicer and plugs also look new and good condition.

Thought I'd dive under and try and sort the leaky exhaust manifold for sure, before i get a new system on there. someone has had the head off a while back, the manifold off too, all of the threads have been helicoiled, as I have a receipt for it, but who ever "threw" it back together, wound the studs in by hand by the feel of it, and didnt bother with half of the locking tabs. no wonder its trying to fall off.

So now, its got the studs wound to the bottom of the threads, some of them have stainless bolts inbottomed right out too, and the nuts are all tight, tabs knocked over. not an easy task on an Esprit, is it! Some of the threads are a bit nasty, but it doesnt seem to be leaking there anymore. but there is a tasty hole on the middle of the silencer!.

Oh well, out for a VERY slidy test drive in the rain, (woo hoo!) and it's still got the stutter off of idle that its always had. Shitte.

goes better though, it's nicer/easier to drive and its much better off of idle, but not fully cured

Anyone got any other ideas?

gone through all the vacuum hoses around the inlet side, and all the sensors seem to be behaving according to the Freescan instructions

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fitted a brand new burr elm dash set this afternoon, as mine obviously missed out on any wood at the factory, and got the std black plastic. its lovely. seriously lovely.

Mmmm... If you still have the Black plastic fascia, what sort of nick is it in?.

Am not a great lover of the wood in mine and it has the standard 'cracked

veneer' finish. Might be interested,if you wanna lose it...

Your idling,

While chasing my Code 26 through various components, the Throttle jack solenoid was one i messed about with and then replaced. Have you tried disconnecting it to see if the problem persists?

This could be done by disconnecting the electrical plug (after 20secs will bring on the check light as a hard fault), or by removing and plugging the vaccum line.

Am considering removing my throttle jack as with the EBPV gone it is pointless when jacking for the warmup cycle, and with my aircon busted and disconnected it will not be called on to jack the revs at aircon load either....

PS, My aircon has a Sh4gged expansion valve. This will only ever get mended if i have loads of money at the start of the summer. It appears that Lotus started with the wiper motor and aircon expansion valve - and then built a car around them :blink:

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  • 2 weeks later...
Oh well, out for a VERY slidy test drive in the rain, (woo hoo!) and it's still got the stutter off of idle that its always had. Shitte.

goes better though, it's nicer/easier to drive and its much better off of idle, but not fully cured

Anyone got any other ideas?

<{POST_SNAPBACK}>

Hi,

I recognize your problem, I've got the same thing on my 92 2.0 highwing.

I changed the TPS for an aftermarket part and things got better but noway near perfect. Thing I've noticed is that there is less hesitation when engine is cold, in other words when fuel is flowing a little richer. I have not tried freescan yet( sorry) and can therefore not verify the TPS voltage a 0% but I plan to do that in the coming weeks. I'll stay in touch..

:blink: Joakim

Edited by joakim_adolfson
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thanks for the reply, going outside now to try a new idle valve and o ring, as they are not very good.

Hi,

I reconize your problem, I've got the same thing on my 92 2.0 highwing.

I changed the TPS for an aftermarket part and things got better but noway near perfect. Thing I've noticed is that there is less hesitation when engine is cold, in other words when fuel is flowing a little richer. I have not tried freescan yet( sorry) and can therefore not verify the TPS voltage a 0% but I plan to do that in the coming weeks. I stay in touch..

:)  Joakim

<{POST_SNAPBACK}>

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oh yes, been away all across xmas/new year to sunny Malta, so no time to play broom brooms. and yes, it's still got it. I've been kinda driving round it untill i get the time to get in the back and check every single piece of vacuum hose/wiring connector/gasket sensor etc, before i start sending freescan plots to Marcus/and or Dermot, as they seem to be the wizards on that. going to clean the crank sensor too, as i have had a similar fault with my other car which got better after I got the clag off of the tip of the end of the magnetic part of the sensor.

Hi ,

I wonder if there have been any progress with the small throttle stutter??

Regards Joakim

<{POST_SNAPBACK}>

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well, a quick update. been busy fixing other bits of the car, also fully sorted the manifold that was trying to fall off, so it now has no exhaust leak. also done the ram air intake mod (cant believe the noise when i open the window my side) went out for a spin, it now sounds like a completely different car but the stumble is still there when the car is hot, and i have noticed on freescan that the icv counts go down to 20-25. this rather point towards an inlet air leak, just like my daily runaround car has got! now got to go through all the pipes and hoses/gaskets to find the possible culprit.

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and i have noticed on freescan that the icv counts go down to 20-25. this rather point towards an inlet air leak, just like my daily runaround car has got! now got to go through all the pipes and hoses/gaskets to find the possible culprit.

<{POST_SNAPBACK}>

Ok, that would be interesting since my Engine sound a little dry when idling.

I also have problems with high Lamda value which would indicate the same.

I guess I must get hold of some freescan equipment soon. Just been to lazy and think

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