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rough idle?


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Hi again guys :) things are coming along ok in the world of my esprit sorted most of the little niggles but I still have one that I have not figured out, the rough idle feels like its missing a beat somewhere but its not constant and alot better when its warm. I did run a freescan log of the idle not driving it at the moment due to not having a gearbox mount (its being welded as I type :santa: ) anyway I have attached the log can anyone tell me if there is anything there that might help all advise is allways appreciated thanks jimi :)

esprit_log.cvs.csv

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Will not help you right now but there is a freescan event coming up on the 31 May, near Harlow essex. It is a teach in, learn how to read freescan output etc.

Come along, let me know if you decide.

Sure others will help in the mean time.

Dave

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88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. 

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  • 4 weeks later...

The idle on my esprit has always been lumpy but does settle down once its warmed up as described. I havent checked your Freescan Log but basically from what I've read over the years it seems to be a common issue. However, I've been looking into replacing the stock primary injector with modern versions and one of the benefits reported after this change appears to be a significant improvement in the cars idle. I see that R&B have matched Injectors listed for our car for about

Edited by CarlC
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Hi All,

About the Esprit 4-Cyl. turbo's idle abitilies in general ...

I've seen a few that are idleing horrible ... and (like most of them) the idle is OK, however somewhat lumpy ...

BUT, its not part of the design to be lumpy ... the Esprit 4-Cyl. turbo engine is able to idle very smooth end even, like a purring cat ... believe me !

The problem why some idle more or less horrible lies in the following parts:

- spark plugs (if they are not too good idle will be afftected)

- HT-leads (renewing the HT-leads can make your idle significantly better)

- primary injectors (most of the bad idle comes from uneven spray pattern of the old Rochester injectors ... have them tested and/or cleaned or just put in better ones like RC or Bosch and you will see how fine this machine is able to idle !)

Cheers

Marcus

Marcus

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Marcus

did all that (plus your #6 chip, IAC, exhaust valve and idle boost hardware removal) and it still hunts and lumps

compared to a Honda anyway

but it never lacks in power or smooth accelleration

chris

90SE

just because I don't CARE doesn't mean I don't UNDERDSTAND

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Chris,

hmmmmmmm .... must be chip #6 then .... just kidding.

Have you ever checked the ignition module ?

Does it idle at 1013 rpm (like it is supposed to do with chip #6) ?

Another point could be a slightly odd O2-sensor !

What about fuel quality ?

Another point ... a minor parasitic air leak in the manifold (this is very likely due to a leaking vacuum/pressure line -> have a look at the hoses/pises and the rubber elbows) is also very disturbing regarding the idle ...

Believe me, if everything is 100% fine it will idle very very well ... ok compared to a Honda or Toyota its something different :cry:

Cheers

Marcus

Marcus

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The idle on my esprit has always been lumpy but does settle down once its warmed up as described. I havent checked your Freescan Log but basically from what I've read over the years it seems to be a common issue. However, I've been looking into replacing the stock primary injector with modern versions and one of the benefits reported after this change appears to be a significant improvement in the cars idle. I see that R&B have matched Injectors listed for our car for about

- Nulla tenaci invia est via -

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I suppose R&B have RC injectors ; I did install new primaries & secondaries (RC's), and result is that the engine runs less 'raw', it's indeed like a purring cat now ; idling is around 2000 rpm when engine is cold, and settles down around 1013 like Marcus says when engine is a bit warmed up (from around 40 degrees I think)

Hans,

We also do carry RC injectors ! ... :cry::(

Cheers

Marcus

Marcus

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hey Marcus

thanks for the reply

I'm not very concerned about the non-honda idle :cry:

i did replace all the lines with silicone with no effect, but tiny vac leak was my guess as well

I have a mech boost gauge with vac on it and it is realitively stable, but that doesn't mean anything

maybe its related to the high idle (another topic on the forum) that some of us intermitantly experience

one day I will rebuild the engine and worry about it if it persists

chris

90SE

just because I don't CARE doesn't mean I don't UNDERDSTAND

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  • 1 year later...

Hi, Try again, message didn't appear for some reason. Right I have a high idle issue (well mate has). He has a S4 1994 year. Good car. On initial start up it revs high, which is normal, then it settles down okay. Then when the car has been on a run and all up to temperature it idles high, at 20 on the rev counter. Is it a sensor that needs replacing? Any help would be appreciated, thanks

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Have you reset the IACV?

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. 

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Hi what's the IACV? Nope quick jab on the throttle changes nothing. I had a word with Miles Wilkins. He said it was some electrical black box or something that's now not available, typical. That would need changing... Oh and lots of swear words Lotus this Lotus that etc, that I can't mention here. Good old Miles....

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IACV = Idle Air Control valve

AFAIK nothing is obsolete for the Delco ecm system (other than possibly the Memcal), you may not get it from Lotus but it is available. I would not assume that there's a 'black box' that needs replacing either. If the idle is being controlled properly initially then that would suggest that something is changing due to temperature and that's the issue. Have you put Espritmon or Freescan onto the car to see what's happening?

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  • 3 months later...

Does a quick blip of the throttle bring it back down?

Derek, please, why ask you if the quick blip of throttle bring down the idle? In my 1990 SE, I dont' have EBPV, but I have the jack-throttle; and yes, the initial very high idle (2600rpm at starting time) back down to 1300 with two quick blips. Is this the reason?

Feijucho.

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... the Esprit 4-Cyl. turbo engine is able to idle very smooth end even, like a purring cat ... believe me !

Cheers

Marcus

I believe you.

I'm not familiar with Freescan but I imagine it has the same abilities as the OEM Tech 1 scanner which I bought a year ago. I found my car's throttle plate had been tampered with as well as the TPS. Consequently the IAC was fighting a losing battle to control a smooth idle. It was like this when I bought it some 10 years ago.

After adjusting those and once warm it idles smoothly around 985rpm. The IAC count is within it's parameters which is basically set by adjusting the throttle plate stop. All the other sensors are also within spec eg O2 volts, fuel integrator etc etc. The car pulls smoothly from under 2000rpm, there's no discernible 3k stumble, is easy to drive in slow traffic but still has strong performance up high. It has the standard S4 chip.

So before any changing of parts I'd recommend a tune up with Freescan, Esprimon or Tech 1. The results can be very rewarding.

DanR

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Dany, my SE 1990MY with electric chargecooler pump and the S4 chip run like yours, the idle is very smooth and pulls from 2000 rpm to 6000 lineary! (Only the problem derivative from EBPV, but my idea is pull-off the jacking throtle as soon as I can: In Spain we have not very cold days!). Marcus had all the reason two years ago.

Feijucho.

Edited by Feijucho
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