89 M100 Turbo Wont run past 3000 rpm hits a brick wall

[Tuga2112]

does the save file from elanscan hold all the graphs ? it may be worth uploading it so that anyone trying to help (or just curious) can get a copy and analise.

posting screenshots only shows you the graphs ofr the few variables sleected. where using the app will allow someone else to try and correlate more factors at the same time.

my personal experience with the system was that i got the impression it was very powerfull with its dataset but ultimately my issue was the fuel pump hose being disconnected and the graphs have nothing about fuel pressure because the regulator is vacuum operated instead of electronically driven

[kevrob]

The service mode just disables most of the sensors - so it will never perform properly, in effect, it enters 'limp home' mode and won't let you rev high or engage the turbo. It errs on the side of safety by over fuelling so as not to run lean and risk a melt-down.

The revs shouldn't rise when you enter service mode - they should be at 950rpm in service mode, and if it isn't then you need to adjust the throttle bleed in service mode to get it correct at 950 (preferably measured on ES not the tacho - which can be a bit awkward as you can't get a paperclip in to set it into Service with ES plugged in..... I got round this by splicing the 2 wires into the plug and connecting a switch in the glovebox, so shorting out the 2 wires with the switch enters Service, and ES can still be used.)

Ok So I am getting somewhere in a roundabout way.. looking at another post ive adjusted the Magnetic Pick Up gap tried 20 thou at first didn't like it, now 15 thou... the problem has now switched almost to the other end of the RPM range, I can now fly along from 3500 to redline but the car stumbles now between 2000 - 3000 rpm.
This is crazy there is no information in the Lotus Workshop Manual about setting the correct gap or troubleshooting the Magnetic Pick Up which I would like to change but seems unavailable.

Whats my next move ? 10 thou gap ? New sensor ..

[KenS]

Is changing that gap in effect changing the timing? i.e. if the gap is made smaller the switch occurs earlier, if the gap is made larger the switch occurs later? Would be interesting if a stobe could confirm that.

[kevrob]

Is changing that gap in effect changing the timing? i.e. if the gap is made smaller the switch occurs earlier, if the gap is made larger the switch occurs later? Would be interesting if a stobe could confirm that.

I dont think it should effect the timing as its purely a speed reference for the ECM. Im in the process of checking the wiring to make sure ive a good ground and good voltage signal but I will probably have to buy a complete new CAS assembly unless its possible to use an aftermarket race Magnetic Pickup. From what I can glean gaps go from 0.007 to 0.070 thou so quite a range hopefully i can find out first what the gap should be or if the sensor is basically bad.

[dapinky]

The Hall effect sensor - A100E0102S - is still available from lots of places, but is cheapest at South West Lotus.

Unless there is a mechanical problem with the CAS there should be no necessity to replace the whole thing.

[HJ2]

Correct!
But the are mechanically failing every now and then.

[Tuga2112]

i thought the "common" mechanical failing there was the excessive play. usually caused by the little pinhole wearing. and the practical solution to it was the enlarge the hole and put a new pin throught it ?

[dapinky]

i thought the "common" mechanical failing there was the excessive play. usually caused by the little pinhole wearing. and the practical solution to it was the enlarge the hole and put a new pin throught it ?

I suppose that as they get older there is more opportunity for mechanical wear - although the most commonly reported fault is as you describe, the bearing can wear (simple replacement part, as any other bearing unit), and also the 'tooth' bit that engages in the cam could wear - but all of these are fixable without replacing the whole unit (except a replacement unit will at least be a point where you are starting with everything "good" on it....

.... assuming you can find a new CAS unit, I know they are listed under part number A100E6020H, but I don't know if they are actually in stock (they went obsolete for a while, but may now be back again), I assume they are, as they are listed as 'factory order' on the Deroure website (Bell & Colvill) at £380 + VAT

[Simon_P]

What's the part number of the MAP sensor that you have? There are similar ones with different pressure ranges.
Which injectors did you buy and are they 2 Ohms.

[kevrob]

The Hall effect sensor - A100E0102S - is still available from lots of places, but is cheapest at South West Lotus.

Unless there is a mechanical problem with the CAS there should be no necessity to replace the whole thing.

I dont need the Cam Angle Sensor I need the Magnetic Pickup or Speed Ref sensor...

[Chas54]

Could do with seeing an elancan data set from cold start to fans cutting in and out , stood still on your driveway .
On your original scan i did notice that your manifold vacuum pressure was too high . It should be bellow 40mb idling. But your IAC did show at the latest point on the trace ,that it had pulled in to count 9. It would do that if you had excess air getting in somewhere. But it is best viewed at working temperature.
Have you tested the fuel pressure regulator valve doesnt have a leak on the vacuum side .

The random flickering and wandering of your strobe light is something i see also . I have put it down to the HT sensor picking up some induced voltage from one of the other HT leads .

charlie

[simonbuk]

What was the outcome ?