new owner and a what's that button question

[Smokey Boyer]

Just a quick 'hello' post.

Just got a Chimaera 500 (converted at some point from a 400) which is in need of a little TLC. I had an S3 previously.



The photo is from the advert - the dangly air freshener was the first thing to be removed

Brief details - 5 Litre engine conversion running Megasquirt ECU coil packs and no airmass sensor (reportedly giving 310BHP, gearbox and diff rebuilt, uprated clutch, GazGold suspension, SportMotive double anti roll bar, 285mm front discs with cosworth 4 pot callipers, electric PAS, outriggers replaced, Lupo HID lights, Starfire blue paint with navy/magnolia interior.

It hardly needs saying but this is so much quicker than the S. Really happy with it so far, but only had it since Saturday.

There was rather limited history with the car, but given that it has had more owners than most TVRs and has been used on the TVR CC Speed Championship, I figure somebody on the PH forums might be able to fill in some of the cars history. The registration is L474 WYJ, but a previous plate on the car was L400 LTR some years ago. I have found photos of the car online being used in the Speed Championship in 2012.

I am still trying to compile the list of things that need attention, but as a start the engine could do with fresh oil and I suspect plugs, the wheels need a refurb or replacing, new tyres, new carpets, rear hood and panel need re-covering. The engine bay needs a good tidy up to remove some of the old wiring loom left behind, I assume when the Megasquirt was installed, as does the tangle of wires under the steering column. I would like to change the Y Piece to a Clive Ford/ACT style decatted version, and perhaps also look at changing the plenum and intake trumpets. It would also be good to get it to a specialist who can check and tune the megasquirt ECU to ensure it is running as good as it can be. All in good time as funds a little low currently having just purchased the car.

I have one question for now. What is this red push button for (with LED) on the passenger side wing of the engine bay? The LED flashes red when the car is started, and if the button is pressed and held changes to solid red. The wires disappear in to the wiring loom, and until I have time and motivation to undo one of the few tidy bits of wiring I would like to see if anyone knows what it is for. The car has a Scorpion alarm and HID lights, which I mention in case it is something to do with the alarm or lights.

[Smokey Boyer]

I had a quick look and cannot see anything obvious that would push the button when the bonnet is closed, or even any sign of anything that has fallen off that would have done this.

I thought about the ECU thing. Perhaps someone who know about Megasquirt might be able to suggest what it is, or even the process of making use of said button.

[Smokey Boyer]

Thanks for the input so far.

When the car starts, the light flashes for a few seconds then goes solid red

I am sure the other day the light carried on flashing until I had pressed and held the button for about 5 seconds.

I have pressed once, pressed twice, pressed and held, etc and as far as I can tell nothing has changed. Looks like I will be undoing the wiring loom tape to see where the wires go.

[Smokey Boyer]

The chap I brought the car from has no idea what it does either. Just working my way through the paperwork that came with the car to try and make sense of what has been done to the car over the years. Makes for interesting reading, but nothing to suggest what the little red button does. I might have to try and contact the owner from around 2011 when the engine was rebuilt and the MegaSquirt system was installed.

[Smokey Boyer]

One of the last bits of paper I found which I had not seen when going through the paperwork before I purchased the car gave a little more insight to the engine work and spec of the car, although not an actual invoice. Some of this I knew about from the advert and the chap selling the car, some I did not know about. Putting it all together;



5 Litre fully rebuilt at approximately 71000 miles in 2011 (ish)
16 row oil cooler
V8 Developments gas flowed/ported cylinder heads, with matched inlet manifold and plenum
Megasquirt MS2 and coilpacks
Inline air filter and large air intake induction
Typhoon cam
Heavy duty clutch fitted at approx 71000 miles
Pre Cats removed
Recon/rebuilt Gearbox and Diff
Baffled Sump


So I will get in touch with V8 Developments and Shaun to see if they can offer any suggestion as to what the button might be.

[Smokey Boyer]

Quick replay from Shaun last night and his suggestion is 'wideband lambda calibration button'.

[Smokey Boyer]

Yes it is on my list of things to do. Any recommendations for one near Leicester with staff that understand TVRs and MegaSquirt. Shaun from MS2 said he could do an on road remap.

[Smokey Boyer]

do I assume 'free air' means take the sensor out of the exhaust manifold?

[Smokey Boyer]

The button is a calibration button for the Innovate LC1 based Lambda sensor. Unfortunately the button was defective and needed to be replaced to get the sensor calibrated.

I visited Shaun at the weekend to get the car re-mapped. A top bloke who appears to know his stuff, and has been very helpful.