TVR Chimaera 400 Idling Issue

[JAIrvine]

Hi everyone,

I own a 1999 TVR Chimaera, but I'm in Canada so garages who know about TVR's are hard to find...

My TVR runs pretty well and is a pleasure to drive. However, I noticed as the summer ended, it has an idling problem - when stopped at traffic lights / stop signs / traffic etc., the car struggles to idle stably. The revs drop right down, and if I don't feather the throttle in neutral, it's likely the car will cut out completely. Furthermore, the car has the classic 'hot start' problem, so if it cuts out after running for 15 mins plus, it won't re-start until it cools down, leaving me stuck in the middle of the road if the car cuts out.

Long story short... (too late?) wondering if anyone else has had this problem, and if there are any solutions anyone has found / can recommend?

Thank you!!!

[The Three D Mucketeer]

I had similar problems and it turned out to be the Lambda sensors ... Be worth getting an ECU cable and install Rover Gauge software...
Many threads on PH re Rover Gauge but here is one for example :-

https://www.pistonheads.com/gassing/topic.asp?h=0&...

PS Getting hold of Original NGK sensors was difficult and many Chinese copies are about

[Belle427]

First thing to do is remove and clean the stepper motor properly.

[Zeb74]

You should start with by cleaning the stepper, it tends to get dirty and this affects the idle speed.
For the hot start, you need to check your main ground cable, when it starts to corrode, its impedance increases and if you add heat, it's too resistive.

[BritishTvr450]

As above
Also hot start problems can be associated with the immobiliser.

The next time it happens turn the car off and on again, if you fail to hear the fuel pump priming at the left rear of the car that’s a sure sign the immobiliser is where the fault lies.
Usually leaving it to cool down for 1/2 hr will be enough for it to re start again.

You can bypass the immobiliser which will eradicate the problem.
The alarm will still work so you still have some security with the car.

[FunkyGibbon]

When I had an idling problem it was the air intake pipe to the Air Flow Meter had come adrift. It was an easy fix - so worth a look,

[aguc]

The hot start issue is a common failing
Had same problem with 99 500....way back in 2003.....fitted a fix kit by Modwise never been a problem since. Involves extra relay fitment near the battery approx 1hr to install. They also do half speed cooling fan mod with thermostat adjustment which works well...these engines do suffer in traffic on Hot days. Modwise used to advertise in the TVR club mag ....hope there still about as fix is still working 22yrs later.

[spikep]

Hot start issue replacement wiring diagram. Taken from another thread on here.

[blaze_away]

Good advice about cleaning the stepper motor. So do that and then set the "base idle"

To set base idle
1. Get car fully up to temperature
2. Allow the engine to idle
3. Clamp the hose that supplies air to the stepper motor (about 1 inch hose that goes under throttle butterfly to rear of plenum)
4. Adjust base idle screw to get rpm to 700 ish. It's the Allen headed screw on top of plenum near butterfly.

Note if the engine won't idle when you clamp the hose then unscrew the adjuster until it can.

I would also strongly encourage you to get RoverGauge and a cable so you can look at what's going on with the ECU. I can help you with understanding/analysing the data. Have done this remotely for dozens and dozens of RV8 cars.

[JAIrvine]

Thank you ALL for so much helpful and incredible advice. I'll be saving everything for spring, when I can get the car safely back out again, and start looking at all the suggestions to see what works / helps!

Appreciate everyone who uses this forum - life would be a lot more difficult without all of your valuable knowledge!