Couple of Questions

[mcharman]

I would be grateful of any help with the following problems I have with my 93K Chimaera

1. The driver side door opens on its own whilst driving along for no apparent reason! (Dangerous!)

2. Whislt driving at a constant speed the ride is jerky as if engine is not giving consistant power and is more noticeable at lower speeds (bad description I know)

Any advice would be appreciated.

[wolosp]

Try this for the door problem: www.pistonheads.com/gassing/topic.asp?t=4915&f=8&h=0&hw=door+adjustment

For the lumpiness - I had a similar problem at low speeds - after cleaning the stepper motor valve, it seems ok now. The motor is located in the air plenum very near the wipers. Unplug the electrical connector and carefully remove the motor with a large spanner (careful, it's fragile), clean any carbon deposits on the valve and replace - do not over-tighten it.
Hope this helps.

[mcharman]

Thanks for this info I will try and sort the stepper motor out and see if it makes a difference.

[pendry]

I had the same problem with my door. It will be one of two problems. Either the catch return springs are not up to the job any more, stretching them a bit sometimes helps (situated under the console within the door release knob housing - lift the console from the rear there are no screws) or you need to clean and WD40 the door release mechanism / lever (situated in the side just behind the seat / door catch - lift the carpet then re glue when complete) You may find that you have to release the cable a bit by moving the little clamp on the end a bit too.

[MajorClanger]

quote:
Thanks for this info I will try and sort the stepper motor out and see if it makes a difference.

Forgive me if I'm wrong but I thought the stepper motor only comes in to play at tickover, so shouldn't be a problem if you're driving unless at extremely low speeds.

Could be all sorts of things. Have you checked the usual? Leads etc. I had a broken HT lead on a car that caused intermittent misfiring and jerkiness and was more noticeable at lower speeds (20 - 40 mph) at motorway speeds you occassionally noticed a bit of a 'lump' but not that frequently, say once every 5 minutes.

MC

[ajg]

I've got exactly the same problem at low, constant speed it's very jerky, but accelerating/decelerating and higher speeds it's fine.
The bloke I bought it off has told me that this is a characteristic of these cars due to being highly tuned?(mines a 4.0, not a HC, 56,000 miles, 1996).
I have spoken to a main dealer who said they shouldn't be lumpy at low speeds and also talked to an engineer at TVR Blackpool who said that the 4.0HC and 4.5 may be a bit lumpy at low speed but the 4.0 has a softer cam in it so should be quite smooth.
They both suggested new plugs, leads and plug extensions.
Hope we both get to the bottom of this, I will let you know what happens with mine.
Andy G

[Hut49]

Re lumpy running: Sure it's possible that it might be plugs, extensions or leads...could be other things too. For what it's worth, my experience has shown me that it's futile to start replacing things in the hope that you might by chance replace exactly that component that has failed/is failing. You can quickly burn a wad if you strike out several times and become more and more desperate. It's like gambling - someone up there knows just how often to give you a break so that you convince yourself that the odds of uninformed diagnosis are on your side - then next time you convince yourself that a speculative £150 "fix" (8 plugs, extensions and a new set of leads) is entirely reasonable. Perhaps it works but likely it won't then there's always someone around to say: well it could be this or perhaps that, and so it goes on.

My recommendation would be to track down a good diagnostic centre with tvr expertise and have them run the tests that will point to the cause of lumpy running (no they don't all do that, sir!!). You could save yourself a bunch of money and get to the objective (fulfillment of the tvr experience) quicker.

Just my two pennyworth - take it or leave it.
Hutch

[SMB]

What speed in which gear were you doing to get a lumpy ride?
Also was the car cold, at temperature, or getting hot?

[mcharman]

Thanks for the comments so far. It is lumpy at any speed but more noticeable if it is travelling at say 30-40mph in 4th gear. Car can be hot or cold makes no difference. Cleaned the stepper motor which made it idle better though. I may take advice and get TVR person to look at it. I live in Wigan NW does can anyone recommend a good place to go?

>> Edited by mcharman on Wednesday 2nd October 19:23

[mj04uk]

I've got exactly the same problem, lumpy runing in any gear at a constant speed between say 1600 to 3000 rpm. Running on Optimax, had new lambda sensors installed and had it diagnosed and all say it's ok. It's just that I'm sure it was'nt running like this when I bought it

[jamieheasman]

This is very characteristic of a dodgy cat or lambda sensors. These should be easy to diagnose on a fault code reader or even with a simple volt meter.

However, there is another more expensive cause of this problem and that is cam wear! Probably not something you could identify yourself but worth bearing in mind once you've exhausted all the 'cheaper' alternatives.

By the way the 4.0litre is bog standard Rover Disco / Range Rover and the 4.0litre HC differs by being fitted with crudely modified heads and a ridiculous high lift cam.