350i running rough when warm

[Yatesy350i]

Hi All

Not been on for a while as the TVR hasn't seen much use due to building work taking all my time at home. Last time I took her for a blast I noticed that once warm there was the odd short spell of rough running. Similar to running out of fuel for a split second then ok again.

I had her out yesterday and she started first turn as always. Ran great until the gauge hit 85 degrees or above then back to the intermittent rough running. By the time I got home it was noticeably rough!

I've been reading all the post I can find. Most seem to indicate it may be an engine temp sensor? Where is this one located please?

I've also ordered a set of plugs, leads etc just to make sure. Never missed a beat in the 2 1/2 years I've had her so far.

Cheers Karl.

[mrzigazaga]

Hi Karl...The CTS..Coolant temperature sensor is the inner of the two senders on the N/S front next to the dizzy...The large nut (24mm) is the Thermotime switch and the inner (19mm) is the Temperature sensor...First of all check that the pins inside the female connector are visible flush with the connector..If okay then carefully pull back the rubber boot that covers the back of it, You might need to gently prise one piece with a screwdriver to get it over the lip of the rear of the connector.

I found this on mine...Although my "Mis-fire" was not temperature related it was electrically temperature related...Strange but true.

Here were my CTS wires..Years of being twisted and the heat from the engine causing the casing to become brittle and fall off!..

This was causing a serious over-fuelling but she would start on the button every time...Although as i now know starting on the button is a sign of something wrong...Another strange but true...

Either test the one in sitchu which should read around 1.9 on the resistance ..I think...Sorry I'm still trying to get my head round electrickery...

What i have learnt is that there are a few different types of "Mis-fire" that all could be caused by a number of things but there does seem to be other signs...Like..When it gets hot it starts to "Mis-fire"...Could be the ignition amp...Could be the coil....Could be as i found out the coil lead which due to it needing to be longer than the supplied one doesn't get changed as often as the rest...

Some people say that their car wont run with the CTS dis-connected but mine did..I had a reading of zilch when i tested mine in sitchu so bought a new one which didn't do anything...Then i checked the plug... Un-plugged it and the car is a pig to start but goes like a rocket when warmed up....The bad starting is a good thing...MOTL.

Now the new CTS is fitted she starts like a pig but goes like stink...Dont forget to dis-connect the battery once the new sender if needed is fitted and leave for an hour at least or overnight.

If its randomly cutting out then check the connection plug on the ECU as it can be home but still be a mm out which believe it or not will cause the car to stall and stink of fuel....I have two large cable ties around mine.

The danger is that everything will get replaced but the bugger will still be there..Being systematic is key here...

[Yatesy350i]

Thanks Mark

I'll have a look over the weekend. I need to get her sorted to attend her 3rd Fest. But sadly just the Saturday daytime this year.

You might be onto something about the coil lead as I noticed it's a different colour to the other eight!

Many thanks Karl.

[KKson]

I had exactly the same earlier in the year and turned out it was the coil. Ran fine for 3 to 4 miles then when it warmed up there was a random misfire. Checked all sorts of things but eventually replaced the coil and all has been well ever since.

[Yatesy350i]

KKson said:

I had exactly the same earlier in the year and turned out it was the coil. Ran fine for 3 to 4 miles then when it warmed up there was a random misfire. Checked all sorts of things but eventually replaced the coil and all has been well ever since.

Thanks Keith

Any chance you have a link to were you got the correct coil?

ATB Karl.

[KKson]

Karl, got mine off flea, its a Lucas DLB198. There's a new one up at only £6 at the moment:

http://www.ebay.co.uk/itm/DLB-198-Lucas-coil-/2013...

Got mine from ANG. Great services but they've stopped stocking the Lucas unit and now stock the following, which also gives you the part numbers for other alternatives:

http://www.ebay.co.uk/itm/TVR-350i-420-12v-ELECTRO...

[TVRTRICEY]

In regards to the Coil, I had a good chat with a gent from RPi the other day who said the Bosch Coils were far better than the Lucas one! Mine needs replacing so I think Il be going down the Bosch route, after all they are RV8 specialists! Obviously there will be an element of sales but I'd like to think he knows what he's talking about.

Tricey

[350zwelgje]

Bosch on mine based on a post many years back, of someone having a chat and/or tune by Mark Adams.

Rob

[adam quantrill]

I have put the old Lucas back on mine, the Bosch ones are fatter and don't fit the bracket the same. It was only changed as part of a speculative fix (turned out to be the rev limiter playing up).