New Owner, Hesitiation Problem?

[dalecrx]

Hi,

I am new to this forum as i have just purchased my first TVR Chimaera. Its a 4.0 HC in AVUS Blue. L reg with 60,000 miles.

Just one question!!

When driving at 30mph in 4th it does not like it as it tends to judder, so i drop it in to 3rd and its ok but it should be ok at that speed as the revs arent that low. Also when its ticking over it doesnt sound as smooth as it could do it sounds to be abit off balance.

any suggestions?

Im going to check the spark plugs, and get the timing checked as soon as i have the time.

Does anyone have any information on what the spark plug gaps should be on the 4.0 HC engine??

Thanks in advance

Dale

[danielson]

hello Dale, nice one for finding this forum, there is literally every answer out there..
couple of tips that may help you.

Do a search of the forum posts as your post may have already been covered..i did a quick search and the gap for your plugs is 35-40mm.

Get yourself a copy of The Bible, its THE reference guide to have for Chimaeras, again details of getting are in the Search archives.

enjoy your new baby..im jealous as hell as im still saving my pennies :-)

[hut49]

Welcome, Dale

Altogether lads: "Stepper Motor". Do a search and get it cleaned, as the first diagnostic step.

Re spark plug gap, the coil pulls a great voltage across the gap but not sufficient to jump 35-40mm! It's 35-40 thousands of an inch!

[Incorrigible]

danielson said:

..i did a quick search and the gap for your plugs is 35-40mm.

You'll also find that people quote stuff without reading what was said

I thought the gap was 6,000 miles

[danielson]

erm yeah soz about that..ignore me im a bit fik..

[bouffy]

30mph in 4th?

Try 30mph in 2nd. Sounds better...!

[pbrettle]

bouffy said:

30mph in 4th? Try 30mph in 2nd. Sounds better...!

Yeah thats what I was thinking - whats the revs at that speed? In general you will find the Rover V8 lumpy as hell at less than 1200RPM... some are better than others and its dependant on the fuel you use, but it should pull cleanly from tick-over (600-800RPM), but trundling around at 1000RPM it will buck and shove like a bad 'un....

Just let it have some more revs and keep in a lower gear... it might sound loud to you, but its not...

[dalecrx]

Cheers for the helpful advice!!

I will give the stepper motor a clean tonight! if i get the chance too.

Cheers

Dale

[the dodger]

The HC is a of a higher state of tune than the 4.0. I doubt if it will even idle below 1,000rpm and will not like trundling around at 30mph in 4th, even in 3rd it will struggle.

[Mark.S]

My old 4ltr was perfectly happy in 4th at 30mph. 5ltr will pootle along at 30 in 5th!

[hut49]

If you've got your head under the bonnet tonight also check that one or more of the spark plug extenders aren't fouling on the exhaust. Sometimes thay can loosen up and lie on the hot surface - look for signs of pitting on the exhaust as a give-away. If this is happening it can make it run rough at idle. Looking for sparks in the dark is one way but mind your fingers!

[dalecrx]

Where is the Stepper Motor located??

What does the stepper motor look like? shape?

I dont have the bible yet as i havent got around to ordering it.

IS there any site on the net that gives a pic of the engine with the stepper motor identified.

Thanks in advance

Dale

[hut49]

dalecrx said:

Where is the Stepper Motor located?? What does the stepper motor look like? shape? I dont have the bible yet as i havent got around to ordering it. IS there any site on the net that gives a pic of the engine with the stepper motor identified. Thanks in advance Dale

www.pistonheads.com/gassing/topic.asp?t=31504&f=9&h=0&hw=stepper+motor
Somewhere in a previous thread there's a photo - if you can't find it through the search facility, post again and I will go outside and take a pic of my Chim's.

[dannyboyo]

my 4.0l engine tends to stutter a bit when crawling along in any gear when the revs are below 1500rpm. These engines don't seem to smooth out properly untill 2000 - 2500rpm. Or maybe thats just mine. Took a while to get used to a slightly different way of driving i.e. dipping the clutch and rolling to a halt instead of crawling along using the engine.

Maybe a mark adams chip will smooth things out a bit. Do a search on it. Get more power and a smoother pickup.

[dalecrx]

If you could take a pic of the stepper motor that would be a great help, as i cant seem to find a pic on the search engine.

Thanks

Dale

[hut49]

Be gentle doing up the stepper motor - you only need to apply very little torque to seat it properly.

[the dodger]

Here's one I took out earlier. Note the guey mess which should be a fibre washer. I got a replacement washer from a plumbers and used liquid gasket with it.


It's a good idea to use a little PTFE tape on the thread when replacing after cleaning with carb cleaner or similar.

[etypejag]

I have a 99T Chimaera with 7000 mile on the clock that suffers the same problem.
It's been back to the dealer to sort this problem out, but after a complete engine health check-up, I was told that there was nothing wrong with it.
Its not the most refined engine, so I guess that we will have to live with it and drive everywhere flat out.

[hut49]

etypejag said:

I have a 99T Chimaera with 7000 mile on the clock that suffers the same problem. It's been back to the dealer to sort this problem out, but after a complete engine health check-up, I was told that there was nothing wrong with it. Its not the most refined engine, so I guess that we will have to live with it and drive everywhere flat out.

In the hands of someone who knows what they're doing it can be sorted. Presume you've told the dealer it's not right? Some dealers know TVRs but don't have an engine tuning specialist - if it spoils the enjoyment (and it needn't) get it down to a v8 specialist. A properly tuned v8 should be as smooth as silk.

[manek]

dannyboyo said:

my 4.0l engine tends to stutter a bit when crawling along in any gear when the revs are below 1500rpm. These engines don't seem to smooth out properly untill 2000 - 2500rpm. Or maybe thats just mine. Took a while to get used to a slightly different way of driving i.e. dipping the clutch and rolling to a halt instead of crawling along using the engine. Maybe a mark adams chip will smooth things out a bit. Do a search on it. Get more power and a smoother pickup.

It was a lot worse before Mark did the magic genuflections over it...