How do I make it smoother to drive?

[R8FUN]

I have had my 97 Griff 500 for a few weeks now & are really enjoying it.
But I am finding it a bit lumpy at low speeds, difficult to explain but like its hunting & you need to catch it by depressing the clutch.
It makes it difficult to drive in lots of traffic.

[citizen smith]

It might help if you say what speeds you are talking about. In my previous ownership of Griff 500's, anything less than 30 MPH - 3rd gear was necessary to smooth out lumpiness.

[R8FUN]

Crawling traffic speeds, once its up & running its fine.

[DVR V8]

Hi. From my own personal experience after 16 years of ownership the best thing i did was to replace all the ignition components to genuine[lucas/bosch] and get it on a rolling road. I did this 14years ago and difference was amazing ,the original timing was out, so it ran smoother, more economical, better acceleration. Also the two printouts i was given 262 bhp first run, 286bhp second run. Never missed a beat since. Hope this helps. Regards.

[O mage]

R8FUN said:

Crawling traffic speeds, once its up & running its fine.

Try it without vacuum advance, its only there to pull its socks up at idle or light throttle before the bob weights take over. The 5ltr behaves better without it.

[QBee]

Nip down to Chesterfield with it and get Joolz (KIts and Classics) onto it.
Not only can he check it over for you, he is one of the few people who can re-map the Lucas ECU.
And he has his own rolling road for the purpose.

[mk1fan]

There is the option to rip out all the old (and it was old when it was fitted in the factory) ECU, sensors etc... set up and install new. New, modern design injectors too. Transforms the car.

Costs attached though. Reselling the old components can offset these to a degree.

[davep]

mk1fan said:

... rip out all the old (and it was old when it was fitted in the factory) ECU, sensors etc...

How would a 14CUX ECU be considered old when fitted at the factory (it would already come supplied with the engine and harness anyway), if it was the current install for TVR and LR model years 1990 - 95? Granted it is old now, as is the car! GEMS came online in '95, but TVR kept it simple by continuing with 14CUX, and they must have had good reasons for that. Also 14CUX and GEMS both used Lucas disc injectors for their in-service life from 1990 to '99, again for good reasons. 'Modern' fixed disc, ball-ended pintle injectors didn't come into play until 1999 and Bosch Motronic

OP, if fitted, check that the Purge Valve, Carbon Cannister, hoses of EVAP system are all serviceable. Classic symptoms of EVAP system failure are:
• The engine may stall periodically when returning to idle
• The engine may suffer from poor idle quality.

[chris212]

Check out Chimpongas' write up on shunting. Biggest improvement for me was switching from ported to full vacuum.

[R8FUN]

Thanks for all the great advice, its due to go into X-Works at the end of the month for some cosmetic work. The previous owner had it serviced there for years, so I will ask their advice.
I guess the Gold standard is something like the MBE Powers solution, but I did want to keep it as standard as possible, not to mention the near 3K asking price!

[2 sMoKiN bArReLs]

All the above are correct.

All I'd say is that you do get used to it.

I especially like the days when the car won't idle at all. That combined with a pathetic handbrake leads to the wide foot on both accelerator & brake trick. (Honed over nearly a quarter of a century )

[Englishman]

R8FUN said:

I have had my 97 Griff 500 for a few weeks now & are really enjoying it.
But I am finding it a bit lumpy at low speeds, difficult to explain but like its hunting & you need to catch it by depressing the clutch.
It makes it difficult to drive in lots of traffic.

I've had two Griff 500's, the first for 4 years, the second and current one for 12 years and yours shouldn't be like that with good original components. I'm sure Joolz and others can go through the car methodically and sort you out for you without going for an aftermarket ECU. Might be as simple as cleaning and resealing the stepper motor, but I'd be guessing. Best to go through carefully or find someone that can.

[mk1fan]

davep said:

Stuff

14CUX was the final revision of their injection system. I'm not saying it was useless or didn't work but was it cutting edge?

CoG started a nice recent thread on new injectors that are direct replacements and offer current quality of fuel delivery.

[citizen smith]

R8FUN said:

Thanks for all the great advice, its due to go into X-Works at the end of the month for some cosmetic work. The previous owner had it serviced there for years, so I will ask their advice.
I guess the Gold standard is something like the MBE Powers solution, but I did want to keep it as standard as possible, not to mention the near 3K asking price!

The MBE is expensive, but it really does work well and makes the car feel a lot more responsive.

[phazed]

Or have an Emerald system fitted by Joolz.

I think you will find it is less than 3K.

An aftermarket ECU is the best solution long-term and neatens up the engine bay.

[lancelin]

I don’t believe any aftermarket ecu will make TVRs really smooth at low rpm, CAM and inlet manifold design need to be different. I have the canems and that has removed the nasty shunting.

[davep]

mk1fan said:

14CUX was the final revision of their injection system. I'm not saying it was useless or didn't work but was it cutting edge?

More stuff ... and by the final 14CUX code version, Operation Pride R3652, Lucas/Motorola had addressed most of the idle and smooth running issues but TVR didn't use it!

Was 14CUX cutting edge? Good question. As you appear to have in-depth knowledge of EMS systems used throughout the '90s, I'd be interested to know, in terms of technology, where Bosch, Marelli or Denso, etc., had the edge over Lucas. I suspect, in comparison, all systems were better in some areas, worse in others. Having looked at the 14CUX code in detail, it is clearly evident that there was a lot of effort being put into solutions for the upcoming move towards 'modern' emissions controls (especially Purge and EVAP) and more sophisticated diagnostics, which is where Bosch's Motronic and ME7 took the baton and ran. This is just an observation, I'm not an automotive/EMS engineer by profession simply an enthusiast keen to know how my car works.

[blitzracing]

Just run the CUX on the green map to get rid of the emission control. Leave a switch on the tune resistor so you can switch it back at MOT time, and run non ported vacuum as already mentioned. Total cost well under £100

[rigga]

Maybe an important question

What cam is fitted? Original and worn, or been replaced with something else previously, any history with the car?

[chj]

You need to ascertain what cam is in it first. If the cam has been replaced, it could be too lumpy and very difficult to overcome shunting whatever you do to ignition. Worth contacting Joolz too.