Rover v8 mx5 won't rev up

[scudderfish]

Whereabouts are you? Update your profile with your location.

[Rover v8 Mx5]

Profile updated with location. I'm based in ripon.

[ChrisJC]

Another thought - the distributor is one tooth out. As the engine speeds up, the rotor arm is too far away from the metal points inside the distributor cap to make the spark cross.

Try retiming it from first principles.

Chris.

[Rover v8 Mx5]

Hey guys,

Good news!!
I've got it to rev properly.
I've taken the dizzy cap off and twisted the arm and felt alot of slack. Twisted left as much as possible and she will now rev freely.

Does this mean my dizzy is worn?
I'll upload a vid also, she's running on all 8 by the sounds now too.

Thanks all for your input so far, I'd be lost without the forums!

Cheers
Rowan

[ChrisJC]

There should be a lot of slack - it's the motion used to alter the timing with engine speed - the centrifugal advance.

But it does indicate a timing issue for sure...

Chris.

[Rover v8 Mx5]

Would this indicate the centrifugal weights are sized?
Is there any way to co firm this prior to replacing the dizzy?

Thanks all!

[GDCobra]

Is it really this simple to run forced induction with a 14CUX, simply plumb in the charger and it will take care of itself? I’m surprised at that.
Although the system has a MAF I thought the fuel calculation was primarily based on RPM vs load so I’d have expected some mapping or other changes needed to allow for MAP values > atmospheric. Maybe not.

Seeing as tweaking around with your dizzy seems to have yielded some success I think I’d be giving the ignition side of things a good check over making sure everything is in spec’ not forgetting simple/basic stuff like timing pointer position. Frequently out on RV8s particularly if damper and/or pointer from different engines.

A simple and cheap dumb timing light should be good enough for you purposes, less to mis-calculate WYSIWYG.

If you do get this running fight it will be a flying machine. MK1 MX-5 is < 1ton I think so power to weight will be “favourable” and their handling isn’t too shabby. Always seems like a good idea to put a V8 into a British sports car. Good luck.

[stevieturbo]

Would this indicate the centrifugal weights are sized?
Is there any way to co firm this prior to replacing the dizzy?

Thanks all!

If the weights were seized, then the arm would not move relative to the drive shaft.

Simple way to be sure...take it apart, turn it, look.

And of course check timing with a timing light to see if things behave as they should

This is really basic stuff.

As for GD and is this as simple etc

Well doing it right. Absolutely not. Currently it massively seems to be a "wing it" and see approach, with really no thought as to how it works, what is needed etc etc or checking if any of it works or is suitable.
People do get away with many things...but a little learning and understanding of the basics first, goes a long way

[Rover v8 Mx5]

Hey guys,

I certainly have a wing it and see attitude! IT by trade and that's how we do things

Car cost me next to nothing and the plan was to spare it out. If she's running and driving it's a bonus, and certainly will be keeping the car now.

https://youtube.com/shorts/5zpi_Bpu_T8?feature=share

Took her for her maiden voyage today, and it's safe to say it's an absolute beast, the torque is unbelievable, it will light up the wheels in 3rd if you boot it. Supercharger is pushing an unhealthy? 12psi into the engine, however I'm going to reduce this with a different pulley I'd imagine this is way too much boost.

I've got my local indie doing the dizzy and timing chain (I have a wallet-unhealthy obsession of new belts/timing chain) as I want to ensure its bang right, recently found the owner is a rv8 wizard.

Cheers guys,
Updates to follow

[GDCobra]

Hey guys,

I certainly have a wing it and see attitude! IT by trade and that's how we do things

Car cost me next to nothing and the plan was to spare it out. If she's running and driving it's a bonus, and certainly will be keeping the car now.

https://youtube.com/shorts/5zpi_Bpu_T8?feature=share

Took her for her maiden voyage today, and it's safe to say it's an absolute beast, the torque is unbelievable, it will light up the wheels in 3rd if you boot it. Supercharger is pushing an unhealthy? 12psi into the engine, however I'm going to reduce this with a different pulley I'd imagine this is way too much boost.

I've got my local indie doing the dizzy and timing chain (I have a wallet-unhealthy obsession of new belts/timing chain) as I want to ensure its bang right, recently found the owner is a rv8 wizard.

Cheers guys,
Updates to follow

I think I’d definitely be investing in a wide band AFR gauge just for peace of mind if nothing else. It will mean you’ll have to get a bung welded to the exhaust for it and do a bit of wiring (nothing too complex).
It would be interesting to know what the PO did to get it working with the 14CUX, I have heard of this being done but never chased it up as I don’t expect to go the FI route.



I did look at this company:
https://www.sc-power.co.uk/pages/sc-pow ... rgers.html


A while ago, they indicate still using the 14CUX with a re-chip which indicates it’s doable. Do you know what injectors it’s running.