Rover V8 misfiring and won't start properly

[TGF188L]

Thank you everyone for your answers. I will look into them. Just fyi re the spark plugs, they were changed to see if that was the issue

[JON1D]

If you have good fat spark and it runs only when hot look at fuel delivery. The mixture could be weak on start up. Is it carb or fuel injection?
Start with looking at spark plugs. Colour tells you a lot and are they wet?
Fuel pressure check psi carb 5-6 psi or injection 60psi.
Fresh fuel as E10 is awful when standing.
Static time cylinder 1 on compression to set tdc which I am sure your mechanic would of done.
1-8-4-3-6-5-7-2 clockwise rotation.

  Front
Left- right
1     -2
3     -4
5     -6
7     -8

[KevinW]

Have you checked the spark plugs? Worth removing a few to check for soot deposits and correct gap.

Have a look round the carb - are there any vacuum intakes (look like small narrow spigots about 10-20mm long) exposed? If not already connected to a rubber pipe on the carb, then these should have a plastic bung/cover on them. I am wondering if one got pulled or knocked off during the distributor change over, and so your carb now has a sub-optimal air/fuel mixture.

May be of use:
http://www.clubcobra.com/forums/small-block-talk/89953-holley-carb-vacuum-hookups.html

[Chris]

When satisfied with the ignition set up, the next checks would normally be vacuum leaks and fuel system .
The mechanic should or will know this fault finding proceedure ,
Let me know what you find ,

Chris.

[Chris]

If your mechanic will work with you and not take offence, it sometimes can be deamed teaching your
grandmother how to suck eggs !
I would suggest that he checks that the distributor splines are correctly aligned with the camshaft and he is
100 % sure that the leads are correct on the dissy cap, it is easy to get this wrong as is the plug leads to the
correct cylinders .
Make sure he is aware of the distributor direction of rotation .
Hope to not cause a storm and you get sorted .

Chris.

[TGF188L]

I am relying on the mechanic here, but he comes well recommended and is a racing mechanic.

The distributor was replaced because of the fault. He was of the opinion the distributor was at fault so replaced it with an electronic distributor. Sadly the bonnet wouldn't close with that one, so it was replaced with the electronic insert to the existing distributor. I am not a mechanic nor very practical so I could be talking twaddle here.

Yes I am pretty sure the leads are on correctly and in the right order. It was the first thing the mechanic thought of when it wasn't cured. Also once warmed up, after quite a lot of time, it fires ok, which to me would indicate the new distributor is working ok and the leads are on the right plugs. or am I making a stupid assumption?

Thanks for your help Chris.

Keith.

[Chris]

Are you sure you have the correct firing order and have the plug leads on the correct cylinders ??

[Chris]

Just a quick question,
Why have you replaced the distributor and have your issues started due to the replacement ?
I await your response, I may be able to give you some advice, the more info you can give me / others will most certainly help .
Chris.

[TGF188L]

I bought a Cobra February 2025 and it has been running fine. Takes two squirts of the accelerator and will start first or second time even if left for a few weeks. Now it takes forever to start and then only on a few cylinders and with backfires. The distributor and coil has been replaced with an electronic insert, the plugs and leads replaced also. The mechanic is at a loss. Once warmed up it will go, but that is after about 30 min. It will take 30 odd attempts just to get anything out of it and then another 20 odd goes to get it running on a few cylinders.

Help I am desperate. The mechanic has run out of ideas.

Cheers Keith.