Misfire - my turn!

[celcius]

Hi keith
Good luck , let me know if you need a pump.

Greg

[adam quantrill]

Fuel pump issues cause poor fuel supply/low pressure which are more apparent under high rpm/lower gear/wide open throttle. Keith seems to be complaining about the opposite.

I won't rule the fuel pump out but my money is more on the ignition, followed by the CTS. The latter is easily/quickly/cheaply eliminated by shorting it out preferably at the ECU multiplug if you can (also eliminates the wiring to the CTS - the loom itself can introduce problems don't forget.)

As has been said higher up - ignition faults can come from the pickup in the dizzy (a coil), or the ignition amplifier, or the coil, then finally the HT side and plugs.

One lead/cylinder failing on its own can still introduce quite a misfire!

[KKson]

As Adam rightly says, it seems to be at lower revs when I have the problem. When it doesn't misfire it revs cleanly and all the way to the red line without obvious issue.

Small clip of what it sounds like as I come over the bridge, listen carefully! it does this every 20 seconds or so once it has warmed up and seems to get worse as time goes on.

http://youtu.be/FW_Rk6ZWpfE

[mrzigazaga]

Mmmm...You could be right Adam....Mine happened more on heavy load where fuel pressure was needed at max...Its definitely worth replacing the coil..Perhaps ignition amp..Check plug connections..What i do is change one thing at a time then drive it to see if it has changed that way you have a clearer answer to offer anyone else when its their turn...

The beast has a bit of flu...He'll be okay soon...Incidentally what is the layout on the gauges from left to right ..The first one looks like battery level?...They look good at night..Your lights are bright....For a Wedge

[rev-erend]

throw a new set of plugs in there for starters. Perhaps they are fowling.

Edited by rev-erend on Sunday 15th February 22:28

[KKson]

All sorted - it was the coil so new Lucas replacement fitted for £17. With new coil and new dizzy cap I'm not sure if it's my imagination but it seems to be going like stink and is way more responsive.

Quick clip of test drive. Oil pressure dips a bit as I ease off. The rest of the journey it was fine at just below 50psi so not sure why it dropped off.

https://www.youtube.com/watch?v=1wZuOORQ0IM&fe...

mrzigazaga said:

Incidentally what is the layout on the gauges from left to right ..The first one looks like battery level?...

Mark from left to right, fuel, temperature, oil pressure and battery.

Thanks for the very useful replies lads and the offer of further help had it been needed. Cheers.

[celcius]

Great its fixed , enjoy.

[mrzigazaga]

Sounds good mate..The acceleration in whatever gear you were in..(4th ?) was smooth..The oil pressure was increasing when you got up to..Ahem speed... and then it dropped off..Have you checked the oil lately?...I know it does fluctuate but i never thought as much..Mind you most of the time I'm accelerating i look out the windscreen and not at the gauges,...Might be nothing..Could even by electrical?....Happy days are here again...

[adam quantrill]

50psi is a bit high to start with - unless it's cold.

You should be seeing 30-35 psi top at full chat when fully warm, and around 20-25 when idling after warmed up.

[mrzigazaga]

adam quantrill said:

50psi is a bit high to start with - unless it's cold.

You should be seeing 30-35 psi top at full chat when fully warm, and around 20-25 when idling after warmed up.

Yeah this is what i get normally..Occasionally mine goes up to 50psi, Especially when I'm motorway driving..

[KKson]

At idle mine is around the 12 to 15psi mark, when the engine is hot and at 2000 to 2500rpm it's about 35psi, but when the engine is not totally warmed up is does sit around the 45 to 50psi. Test blast was about 4 miles. The clip was after about 1.5 miles. I checked the video for the last leg and it was around the 40psi mark. It has just had new oil and also a new oil relief valve as it was sticking and sending pressure spikes of up to 80psi on occasions. I'll keep my eye on it, but just pleased to have found the reason for the fault.

[adam quantrill]

That sounds about right oil-wise - nothing to worry about.

Good job finding the misfire too - reminds me I must swap back to my original coil...

[V8 Fettler]

KKson said:

All sorted - it was the coil so new Lucas replacement fitted for £17.

Good news, was the coil from a known supplier?

[KKson]

V8 Fettler said:

Good news, was the coil from a known supplier?

Yep. ANG - got both the coil and dizzy cap from them - service was fantastic.

http://www.angclassiccarparts.co.uk/

[V8 Fettler]

Ta, I've had a couple of poor experiences with an ignition amp and and a dizzy cap recently (from another supplier), so always useful to know of a reliable supplier.

[Wedg1e]

V8 Fettler said:

Ta, I've had a couple of poor experiences with an ignition amp and and a dizzy cap recently (from another supplier), so always useful to know of a reliable supplier.

In an emergency (or in my case a lot longer ) the ignition amp from a Metro is a plug-in replacement for the one on the side of the RV8's 35DLM8 distributor - and oddly, usually rather cheaper to boot

[bradderztvr]

Good news, you've got it sorted and not too costly. We'll have to have a blast out soon......but I'm due to get on with full suspension replacement in the next few weeks, but will then be wanting to give it a good road test !
Right..... Jack and axle stands out, warm clothing, message to The Mrs...."I'll be in the garage for a while"