12 replies to this topic

[ZeroT]

This one has me stumped. I've got a K reg sprite, standard, 1275 on a HIF38 carb and electronic dizzy.

 

While driving at a steady speed there will be a sudden complete loss of power, and the engine is unresponsive to the throttle. After rolling along for 10-15 seconds or so trying to find somewhere to pull over it'll come back to life and drive again, only to repeat the process. A few times it has stalled out completely.

 

I can park up and rev the nuts of it with no problems at all, equally off the line and using all of the rev range 1st, 2nd and 3rd it pulls away and is as nippy as ever. It only seems to be an issue while holding a steady speed at a normal rpm for that speed/gear. I thought it might be the coil and put in a new coil, plugs and leads but it's exactly as it was before.

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Edited by ZeroT, 30 June 2019 - 11:54 AM.

[andyapanel]

Do you lose everything, or just the engine?

 

Have you checked the battery leads are tight?

If they are OK, prime culprits are the HT parts, then look for dirt in the carb.

Good luck

[cal844]

What coil did you fit?

Check and clean all connections including earths.

If that doesn't work check the resistance of the coil, our 998 had an issue where it would cruise perfect except in 4th where there was a lack of power.

We tried fitting a coil from a known working car with the same ignition setup, it worked for me... If it works for you theres the issue.

Hope this helps

[unburntfuelinthemorning]

I had a weird problem like this.  Yours may be completely different but have a look, it might help:  http://www.theminifo...ignition-fault/

[Ethel]

I'd agree with the consensus that it's ignition related if it instantly cuts out. Try running 12v direct from a brown wire terminal on the fuse box or solenoid. That'll eliminate the ignition switch and other possibilities so you can concentrate on the ignition itself - you will need disconnect the wire to turn it off, but you could loop it inside the car to do that with a switch. Disconnect all the wires on the coil other than your new +be and those to the amplifier module.

[cooperd70]

I've had has you describe. Even though I had fairly new plugs in I replaced them along with the leads and that solved it.

[johnR]

I currently have a similar problem - runs fine until about 50mph then splutters and loses power, after slowing down it recovers and is fine again. I've tried immediately turning the ignition off and checking the float chambers - normal level of fuel. 

[richmondclassicsnorthwales]

Check you have oil in the carb dashpot,    always overlooked and is a problem which can cause this type of scenario

[luismx123]

Had the same many weeks ago. Was the float chamber needle valve that was binding. Then I got the new "uprated" version from minispares and that made it worse. Literaly only happened when driving at speed, quick shut off, sometimes smell of gas and then jumps back on. 
Got the newer type viton???? tipped needle valves for the float chamber and been good since then, Might be something to check.

[gazza82]

The viton tips are more resistant to the ethanol in fuel too I've read

[ZeroT]

Ok so a little update.

 

The new coil I fitted was the GCL143 from mini spares, along with 4 new plugs and all new HT leads.

 

I have tried driving with the fuel cap off to make sure there isnt a vac issue with the tank.

 

I've sprayed WD40 all around the carb to see if there is an air leak and I cannot find one.

 

I've cleaned out the carb, twice now, but I also did a full rebuild on it with an official kit about 8-9months ago, which included the viton needle.  The dashpot oil is also fine.

 

Yesterday I fitted a glass fuel filter as it's never had a filter before and I was interested to note the number of bubbles in the system, does this suggest an aire leak in the fuel lines somewhere, even theres no fuel leaking from any of the lines.  Sorry about the audio, I kept blocking the mic with my hand.

 

https://youtu.be/hhd06-QQ90U

[MiniMadRacer]

When you are driving and this happen what happens if you pull the choke out ... if that "improves" things its fuel related.. also make sure the fuel line is as far away from the exhaust as you can get it in case the fuel is vapourising in the line

[richmondclassicsnorthwales]

You did not say after all the previous posts - Is there oil in the carb dashpot ??

 

This can cause an engine to die