New Chim 450 - not firing on all cylinders

New Chim 450 - not firing on all cylinders

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Discussion

Richyp6970

Original Poster:

3 posts

1 month

Tuesday 25th June
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Hi all - newly joined - great forum. I've just bought a Chim 450 from a friend that has been in dry storage for nearly 9 years (he also has a Tuscan race car in there but I couldn't afford that!). I've cleaned it up and given it a good service and recommissioning - new plugs, leads, rotor arm, dizzy cap, coil, ig module, oil, air & oil filters, etc. To be fair the engine started well and runs ok but is a little lumpy and vibrates a bit. Removing the plugs in turn indicated No.4 is not firing although there is a healthy spark, and I removed the injectors and had them cleaned, checked and replaced a bad one. Its still not firing on No.4 and the cat (per-cat?) on that bank glows cherry red at idle, and there is a random 'detonation' crack noise coming from the front of the engine area. It seems like the fuel is there and the spark is there but not igniting in the cylinder. I thought it may have been a stuck inlet valve or similar so I've had the rocker cover off the evens bank but everything seems to be clean, oiled and moving nicely. I've also tried RG but no fault codes show up so I'm at a loss. Any thoughts or help please?

Belle427

9,244 posts

236 months

Tuesday 25th June
quotequote all
Id agree with the above, replacement components could be junk depending where you purchased from. If the originals are oem and look ok try putting them back on.
Did it run at all before you serviced it?

Richyp6970

Original Poster:

3 posts

1 month

Tuesday 25th June
quotequote all
Thanks for the replies. No it ran like that to start - I thought new ignition bits may solve it but no. There is 12v at the injector on cylinder 4 so it's getting power - but is the control signal from the ECU on the earth side? - so don't think it's the fuel side. And there is a strong spark without the extender so that's ok. I can't understand it. Would an air leak cause this type of misfire?

s p a c e m a n

10,860 posts

151 months

Tuesday 25th June
quotequote all
If it's just one cylinder then it's got to be spark, fuel or compression. Swap the HT leads about and see if it changes cylinder, same with spark plugs and injector. Swap the rotor cap, do a compression check, stroke the plenum and tell it that you'll give it a good clean if it behaves itself hehe

Stick a noid light (or just use the side repeater indicator) on the injector plug to see if it's firing

Richyp6970

Original Poster:

3 posts

1 month

Tuesday 25th June
quotequote all
Thanks all - I'll swap leads, injectors and plugs round tomorrow and see what happens

steviegtr

41 posts

9 months

Tuesday 25th June
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As said above I would go buy a compession tester , not expensive. To me it seems like everything is fine & why the precat is glowing. It is getting neat fuel from No 4 thrown at it. Creating a little jet engine in there.
Steve.
Hope you get it sorted .

Belle427

9,244 posts

236 months

Wednesday 26th June
quotequote all
The injectors are fired in a bank of 4 so I doubt it’s the trigger, you should have 12 volts on one side of them ignition on and you say this is the case so that looks ok.
You could examine the wiring to that particular injector but it sounds like it’s firing.

Paulprior

871 posts

108 months

Friday 28th June
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Yes the control for the injectors from the ecu is on the negative side, so constant 12 to the injector live side then the negative earths via the ecu in banks of 4