Misfire on idle B230FK 940

[ie940]

Update on this, I've flashed fault codes on engine and ignition ECUs - there were none.

I would quite like to try two ECUs to rule that out.

I can chuck in some ATF, sounds good. I am planning to pull the head and maybe rebuild my spare head to go back on.

[Rversteeg]

I missed the bit about you having replaced the injector, but couldn't the problem be in the wiring to the no. 1 injector? Not sure if the leads are long enough, but as all injectors fire simultanuously, you could try swapping over the connectors of injectors one and two. How about the valve clearances on no. 1 cylinder?
I shouldn't expect any significant wear in a B230 engine after 225.000 km. Mine almost tripled that and is still idling and running fine.

[ie940]

My engine's on 150k.

I had indeed swapped an injector to a known good one and ohm tested them all. I have a suspicion it's injecting fine as it'll pop in the exhaust, but stop when you pull the injector wire off.

Valve clearances are all good across the board, all within spec.

[960kg]

Strange how we all learn by what we have done and also what has happened to our own cars?

But what keeps my mind going back is the fact that the OP says the misfire at idle gets worse as it get warmer or hotter so therefore one should be able to rule out a burnt valve or even tappet /valve clearance.

I had similar at one time years ago and all i remember was it was a Ford.

The Kent Engine had oilways and waterways very near one another at the front (water pump end) of the head gasket......leading to the amount of gasket to the cylinder was limited and my engines HG had a very small blow in the shape of a straightish line which joined a waterway to the cylinder.

When cold the misfire was damn nigh impossible to detect because of the choke on but upon warming up the coolant also got hotter and is pressurised by then and so caused a worse misfire?

So maybe the start of a bad HG going West!

[Rversteeg]

Originally Posted by ie940

Update on this, I've flashed fault codes on engine and ignition ECUs - there were none.

I would quite like to try two ECUs to rule that out.

I don not see how the ECU could be at fault as it does not "know" which cylinder is firing. It simply puts an injection signal to all injectors simultanuously, independent of the crankshaft position. The ignition is also a common signal which is only led to a specific cylinder by the rotor in the dizzy cap. So there is no way a faulty ECU would only target cylinder no.1.

[Laird Scooby]

Originally Posted by 960kg

Strange how we all learn by what we have done and also what has happened to our own cars?

But what keeps my mind going back is the fact that the OP says the misfire at idle gets worse as it get warmer or hotter so therefore one should be able to rule out a burnt valve or even tappet /valve clearance.

I had similar at one time years ago and all i remember was it was a Ford.

The Kent Engine had oilways and waterways very near one another at the front (water pump end) of the head gasket......leading to the amount of gasket to the cylinder was limited and my engines HG had a very small blow in the shape of a straightish line which joined a waterway to the cylinder.

When cold the misfire was damn nigh impossible to detect because of the choke on but upon warming up the coolant also got hotter and is pressurised by then and so caused a worse misfire?

So maybe the start of a bad HG going West!

Certainly a possibility and one i was going to suggest once the other things were eliminated. I still think it's something simple thogh, the red block engines are pretty robust units to start with.

I had a Marina (1275cc) that did very similar to your Kent powered Ford, sadly what had caused the HG to fail in the first place was a partly blocked rad (which obviously got worse after the HGF) and that lead to the head resembling crazy paving there were that many cracks in it!
Replaced the head and rad from a breakers (guaranteed bits) and unbeknown to me the rad was also blocked so the head cracked again.
While waiting for them to source the bits under the guarantee, it wheezed its last on the A33 (pre-M3 link to Southampton) one morning on the way to work.

[360beast]

Originally Posted by Laird Scooby

Considering most ATFs have a viscosity of about 30, it's not going to throw the viscosity of a 10W40 out that much, especially in 10-20% dilution in engine oil.
It also contains "Seal Swell" to help revive and condition the rubber seal throughout the engine.
It still contains certain detergents not present in engine oil and has a better "creep" action than engine oil. For this reason, to plagiarise a lager advert, it reaches the parts other oils can't reach. This makes it particularly good at getting past carbon, gum and similar residues left by engine oil, dissolving the worst of them and freeing hydraulic lifters, piston rings, cleaning blcoked oil separators and so on.
It also has friction modifiers that help reduce friction.

A few cases of success, most recent first.

A friend recently bought an MX5 that had 3 noisy tappets and a leak from the front crank oil seal. Added 0.5L of synth ATF after an oil/filter change, now totally silent and leak free - also goes a hell of a lot better due to restoring lost compression due to sticky piston rings being released.

My own 760 had suffered from neglected oil/filter changes so the oil separator was badly clogged. Also quite noisy in general and when i first got it, lucky to achieve 19mpg on a long run. Granted i've done other remedial work but the oil separator is now a lot cleaner, the emissions are better and economy is up to about 26mpg doing mainly short runs, i have seen 37mpg on a longer run.

Jeep Cherokee 4.0L HO Limited, predecessor to the 760 - when i first got it, it had at least 3 noisy lifters that sounded like 3 pile drivers in the engine when cold. Oil leaks from various places round the engine including the rocker cover (rubber gasket) and was prone to a cloud of blue smoke when either applying power or after coming off the power and slowing on engine braking.
Oil/filter change (the old oil was very clean), replaced 1.25L of engine oil with synth ATF (Carlube ATF-U) and within a few hundred miles the tappets were quiet, the blue smoke had disappeared and i was getting 24mpg on LPG, also went like stink!

My Rover 827 Coupé - again had suffered neglected oil/filter changes and when i first got it, only ran on 4 cylinders, would chuck out a big puff of blue smoke when blipping the throttle or giving it some beans.
Engine flush, oil/filter change and added ATF-U, within minutes it was running on all 6 pots, emissions have got cleaner year on year with continued use and blue smoke reduced.

My last 740GLE - wasn't too bad in general but again, the engine was dirty inside, barely scraped a pass on emissions the day i got it. A year later the MoT guy put it back on the ramp after the emissions test as he wanted to find the cat! It didn't of course have a cat and was running K-Jetronic injection.
Also the power and economy were well up on when i first got it.

My 827 Sterling - on the whole very good but suffered noisy tappets as the C27 Honda engine is prone to having. Now silent after treatment with ATF-U and errr, oh yeah, i've had 43mpg out of it on a run and wasn't hanging about either! Also i have quite a few emissions print outs from MoTs that show an improvement over the years i've owned it.

There are others i could cite but they are all pretty much the same story. The tip was given to me about 30 years ago by a mechanic who had in excess of 30 years experience at the time, i've also known many other mechanics recommend it, many have never heard of it admittedly but i can assure you it works.

In short,

don't knock it until you've tried it!

Try it I shall then, 84 360 front crank seal is leaking and various other places. The car is on sorn and needs restoring plus the engine if I do restore it and don't part it out won't be staying in there (low compression b19a is pants) so doesn't matter if it does damage it.

[ie940]

Fixed. Massive leak on inlet gasket cylinder 1. Some idiot had fitted the gasket so badly half was covering the port and half was hanging off the edge so letting air in. Worryingly been like that since I bought it two years ago.

[Laird Scooby]

Glad you found the problem, strange it's taken this long to show up as a problem though!

[mocambique-amazone]

Originally Posted by ie940

Fixed. Massive leak on inlet gasket cylinder 1. Some idiot had fitted the gasket so badly half was covering the port and half was hanging off the edge so letting air in. Worryingly been like that since I bought it two years ago.

Nono, they are prone to "wander" into the port. Turbo more often than NA. Normally cyl4, the one at the bulkhead. Nobody told you before to spray with brake cleaner at running engine around the manifold? Strange, I didn't read the whole thread because of scrappy mobile monitor.
Glue the new one on both sides. It should last 3-5 years. Best is to use phenolic spacers with glued gaskets on both sides.
Regards, Kay