Chris as you said this all started with bad gas. When I got my 88 Acura running it had sat for 5 or 6 years. I had all sorts of problems with it, for months almost a year. First one of the values keeps sticking due to old gas that had turned into varnish. I cleaned the intake several times, It did not work. Finely I took the head off and had a machine shop clean it and put a new valve in it. It still stuck. I had to take it back to the machine shop a second time before this problem was fixed. Then the Gas tank had a little rust in it. I went through several filters before I took the tank and had it cleaned. Then a fuel pump and another filter. Even the gas gage did not work it was stuck. I could not free it. So I put it back in the tank with hope it would free up after sitting in gas. It worked after a few months it started working and has worked sense.
So long story. Sorry but I say all this because it started with bad gas. You may have to go thorough the hole fuel system and give it a good cleaning to fix the problem. You have been very through and I just don't know how you have hung with it this long. I would have set it on fire by now. Anyway I thing you should go back to basics. You know the full was bad and that was when it started. I would go over the hole fuel system and make sure its clean. Make sure a valve is not sticking due to bad gas, double check the injectors.
Also on my car it would Idle ruff because of the sticking valve but if you got it above 2000 RPMs it ran smooth. It did have a flat spot but I can't remember at what RPM.
Good luck. If I had a layover there I would come help.
All they needed was the ECU/EWS and key. They even sent me a video showing my ECU/EWS in action but I did wonder how they used my key?
Ah yes I've thought about buying a bloody big gun and shooting it up!
Yes you are correct. There is a saying: " You can't see the wood for the trees" so as you say I need to go back and go over everything fuel related which might mean the head coming off and all the valves out(worse case) but the idle is smooth as is above 4000rpm.....just that 2500 to 3500rpm range.
First issue is to figure out why the filter does not work and why the fuel pressure pulsates.
Still the good thing is all the parts I replaced were with 130,000miles so no harm done, just I could done replacing over a longer period of time LOL
Today it is raining like crazy so no work tonight.
So I decided to run the engine with the V belt off. The popping in the exhaust increased but the misfire took longer to appear. Also on the day before this problem started I put on a new Vee belt as the other was slipping. The new Vee belt was 5mm shorter, so last night I put the old belt on. The misfire now does not happen at 2500rpm, actually I can very close to 3000rpm and hold it there without misfire but I can hear the popping starting to increase as I move up to 3000rpm , I can hold it there for much longer until the misfire kicks in.
I took a look at the Alternator which had a ton of black dust around it and it was getting really hot. I have a get me home spare alternator in the shed so although it was a bit rusty I fitted it instead of the current one. Now the misfire range is less 3000-4000rpm . Maybe the both alternators are bad? also I pulled the plug on the PSP just to see if that is draining the voltage but even with that not working the misfire is still there.
Hahaha funny. One thing is I know how to remove the gearbox! Changed the throw out bearing Now I'm changing all the old parts back to the newer parts. Also maybe I have found the issue. Stay tuned
The balancers are relatively inexpensive. I changed mine about a year ago while chasing a misfire. Not sure it helped (we changed a couple of sensors too) but it was piece of mind...
You're dedicated, Chris. I'll grant you that. Me...I'd have invested in some C4, a timer, and given that Coopah a decent "fare thee well" a long time ago. :devil:
I thought about that. The PSI was the same on all 4 cylinders. I thought to pump air into #3 plug hole and see if air comes out #4. Should have done that yesterday with the valve train off.....DUH! should have/could have
Chris you are the most persistent person I know. Keep at it you will get there. Rally is a drug & that is what keeps you going! Best of luck friend. :fingerscrossed:
ah ha...the fault is spreading to other Mini's....don't read this thread unless you want the curse of the misfire!
I don't know what is more frustrating? not knowing the issue or knowing what the issue is but don't know how to fix it!
Last I ran the same tests again. The V belt off is limited due to the engine will overheat. So while the engine was cold I ran without the V belt. So the only rotating part was the new pulley. Guess what? the fault range narrowed again. Now the fault happened just at 3500 and took about 2 minutes or more to go to 3 cylinders. Then I fitted(don't laugh) several elastic bands from the pulley to the water pump and ran some more. The same thing happened. 3500rpm. So the water pump and tension wheel are excluded as potential suspects.
I then put the V belt on then did the T-map test but this time I hooked up a shop vac to the T-map to simulate some suction. The engine ran a little better but was running way to rich and very rough. Switching the vac on and off didn't make much difference, like before the engine did not go to 3 cylinders.
Based on those 2 tests I would doubt that the sensor is so sensitive that rotating parts would cause a misfire, if that is the case I bet 50% of Mini's would be misfiring!
I think the pulley helped with the misfire because after changing it the only cylinder to deactivate is now #4. Guess where the crank sensor is??? at #4.
With the T-map it seems the pressure in the intake gets to a certain pressure that is working with the crank sensor/ECU to cause the misfire. The crank sensor is new but looking at the above the crank sensor is in the middle of both tests.
Another interesting thing is the cheap scan reader shows voltage to the ignition and main relay. The ignition is a constant 13.6V but the main relay read 13.6, 12.8, 0.0, 13.6 etc repeating like that, 0.0V for a split second can't be good. There are 4 main replays that control all the sensors,injectors and ignition. I suppose it is possible one or all have carbon build up?
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