All,
This is very helpful feedback. Thank you SO much... I've run out of ideas, so this is great!

OK, so for the weekend, my plan is:

1. Check fuel lines, replace fuel filter.
2. Fuel Harness: Make the #1 Injector wires include one good POS and the other NEG power to Injector Wires.
3. Check the connection to the Injector wires to the Injectors.
4. Verify the Spark is solid. I may try one of those in-line spark plug test lights… I hate getting shocked... Ok, I am a complete coward when it comes to such things.

I will try those things and hopefully it figured out… or at least an idea of what to check next.

One other question:
When I swapped out the Spark plugs, we got the Platinum type that have a really small electrode thing… I assume those are OK. Any concerns there? I normally work on old Alfa Romeos and they are a bit picky about Spark Plug selection. Are there any issues like that with Minis?

Thanks all!
Cervantes

 

I've had two sets of platinum plugs in my '03 for quite a few years with absolutely no issues. You should be fine as long as they're the right plug for the application.

 

Ok, I did a few tests tonight... I​​​​​I think we have a fuel issue.

On cylinders 2-4 when I put a stethascope on them I get a definite "clicking" sound. But nothing on#1!

Putting power directly to the injectors when they are out, and all 4 clicked.

So we swapped injectors. Still no click on#1. So I'm thinking, not the injector.

So we are down to wiring, yes? Well for all 4 it seems that the + for both is always on, and the ground on both comes on and off... So why no click on #1??

Is there Proper way to test the wiring to the injectors? The only fuel injection I am really familiar with of the mechanical injection on Alfa's... This is yours different!! I'm not really sure how to treat them.

But I'm leaving towards computer or wires?

Thoughts?
Cervantes

 

I was just looking at the wiring diagrams for the ignition and injectors for you earlier.

See page 52 of this pdf.

On all 4 injectors the + side is always hot when ignition (ie: engine starting/run) is on. The DME then switches the - side of the injector to ground at the precise timing for each injector sequentially.

For a layman it is not that easy to test the drive electronics in the DME. You best bet is to verify continuity from the injector -ve terminal all the way to the ECU. If the wiring is OK, then it is the coil driver for #1 in the DME is toasted. It pays to properly diagnose though.

 

Just a thought. I would check the DME connectors are properly reconnected after the tranny work. It is possible the pin was bent, or the connector not fully seated. This is the box on the right side of the air filter box.

Not too hard to bend one of these pins:

 

All of the DME Connectors look straight. I am trying to figure out how to test the continuity on the 2 wires from the non-firing Injector to the computer... The pins are much smaller than the probe on my meter.... and so far my attempts at improvising a wire I can access have not worked.

But it SEEMS like it would have to be either the wires or the computer itself.

I am leaning towards the computer... But I will see if I can get the resistance on those wires to be sure they are good.

Thanks all!
Cervantes

 

Ok, I got back to the Mini and have another update... Last week I thought I had it narrowed down to a bad injector, the computer, or the connections in between. Because there was no tick from infector #1.)

​​​​​So I borrowed one of those Noid test light things. With the Noid tester I found that it actually did send the signal - for about 15 seconds... Then it stopped. Hmm. Plugged the wires back into the injector and had my son start the car while I listened to the #1 injector. It ticked for about 15 seconds then stopped.

So it seems that something is shutting it off...

I unplugged the #3 injector wire and put on the Noid thing. Same result: 15 seconds of clicking then stopped. So when the injector wires are disconnected, I think the computer figured it out and shuts it off.

So now I am thinking... Something is telling the injector that something is not working on #1 and shuts off the signal to the injector.

So my question now is, ... What conditions can cause the signal to the injectors to shut off? Does anyone know how that all works? Is there a list of what the computer would check for that would shut it off.

All can think is maybe it has low fuel pressure and it is not reaching#1 with enough fuel and that causes the computer to shut off #1. I got a fuel pressure guage but it locked The adapter needed to connect it to the rail. I'll try to find that tomorrow.

Thank you so much for the help.
Cervantes

​​

I hope that all makes sense

 

I read on another thread that the computer does not shut off the signal to the Injector... is that correct? If so, What else might cause the Noid test to fail after about 15 seconds of flashing (or the "tick" at the injector (as heard through a stethoscope)) to stop after the same time?)

The more I think about it the more confused I get!

The error code says Misfile on #1, and the car runs rough. When I listen for clicks on the Injector, they work for about 15 seconds then stop. When I put #1 on the Noid tester, it does the same... light flashes for 15 seconds then stops. Noid Tester on #3 does the same, though when plugged in, it continues to "click."

That makes me think that something causes the signal to shut down after 15 seconds (ish) when something is wrong... So what faults would cause that to happen?

I am stumped and welcome any ideas.

Thanks,
Jeffery

 

You have done some good work trying to diagnose the cause. The Noid tester and the result you found is interesting that is shut off the injector after 15 seconds. I see no reason to doubt that the ECU indeed shut it off after determine #1 misfire. Let me just say I have no tribal knowledge when it comes to many Mini specific EFI, knock detection, ECU management policies etc. I am just trying to think like an engineer.

I would recommend to retrace the events. I think the biggest clue is your problem started right after the clutch replacement. From carefully reading the thread it was done by a shop. It is all too coincidental that the car run like crap after the work. If it were me I would not suspect #1 cylinder mechanical, like compression, burnt valve etc. I would immediate try to find out in the course of the clutch replacement what electrical were disturbed.

There are two approach to replacing the clutch - remove the front subframe and drop the transmission/clutch assembly; or pull the entire engine in lieu of dropping the subframe. On the latter most people remove the main engine harness, which is totally unnecessarily. Doing so disturb a lot of ECU engine sensors. When it comes to car electric/electrons, especially those exposed to the harsh elements, the less you disturb them the better.

Anyway, to me the knock sensor is suspect even though the car (if I have not mistaken) only has one sensor for all 4 cylinders. I think ECU algorithm relies on crank and cam timing sensor to as timing reference to determine which cylinder the knock sensor is reading. While I say suspect the knock sensor there are other sensors and actuators on the engine harness too and if one is compromised who know what effect it would have on the ECU.

You replaced the coil pack and the spark plug cable. I didn't not see you did replaced or at least swap the spark plugs. If indeed you missed to verify one most important thing. A plug insulator can have hairline crack and compromise the spark generated.

It is too hard form us to try to help troubleshoot not being in-situ.

 

Just want to say, I had my knock sensor unplugged for about 150 miles inadvertently before it threw a CEL. Car ran fine.

Jeffrey - I don't know about why it would shut off after 15 seconds. The only thing I can suggest is test all 4 while you're there to see if there's variation. You said both cyl 1 and 3 have the cutout... What about 2 & 4. If 2 & 4 behave the same way I don't think that's your problem.

 

I still don't know what the issue was, but wanted to give a short update. I ran out of time, money and ideas for a while, so I have not worked on her for a while. But now my wife is pushing to get it running before snow falls, so I am back on it.

I'm thinking I need to test the Fuel Pressure at the engine, but my pressure gauge does not have the right attachment to do that...

I will re-read the posts sent before and see if I can get any ideas as well.

Short of that, I am thinking I need to bring her to the shop. My only concern is that I am not close to any shops that really know Minis (or really ANY European make cars.)

I will update the group when I know more in case anyone is interested.

Thanks all and have a great day!
Cervantes

 

So I finally got a fuel pressure giraffe that works and it's showing about 50 PSI... Revving it up and down it fluctuates between about 42 and 50.

I'm thinking that is about normal, but can't seem to find anything to verify that. Does that found about right?

 

I can't confirm anything about the fluctuations, but I've seen a lot of references to 3.5 bar fuel pressure. That puts your idle number just about right.

https://www.northamericanmotoring.co...m-misfire.html

^^ this guy's numbers are the same as yours so I'd assume yours are just fine.

 

I know this is an old thread now, but I wanted to update the group so y'all know the outcome.

So I gave up on the diagnostics and it sat for months... This week we brought it to a neighborhood (non-Mini Specialist) mechanic. They said it has low compression on the #1 cylinder and suspect the rings...

I'm still trying to decide what to do. Wrecking yard engine? Sell it for parts... Or pull the engine and do a limited rebuild. How big of a job is it to do new rings and all? Anything worse than other cars? That may be our best option.

Anyhow, thank you so much for the help when I was trying to figure it out. This feels like the worse possible news, but at least we think we know what is happening.

All the Best,
Cervantes

This really surprised me since we did do a compression test, So I am going to get the car back and re-verify that.

 

Thanks for the update, as we all want to know the progress.

Did your neighbourhood mechanic tried to narrow down if it the rings are bad or the valves? I suspect more likely is a valve. If all he/she did was compression test that is only a cheap and dirty step to say cylinder #1 is definitely no good.

If it were me playing the Meister mechanic, I will pour in some oil into the cylinder to see if the compression increases. If so that supports the rings are not sealing.

What mileage is the car?

 

^^

I was going to ask why he jumped to rings.

 

It has about 100,000 on it.

The guy at the shop said he was almost certain it was rings. When I pushed him for more details, he said it was possible (though he thought unlikely) that it could be valves or head gasket, BUT that he strongly suspected the rings because of the "wet test."

I assume "wet test" is just when you pour oil down the cylinder to see how that impacted the compression or not. We never called it that, but I assume that is what he meant.

I'm hoping to pick the car up tomorrow and hopefully I can talk to the mechanic that actually did the work, and I will ask for more details. I would love for it NOT to be the rings.

I also want to re-do the compression test. I'll try it both "dry" and with oil added and see what happens. I'll review those tests on the internet to make sure I am not missing anything.

I would be more confident in a head gasket or even valves more than rings... If it is rings, I may just look for a wrecking yard motor. But not sure. Kinda sad to have gotten the bad news, but we'll figure it out.


Thanks All!
Cervantes

 

I am not sure which would be better, rings or valves. Needing new rings is just a simplistic statement. Unless the Mini engine is known to eat rings but not causing other expensive problems generally the pistons, cylinder, and may be even bearings can have considerable wear. For me, I would it rather the cylinder head than the half block. A complete proper rebuild engine will cost you. Junkyard engines can be like playing Russian roulette. One bullet or two?

 

Well, another month has passed! I was laid off at work on Christmas (last day was Dec 25th!), so I have a little more time to work on it now... and a greater need to get this fixed!

The reason the mechanic believes it is bad rings on #1 is because the compression was lower when he tested dry, and higher when he tested with some oil down the cylinder.

Fair enough, but I don't trust him at this point. So I re-did my compression test.

My Compression Test Findings
The engine was not up to operating temperature, having run for about 3 minutes before the test. This Mini is not Supercharged.

Initial Cold-ish / "dry" test:
1. 160# - 2. 178# - 3. 176# - 4. 176

So #1 is about 18# lower than the others.

Added oil down the cylinders and retested each:
1. 210# - 2. 210# - 3. 205# - 4. 210#

So adding some oil brought them all up to the same level. I am thinking that indicates rings on #1...

Or does it? I would have assumed #1 being at 160 PSI with only 18 PSI variance, I would think it might decrease economy and performance. But what I am experiencing is cylinder #1 is non-operational! Pull the Spark Plug Cable - no change. (But it does have decent spark).

What do you experts think? Rings, or "keep looking"???

Remember the NOID Test showed FI for the first 15 seconds then stopped... I thought that might be the computer shutting it down because of the misfiring - but it runs bad those 1st 15 seconds as well... I am starting to suspect the computer.

Any feedback would be awesome!

Thanks all!
Cervantes
PS, I am going to re-run the "dry" test tomorrow, but maybe warm it up more first. But not add oil.

 

OK, I think that was too much info just to get to my question (My wife says I do that!)

Bottom line. With cold / dry compression one cylinder at 160, 168 below the others, and all equal with oil added, would that cause the thing to run on 3 cylinders? Or do I need to keep looking?

I just don't want to replace the engine and still have the same issue! (If it comes to that.)

Thanks again. Sorry for being so long in my replies.

Cervantes.