74 replies to this topic

[rane]

Hello to all! I've already gained a significant amount of knowledge from this fantastic forum. Thanks to all of you who spend countless hours providing information and helping others.

I've wanted a Mini since I was a boy and told myself I would never buy one unless it was local to me (driving distance), was drivable, LHD (sorry guys I promise I'm usually a purist), and RED. I finally found one meeting all these criteria and bought it.

NOW I have a problem. I've posted this on the minimania forums and was led here for more information.

http://www.minimania..._buys_dream_car

In Summary:
The car was billed as a 1974 Austin Mini with conversion - reported 1991 Rover 1.3 engine - LHD
Now I'm discovering that the engine is newer and an MPI

The previous owner knew very little about the car.

I drove it home about 200 miles and it lost power on the way as well as lost use of the tach. I limped home on what seemed to be limited power. The car will periodically (usually in a higher gear) backfire, lose power, and then upon a change in gear returns to its previous diminished power but remains very functional.

I have been told by my mechanic that the center two cylinders are not firing. A coil pack was recently replaced by the previous owner and the mechanic believes it is a faulty ECU because of the tach and non-functional cylinders. Many ideas have been weighed in and the belief on minimania is that a faulty ECU is less likely.

Tach function has been a problem for a while according to previous owner and the fuel gauge does not work either but he believes this are different problems since the fuel gauge is an old problem.

The oil temp gauge works.

Can anyone help me help him work this problem out?

Thanks so much to anyone who can provide any help! I've been shopping on this forum for a long time and dreaming about one day being an owner and am excited to have the car.

Some images:

[Fast Ivan]

are you getting a spark from all the leads?

[Fast Ivan]

if you are not getting a spark i would suggest looking at the coil pack first, the tacho is connected to the coil pack i beleive, when it was changed was it for a new unit?
if you are getting sparks on all leads then its commpression test time.

[nev_payne]

MPI's have a wasted spark on all strokes so if you were to be getting 2 firing only, I'd expect over-run at least. Get it diagnosed properly with a laptop or diagnostic kit, ECUs aren't exactly cheap.

[4V8s]

well ive just bought mine too (an mpi) but from what I have already got to know about these cars, I would agree to point at the coil pack, or the order of the HT lead connections to the cylinders.

Its basically a twin coil, so cyl 1&4 go from one and 2&3 the other. So as both 2 and 3 are not firing, that coil could have failed. This suggests the ht lead order might be correct, as if they were crossed between coils then you would get misfires and backfires, but likely either 1 or 4 and either 2 or 3 then not firing, if you see what I mean.

but, as a simple initial check - there are 2 ways these coil packs are arranged it seems, so the guide in the Rover workshop manual might not be right.

On mine, cyl 2&3 operate from the top coil, so top row next to each other and 1&4 the bottom row. As its a wasted spark system, if 1&4 are swapped OR 2&3 it shouldnt matter, but if 1&2 or 3 or 4 and 2 or 3 are swapped, you will have problems.

looking at the coil pack, lower left should go to cyl 1, then clockwise from there - so upper left to cyl 2, upper right to cyl 3, lower right to cyl 4, Cyl 1 is right side by the expansion tank.

if that doesnt work, then you can try the order in the manual. which is cyl 1 lower left, then anti clock from there. I guess this would work if the two coils are paired vertically rather than horizontally.

Anyway, if none of that helps or makes a difference, then as others said, test for a spark and if none on 2 and 3 then faulty coil. It would be unusual for the ecu to fail in that way.

Also, check all grounds - fuel guage not related but also could be a faulty ground, or the sender in the tank, or the guage its self.

Good luck!

[jaydee]

Whats wrong with LHD if you drive on the wrong side of the road..

2 cylinders not firing on a mpi... a compression test is the very first thing to do.

[xrocketengineer]

When the tachometer acts funny isn't that caused by the crank position sensor? At least that is what happens with the SPI and it also has little to no power.

[4V8s]

by the way, one more thing, you said it was sold as a '74 with late engine conversion.

To me, everything on this car points to it being a late '96 onwards car, a proper facory built MPI. as there would be sooo much to change relatively speaking from a '74 to make an MPI with all the right bits.

for example, you have the front mounted rad, this requires different inner wings so unless you have slats on the right side of the engine as looking from the front into the wheelhouse, then this is an MPI thing. and inner wings are some work to change.

Also, you have the wider screen seal and what looks like vin number etched into the windscreen. Again - pretty sure thats a 97MY onwards thing. You also look to have the later cooper interior. Do you have an SRS airback in the steering wheel and 2-speed fan? again - only on 97MY cars onwards. Would all seem way too much work to retrofit onto a '74 car? I also spy a bonnet slam panel switch for the alarm system/immobiliser. Again - only a late car thing.

Personally I think you have bought an original MPI rather than a '74 converted car. But I am often wrong!

Looks nice by the way!

Edited by 4V8s, 17 January 2013 - 11:46 PM.

[rane]

are you getting a spark from all the leads?

Still waiting to hear from my mechanic. Thank you very much for your help in troubleshooting!

[rane]

if you are not getting a spark i would suggest looking at the coil pack first, the tacho is connected to the coil pack i beleive, when it was changed was it for a new unit?
if you are getting sparks on all leads then its commpression test time.

Great info. I was suspicious of the pack to begin with. Not sure how legit the information or repair was from previous repair job.

[rane]

MPI's have a wasted spark on all strokes so if you were to be getting 2 firing only, I'd expect over-run at least. Get it diagnosed properly with a laptop or diagnostic kit, ECUs aren't exactly cheap.

Do you think most mechanics in the US would be able to evaluate using a diagnostics plug or is special equipment required?

[rane]

well ive just bought mine too (an mpi) but from what I have already got to know about these cars, I would agree to point at the coil pack, or the order of the HT lead connections to the cylinders.

Its basically a twin coil, so cyl 1&4 go from one and 2&3 the other. So as both 2 and 3 are not firing, that coil could have failed. This suggests the ht lead order might be correct, as if they were crossed between coils then you would get misfires and backfires, but likely either 1 or 4 and either 2 or 3 then not firing, if you see what I mean.

but, as a simple initial check - there are 2 ways these coil packs are arranged it seems, so the guide in the Rover workshop manual might not be right.

On mine, cyl 2&3 operate from the top coil, so top row next to each other and 1&4 the bottom row. As its a wasted spark system, if 1&4 are swapped OR 2&3 it shouldnt matter, but if 1&2 or 3 or 4 and 2 or 3 are swapped, you will have problems.

looking at the coil pack, lower left should go to cyl 1, then clockwise from there - so upper left to cyl 2, upper right to cyl 3, lower right to cyl 4, Cyl 1 is right side by the expansion tank.

if that doesnt work, then you can try the order in the manual. which is cyl 1 lower left, then anti clock from there. I guess this would work if the two coils are paired vertically rather than horizontally.

Anyway, if none of that helps or makes a difference, then as others said, test for a spark and if none on 2 and 3 then faulty coil. It would be unusual for the ecu to fail in that way.

Also, check all grounds - fuel guage not related but also could be a faulty ground, or the sender in the tank, or the guage its self.

Good luck!

AWESOME! Thanks a million. I can't wait to get up with him. We were really starting to scratch our heads and I've never had to just get a new ECU. Hopefully this will provide some insight.

[rane]

Whats wrong with LHD if you drive on the wrong side of the road..

2 cylinders not firing on a mpi... a compression test is the very first thing to do.

I just didn't want to get out of the car to go get fast food. You know how lazy and fat us Americans are.

[rane]

When the tachometer acts funny isn't that caused by the crank position sensor? At least that is what happens with the SPI and it also has little to no power.

Thanks!
Anyone else on this?

[rane]

by the way, one more thing, you said it was sold as a '74 with late engine conversion.

To me, everything on this car points to it being a late '96 onwards car, a proper facory built MPI. as there would be sooo much to change relatively speaking from a '74 to make an MPI with all the right bits.

for example, you have the front mounted rad, this requires different inner wings so unless you have slats on the right side of the engine as looking from the front into the wheelhouse, then this is an MPI thing. and inner wings are some work to change.

Also, you have the wider screen seal and what looks like vin number etched into the windscreen. Again - pretty sure thats a 97MY onwards thing. You also look to have the later cooper interior. Do you have an SRS airback in the steering wheel and 2-speed fan? again - only on 97MY cars onwards. Would all seem way too much work to retrofit onto a '74 car? I also spy a bonnet slam panel switch for the alarm system/immobiliser. Again - only a late car thing.

Personally I think you have bought an original MPI rather than a '74 converted car. But I am often wrong!

Looks nice by the way!

I am starting to agree with you and was wondering how all of the "updating" was possible. I don't know anything about the history. It might have quite a strange one. Cars of this age generally are not in the US. Yes to all of your questions. Is there any way to tell its year and destination country. There aren't many countries with LHD Minis are there?