Running On 3 Cylinders :-(

[Livelee 0]

So far I have replaced:

 

Plugs

Leads

Rotor

Cap

Coil

Ignition Amp

 

Is there anything I can do to cure the problem? What else should I replace?

 

Many Thanks

 

Dan

[t16ryan 1]

Have you done a compression check ?

[BERTMAN 40 1 Cars]

a mate of mine had the same problem on his XR3i, and had to replace the ECU

[Livelee 0]

Have you done a compression check ?

 

No, that's next on my list of things to do. (well it's below "get a compression tester" on the list actually)

[M@tt 77]

Try pulling the spark plug leads off one at a time in turn to try and identify which cylinder is giving you problems if you think it's running on 3. You should find if it is running on 3 pulling the affected cylinder lead

off won't make a diference to way it runs.

 

When you find which one it is, remove the spark plug and check you're actally getting a spark on that lead that way you can rule than out.

 

also double double check you've got all the leads on the right way round if you've had them off, wouldn't be the first to have put them on the wrong way round, myself included!!

Edited November 11, 2006 by M@tt

[Livelee 0]

Cheers M@tt, i'll try that 1st thing tomorrow morning.

[MikeT 0]

Just to let you know of a simliar problem I had on my own 205 Mi16 running on 3 last year (compression test was all good so..) turned out to be a poor connection on one of the two small wires running into the injector; so it wasn't fueling properly..must have knocked it out when working on the car - took me ages to find what the actual problem was!pushed both the cables home and it was running on 4 again. Might be worth a look, fingers crossed its a simle fix - Good luck with it mate.

 

Cheers

 

Mike

[Grahamrally 0]

As said before really, get a compression tester and do the test. Incredibly worth while, rules out so many things mechanically before replacing lots of bits and pieces. It could be head gaskets, rings, piston, block, liner, valve related, but without doing the compression test to make sure it's a-ok you can't rule them out. Once you've done that all you have to do is work out whether you are getting spark and fuel to each cylinder.

[chris1986 1]

when mine was doing this it turned out to be the head gasket, it still held good pressure though, which still puzzles me

[Livelee 0]

when mine was doing this it turned out to be the head gasket, it still held good pressure though, which still puzzles me

 

I've just done the HG.

[vince 0]

check your injector, connection as said above, and may be the injector itself...

 

vince

[jackherer 543]

Just to let you know of a simliar problem I had on my own 205 Mi16 running on 3 last year (compression test was all good so..) turned out to be a poor connection on one of the two small wires running into the injector; so it wasn't fueling properly..must have knocked it out when working on the car - took me ages to find what the actual problem was!pushed both the cables home and it was running on 4 again. Might be worth a look, fingers crossed its a simle fix - Good luck with it mate.

 

Cheers

 

Mike

 

thats exactly what I was about to write, but Mike has saved me the bother, its worth checking them

[Livelee 0]

Just bought a tester and done the test. Looking at the engine from the front left to right:

 

1:160/165

2:150/155

3:170

4:180

 

All cylinders hit those values within 4 turn overs. Another thing I noticed when doing this was that I'd put the injectors back the wrong way round (4,3,2,1 rather than 1,2,3,4). I thought that might be the problem so I put them round the correct way but the problem is still there. I guess they fire all the time and not in a set sequence? One other thing that I thought was strange, plugs 1 and 4 were wet and black, plugs 2 and 3 were white and dry. These plugs have done less than 10 miles since going in. The 4 old plugs were all black and wet.

 

I've got a track day booked in 3 weeks. I'm not confident i'll make it :-(

[Livelee 0]

Thought i'd update this as there has been some more findings.

 

Just to give a bit of background: The car was faultless till the HG went. I sent my head away to a tuners to be rebuilt into a replacement head that had been skimmed and pressure tested. Since putting it all back together the car has never been "right".

 

Thinking i'd maybe damaged something electrical in the rebuild process i've replanced the whole ignition system...to no avail. RTeplaced the fuel filter and checked all the injectors flow a decent amount of fuel.

 

Today I did a leak test. Using a compressor on each cylinder with the piston at TDC the inlet valves leak incredibly badly. Taking the rocker cover off and checking the valves some are stuck and others are lose when the bucket is on the back of the cam.

 

Where do I go from here? has the head been rebuilt correctly?

 

Many thanks for any help

 

Dan

[Faz85 0]

Is it the valve guides which are causing the leak or the valve seats? Was the head actually rebuilt, or did they just skim it and bosh it back in?

 

I would probably have the head off again, and do valve stem seals and get a re-seat done...or try and source a known "good head"...that might be easier.

 

Faraz

Edited November 18, 2006 by Faz85

[Livelee 0]

My head was sent away and all of the bits were taken out and put in a new head.

 

Anyway...since writing the above and going to watch James Bond, my mechanic (Dad) has still been working on the car.

 

He put the plugs back in and turned ot over a few times on the starter. This seems to have sealed all the valves again as there is no leaks now.

 

We'll give up looking in the engine for a problem now and investigate the electrical side of things.

[paul205mi16 4]

i been keeping up with ya post and my mi is doin the same and i replaced all electrical componants inc ecu to no avail. hope u find the fault soon m8, as for mine im waiting till ive got enuff money for another loom to try.

good luck

[Alastairh 47]

Right do as all said above.

 

I wouldn't thought it would be a compression problem, as you have fairly acceptable psi out on all 4.

 

First off, Check all the ht connections on the Dissy cap to see if there firm.

 

Then, do as Mike says (i've done it before), take each injector plug off one at a time, and check both connections and give it a blow, so that ruels that one out.

 

Then do as Matt says, and just un clip each lead off the plug as the car is running and tell which plug isn't getting spark due to the engine noise changing, or put a spare plug on the end of each lead as you turn the engine over.

 

Then come back to us with your findings.

 

Alastair

[nick 3]

Also have a look down the plug holes and see if there is any water or oil sitting in the bottom. Mine had a misfire and it was water in the plug hole shorting out a plug.

 

Nick

[Alastairh 47]

Yeah.

 

Just got my brothers Mi running, but on 3. Need to grab a fresh set of plugs.

[Livelee 0]

Put it backtogether today, started 1st time and sounded fine when it was warming up. As soon as it was driven it all went s*it again. Back in the garage and the lumpiness seems to come and go as you rev it in neutral. As soon as it's driven it's rubbish.

 

Getting depressed and run out of ideas now.

[returnofjim 0]

Ive had a similar problem to this recently, it was after replacing the cams with catcams in a brand new 2.0 MI/S16 engine. When the engine went in the car it ran fine for a short while then started running on 3 all of a sudden. I removed all the lifters, drained them of oil and stuck them back in.

 

Voila....problem solved

 

Hope this helps

[Livelee 0]

That's a good suggestion. Had an auto electrician look over the car today. Everything electrical seems to be fine. He thinks the cam timing is a little out. We'll be looking at this over the weekend.

[Livelee 0]

Just some more updates for this thread (as I hate "problem" threads that end withou a conclusion)

 

We checked the timing today and it's all fine. Checked over everything else and started replacing the new bits with the old bits. Turns out the new ignition amp was a crock of s*it and the car is miles better with the old one back on.

 

The car is missing on cylinder 1 (next to the cam belt) All the plugs are burning lovely but number 1 is wet when we take it out. Also with the car running removing the lead makes no difference to the engine note.

 

We trailed the car to a garage this evening and he will be checking it tomorrow. The mechanic is a mechanic for an RAC rally team so if he can't resolve it i'll torch it.

 

On the plus side of todays events we found a pair of Weber 40's in the shed so i'll be putting those on. 6 days till bedford trackday so no time really before then.

Edited November 26, 2006 by Livelee

[yeti-dj 7]

I recently did a servie on my dads Saab 900 turbo and it ran fine then refused to start, after changing all the parts you suspect, coil ign amp etc it turned out that 3 of the new plugs had die! very odd but chucked old ones bad in and she ran fine. Spoke to a mate who is a mechanic and he has had this a few times.

 

hope this helps.