Mi16 strange issue

[Edp 67 3 Cars]

Ok, haven’t posted on here a while, hope all is well. 

 

Took my 1.9 mi16 out at the weekend for a few short journeys. On our way home the car became hesitant, suddenly misfired massively, backfired and cut out. I managed to coast the car into a bus stop and tried turning it over but nothing. It would crank and crank but wouldn’t start.
 

After around 20 minutes (of phoning mates looking for a tow)  I tried starting her again and it suddenly fired and I managed to drive home without any other issues. 

 

Before it played up the car was driving great right across the rev range and it was idling absolutely fine. 

 

I’ve ordered a new CTS as I’m unsure of the age of mine but apart from that do I put it down to one of those things or can I look elsewhere to find the fault? 
 

any help is appreciated 

[Bakes100 20 1 Cars]

Is it on standard Mi16 management? I've had similar issue in the past and it was the Ignition Amp, seemed to be due to high temperature. That may be something to start with if you can get a known good one to try.

[Edp 67 3 Cars]

2 hours ago, Bakes100 said:

Is it on standard Mi16 management? I've had similar issue in the past and it was the Ignition Amp, seemed to be due to high temperature. That may be something to start with if you can get a known good one to try.

Thanks for your reply.

 

Yes standard mi16 loom/ECU etc.

 

I’ll see if I can buy a spare one as I’ve got a box of spares that I’m unsure are any good or not… 

[SRDT 175]

Is the check engine light wired? Asking the ECU what's wrong can save you some time.

[pug_ham 244 3 Cars]

Have a look at this topic, there's a handy program attached to the first post, if you can get it to run on your laptop.

 

 

g

[Edp 67 3 Cars]

On 3/2/2022 at 10:09 AM, pug_ham said:

Have a look at this topic, there's a handy program attached to the first post, if you can get it to run on your laptop.

 

 

g

Thanks G, I’ll take a look. Hopefully going to have a tinker today and see if I can A, make the full happen again and B, remedy it! 

[SweetBadger 94]

Check the rotor arm hasn’t come loose. I had the centre bolt that secures it to the cam work loose - car misfired then stopped as per the symptoms you described.

 

Unlikely but it may be that it lined itself back up when you tried to start it again.

 

in my case I had to put the cap off and tighten it back on to get me home then get a replacement arm and cap, as the arm had damaged the cap making contact with it.

[Tom Fenton 1,541]

As it seems heat related i'd be looking at the ign amp. Maybe also the coil, I've had a couple fail on me over the years, but when they failed that was that.

[Anthony 1,003]

When it was misfiring and hesitating, what was the rev counter doing?  Was it holding steady relative to engine speed as normal, or was it fluttering around and dropping?

 

I'd be a little careful with new aftermarket ignition amps - certainly they used to be somewhat dubious quality and give issues, whereas even 30+ year old Bosch units tend to work reliably.  If you already have a spare Bosch unit that's fitted to an alloy plate, I would use that in the first instance.

[SRDT 175]

Some aftermarket ones are correctly listed as non compatible with XU9JAZ and XU9J4/Z, you can also have issues with the newer "black" bosch units.

[Edp 67 3 Cars]

Thanks for all the replies..

 

 

Ok so an update.

 

I had a play about with the coil/leads etc but nothing seemed untoward.

 

I took it out again last saturday and tried to replicate the fault but it drove perfectly. So sunday I treated it to a wash and hoover and took her out for a spirited drive. After around 25minutes I took it up a local private dual carriage way and gave it a decent thrash, it pulls like a flipping train and felt healthy and repsonsive.

 

As i pulled up at the next roundabout it died and I swore. I coasted it into a bus stop and switched it off. Tried turning it over sporadically but would not start. Unlike the first time it didn't respond at all. Luckily a good mate came to the rescue and towed me home a couple of miles down the road.

 

So i've got a box of spares and started with the ignition amp, nothing. Tried a new rotor arm and dizzy cap, nothing. Swapped the coil and bang it started first time. So I assume I've found the fault... so, Tom Fenton you recieve a cookie.

 

BUT

 

After starting it and letting it tick over I noticed this awful ticking/clicky noise. It sounds like a sewing machine. It sounds like a bent valve or something.

 

I havent checked the timing yet but did a compression test and got bang on 150 (odd) over all 4 cylinders. I read somewhere I should expect 190 - 220 so is my engine fudged?

I did the test both dry and with a squirt of oil down each cylinder and received the exact same results (as pictured)

 

So now I am at a loss. It starts and runs but sounds like something is damaged in the head. I'll jack it up shortly and see what the timing holes are saying. If it hasn't slipped a tooth where would you look...?  P.s I haven't been out for a drive since so I can't comment on performance or lack of it.

 

cheers guys.

[pug_ham 244 3 Cars]

Have you got a spare pair of the relay's usually in the black box somewhere in the loom?

 

I'm trying to remember the wiring diagram but doesn't one do the fuel pump & the other feed to the ignition side of the loom?

 

I've had similar where it was just a relay dying that was a dried out solder & nothing more than that.

 

Can't help with the compression issue, if it has one, or the noise. 

 

How loud was the noise, that could be a relay making & dropping the latch if it's fairly quiet, does it alter with revs?

 

g

[Edp 67 3 Cars]

11 hours ago, pug_ham said:

Have you got a spare pair of the relay's usually in the black box somewhere in the loom?

 

I'm trying to remember the wiring diagram but doesn't one do the fuel pump & the other feed to the ignition side of the loom?

 

I've had similar where it was just a relay dying that was a dried out solder & nothing more than that.

 

Can't help with the compression issue, if it has one, or the noise. 

 

How loud was the noise, that could be a relay making & dropping the latch if it's fairly quiet, does it alter with revs?

 

g

I tried both the relays in the engine bay but both are in good working order. Correct they do the ignition and fuel pump.

 

I 'think' i may have sorted the electrical issue its just this tapping noise now...

 

Loud, even with the bonnet down its an obvious tap that wasn't there when I started it first time on Sunday. Yes, the tap increases with revs. I have a horible feeling the head needs to come off.... I'm hoping to jack it up today and check the timing holes then I'll report back.

[Tom Fenton 1,541]

Only thing to add really, is it the exhaust manifold cracked or blowing? This can make a pretty crappy noise.

[wicked 103 3 Cars]

2 hours ago, Edp said:

I tried both the relays in the engine bay but both are in good working order. Correct they do the ignition and fuel pump.

 

I 'think' i may have sorted the electrical issue its just this tapping noise now...

 

Still I would replace the ignition relay. I had similar issues in the past and the relay had become unreliable; working fine most of the time and failing occasionally. 

 

Did you open the throttle while testing compression? 

 

The tapping could be a broken hydraulic lifter? 

[davemar 16]

Does the tapping sound change if the engine is moving car (so under load)? Does it change if you're in neutral or dip the clutch?

Have you got an automotive stephoscope which you could try and locate the sound a bit better?

 

I would be good if you could narrow it down before taking the engine apart. I had a sudden nasty rattling sound from my engine which turned out to be the flywheel had come loose, but only found out after taking most of the engine apart!