Mi16 Cutting Out When Warm

[DGTi 0]

Hi All, more help required please!!Lol

 

I picked up the 205 this weekend, well I tried to anyway

 

I got about 5 miles away from the garage and it cut out, and wouldn't restart it was just cranking on the starter and, at best, spluttering a bit and backfiring spectacularly!

 

After about 5 minutes of poking about at plugs without finding a loose one it was suggested to adjust the AFM screw, which I did, and there was a difference, for the worse! So I turned it the other way and it started!! I'm wasn't sure weather it was this adjustment or the fact the engine had cooled that allowed it to re-start, but I carried on never the less.

 

About another mile up the road the same thing happened again!! So I pulled over and tried the screw again to no avail (I couldn't remember which way I was turning it) and the engine wouldn't even splutter at this point, just kept turning over on the starter.

 

I had the car towed back to the garage and the mechanic has had a look at it today for me. He has just rang back to say that he managed to adjust the AFM to allow the car to re-start this morning but it again cut out when hot, and wouldn't re-start!

 

So he adjusted the AFM and got it to start when warm and it would rev normally warm.

 

He then allowed the engine to cool back off for a few hours and came back to try it again and with the AFM set when warm it wouldn't start cold!?

 

I have searched the forums about AFM's and read a lot about idle issues but nothing describing my symptoms! Is the AFM knackered or is this just a symptom of another component not working properly, that we're compensating for with the AFM!?

 

Sorry for the long post, so close to having this on the road its unreal it was like a little tease session on Saturday - painful!!lol

 

Cheers

Andy

[welshpug 1,626]

check the coolant temperature sensor.

[Miles 331 1 Cars]

AFM has nothing to do with your issue's, the screw adjusts the CO to a limit, As above check the CTS and ignition amp as these show these issues when warm

[DGTi 0]

Just rang the mechanic to see if he did check that as we discussed it on Saturday.

 

He said that its literally 1/4 of a turn on the AFM thats making the difference so he has stopped at that, but will check the sensor for me now.

 

I have asked him to look at removing the AFM cover to see the condition of it, or, as I have read else where that the plastic cover warps and restricts the movement of internal components... has anyone else tried that??

[DGTi 0]

Hi Miles,

 

I did think the Ignition Amp, but this has been retained from the original engine and is a bosch part, that matches the dizzy. It is, however, mounted on the gearbox on a reduced sized Ali plate made from the original by the company (Constella) that did the electric side of my conversion... could this be an issue with over heating??

 

So is there no-way a faulty AFM could result in the engine cutting out and not restarting / backfiring when warm? Just odd that the 1/4 turn seems to be making a difference?? Could it not be that the AFM is sticking when warm, messing up the air/fuel mixture, and turning the screw just free's it back up momentarily?

 

Got the mechanic looking at the temp sensor as we speak!

Edited July 8, 2013 by DGTi

[welshpug 1,626]

is it on proper Mi16 Motronic management or 8v Jetronic stuff and a dizzy adapter?

[DGTi 0]

Sorry its a 1.9 Mi16 (DFW) on proper Mi management, with a new Mi16 Coil, and retained Ignition Amp.

 

The wiring was carried out by Constella with lots of wires replaced in the loom and new relays.

[Miles 331 1 Cars]

Get the amp on the car body, Having it on the box isn't the best place for it by any means, There is or should be ample wire to do this back to the OE place

But backfiring I;ve only had when the Rotor arm started to break up on a car I picked up for a mate of mine much to the dismay of the owner as it went wrong during a test drive so sold it dirt cheap.

 

I've never seen a AFM make the car backfire or cut out, Even if you move the arm inside by hand they still run to a degree before cutting out but only that and nothing else and they re-start straight away

[welshpug 1,626]

do you mean misfiring rather than backfiring Andy? quite a different thing!

 

like a stumbling uneven idle.

[Simes 248 2 Cars]

The only time I've had back firing on an mi (when it was on motronic) was when the alternator gave up and then it was all over in 5mins.

 

Another for ignition amp (hideous things when old!)

[DGTi 0]

do you mean misfiring rather than backfiring Andy? quite a different thing!

 

like a stumbling uneven idle.

 

Well it does have a poor idle as you describe, but when I got it re-started the first time it was popping and cracking and banging like mad until it cut out again!

 

 

Get the amp on the car body, Having it on the box isn't the best place for it by any means, There is or should be ample wire to do this back to the OE place

But backfiring I;ve only had when the Rotor arm started to break up on a car I picked up for a mate of mine much to the dismay of the owner as it went wrong during a test drive so sold it dirt cheap.

 

I've never seen a AFM make the car backfire or cut out, Even if you move the arm inside by hand they still run to a degree before cutting out but only that and nothing else and they re-start straight away

 

The wiring loom I bought from Ecosse was in a really poor condition, and to get the Amp plugged on the passenger wing caused the rest of the loom to be pulled from under the inlet manifold! So I guess the guy at constella re-located it to avoid any damage to the wires. Is it worth chopping the plug and having extra length added to it so I can re-locate the Amp? Is this a heat dissapation issue??

 

Would the rotor arm give an intermittant issue like I have? Worth a look inside I suppose!

 

Ok so I can assume that whilst my AFM might not be working 100% as it should it wouldn't cause the issues I am having!

 

Cheers

[DGTi 0]

The only time I've had back firing on an mi (when it was on motronic) was when the alternator gave up and then it was all over in 5mins.

 

Another for ignition amp (hideous things when old!)

 

Really? I thought the blue Bosch Amps were worth keeping hold of?? Can you get the bosch ones new anymore?

[farmer 327 1 Cars]

Really? I thought the blue Bosch Amps were worth keeping hold of?? Can you get the bosch ones new anymore?

 

Pug have stopped selling them. I have one in my loft if you want a new unit would be willing to sell.

[DGTi 0]

Pug have stopped selling them. I have one in my loft if you want a new unit would be willing to sell.

 

Cheers Farmer, how much would you want for it? Are they all the same or would we have to compare numbers?

 

I'm going to take the dizzy apart this Friday to see what condition thats in, and also check the CTS is working correctly before I replace anything.

 

Also I'd like to know if its the mounting of the Ignition Amp thats causing the issues rather than the component its self, is there anyway of testing that its working correctly when up to temp? No point fitting a new one if its the mounting plate ect...

 

Cheers

Andy

Edited July 9, 2013 by DGTi

[farmer 327 1 Cars]

Cheers Farmer, how much would you want for it? Are they all the same or would we have to compare numbers?

 

I'm going to take the dizzy apart this Friday to see what condition thats in, and also check the CTS is working correctly before I replace anything.

 

Also I'd like to know if its the mounting of the Ignition Amp thats causing the issues rather than the component its self, is there anyway of testing that its working correctly when up to temp? No point fitting a new one if its the mounting plate ect...

 

Cheers

Andy

 

They cost £104 if still sold from Pug. I got one for Andy Williams for his 405 MI16 so would assume they are the same but don't hold me to that.

 

I would want £75 posted as I would need to buy another back for a spare. Is a lot of money but if you want genuine Bosch that is the going rate from Pug. Try and find a Bosch stockist may be able to help?

 

There should be heat transfer paste there for the amp as well.

Edited July 9, 2013 by farmer

[Simes 248 2 Cars]

Really? I thought the blue Bosch Amps were worth keeping hold of?? Can you get the bosch ones new anymore?

 

When my ignition amp was being silly I spent ages sourcing an identical brand new one from Bosch. funnily enough it didn't work - missing at certain parts of the rev range. A couple of other '8v' ones I had also were quite particular. In the end Miles sorted me out with an older Bosch one (2nd/3rd hand) and it was fine.

One of the reasons I changed ECU and went wasted spark.

[DGTi 0]

Ok Cheers Farmer, I'll see what I can work out this weekend before I buy anything!

 

 

When my ignition amp was being silly I spent ages sourcing an identical brand new one from Bosch. funnily enough it didn't work - missing at certain parts of the rev range. A couple of other '8v' ones I had also were quite particular. In the end Miles sorted me out with an older Bosch one (2nd/3rd hand) and it was fine.

One of the reasons I changed ECU and went wasted spark.

 

How did you know that it was your Ignition Amp causing you the issues Simes??

 

If I definetly knew what was causing the issue I could try some new / replacement parts, but given how hit or miss the Amps sound I could buy one and be fooled into thinking that the issue is somewhere else beacuse 2 of them don't work!Lol

 

Does anyone know how hot too hot is for the Amps to work at, as I assume they get fairly hot even when working normally?

[farmer 327 1 Cars]

Ok Cheers Farmer, I'll see what I can work out this weekend before I buy anything!

 

Just let me know. Plenty of pattern options out there but whether they are up to the job I don't know. Certainly I have had no faults since I replaced mine with a genuine item.

[Simes 248 2 Cars]

Ok Cheers Farmer, I'll see what I can work out this weekend before I buy anything!

 

 

 

How did you know that it was your Ignition Amp causing you the issues Simes??

 

Mine was missing under load, around 3-4k rpm. A bit of research and trial and error - it never cut out.

[farmer 327 1 Cars]

Mine was missing under load, around 3-4k rpm. A bit of research and trial and error - it never cut out.

 

Exactly the same symptoms as my car had Simon,

[DGTi 0]

Morning All,

 

No luck this weekend I'm afraid... I swapped out the Ignition Amp for another one, and after an encouraging start up with a strong idle, after a mile of driving the mis-fire was there still, and I limped back into the garage before the engine cut-out again!!

 

I went round the rest of the ignition system, cleaned up the distributor contacts and tested that all the sensors were in working order, which they were.

 

Following lots of testing and head scratching I am at a loss, there is fuel and spark and it just won't start (Or when it does it cuts out within 30 seconds) when warm! The only thing that improves the chances of re-starting the engine is unplugging the AFM... I know it makes no sense but thats just what it does!!Lol

 

Anyway I have decided to stop chasing my tail with this now as I am always going to be waiting for it to break down again, and am looking to update the system to wasted spark!!

 

When my ignition amp was being silly I spent ages sourcing an identical brand new one from Bosch. funnily enough it didn't work - missing at certain parts of the rev range. A couple of other '8v' ones I had also were quite particular. In the end Miles sorted me out with an older Bosch one (2nd/3rd hand) and it was fine.

One of the reasons I changed ECU and went wasted spark.

 

How did you go about modernising your ignition system Simes!?

 

Talking with the mechanic on Saturday he has suggested that I look into getting a Megasquirt piggyback ECU system.

 

I have done some reading up on this at the weekend but I have never looked at this type of thing before so its all new to me, has anyone here done this before?

 

From what I have read up I believe that if I purchased a Megasquirt 1 v3 it should work fine with the standard engine sensors, with the exception of the Mi16 TPS, and I would need to introduce an intake air temp sensor in place of the AFM.

 

Would I also require a wide band Lambda sensor to allow the Megasquirt to manage the engine properly or is this optional??

 

Then would it just be a case of obtaining a suitable coil pack to replace the Ignition Amp, Coil and Distributor??

 

Thanks again

Andy

[welshpug 1,626]

have you checked the Coolant temp sender yet? if it tries to start more when the afm is unplugged and you do have spark then it is screaming fuel issue, not ignition.

 

 

if you do wish to go to a wasted spark ignition system then you can i9ndeed retain most of the sensors and adapt the t/b or fit a gti6 inlet and use the gti6 throttle sensor, this is what Simes did on his initially with good gains and he used Emerald.

 

you will need a lambda boss for tuning but it's not necessary for normal running, you have to pay a fair bit for an ecu that can match the control of an o.e.m ecu's lambda control.

[DGTi 0]

Hi, yeah the CTS readings were there or thereabouts what they should be when cold and when warmed up... the mechanic did say he felt it was overfuelling, then went on to say his opinion was that the AFM is at fault, as other than the CTS this was the only other thing affecting the fuel mix?

 

I like the idea of wasted spark, as it seems to cut out a lot of the unreliable components that cause issues with Mi's which appeals to me, as when I eventually take the car home I am about 50 miles from friends and family, so if I have issues after taking it back it will be a real pita!!

 

That and the fact the Mechanic is saying if we go down the Megasquirt route he can better diagnose issues with the running. Due to the conversion wiring I had done by constella the car is far from standard in the wiring sense... the fuel pump is hardwired to the ignition and we can't find the diagnositcs plug that was on the loom when I gave the car to constella for example... so this added to old parts that I'm not sure are working correctly leaves me in a difficult position... I was ready for pulling the engine out and breaking the whole car at the end of saturday!!!

 

I also have concerns that the conversion to wasted spark wiill come with unexpected surprises and costs though, its looking like about £350 for the MS1 v3 ECU alone! I have already spent way more than I expected to on this Mi conversion, and I haven't even been able to take the car out for more than 5 miles yet which is very frustrating!! Starting to wonder weather I am throwing good money after bad...

 

What do you mean by: "you have to pay a fair bit for an ecu that can match the control of an o.e.m ecu's lambda control."

 

Do you mean using the lambda for normal running rather than just the set up??

 

Cheers

Andy

[S@m 156]

You are using thermal transfer paste on the back of the ignition amps, aren't you?

 

But as said, unplugging the afm having an effect does make it sound like a fuel issue.

Edited July 15, 2013 by Sam306

[DGTi 0]

Yeah I put Thermal paste on the amp before fitting, although I did note that the old one fitted by Constella was dry!!

 

I put my hand down after it cut out to see if the amp was excessively hot, but it was barely warm, and the heatsink behind was similar.

 

So any ideas on what could cause the fuelling issues then?