Mi16 Fuelling

[jackherer 543]

After a lot of odd issues with my Mi16 I ripped the 1.3 loom out and fitted a 4.1 loom and ecu. It ran fine for about two miles then cut dead again.

 

This time it has spark and fuel but wont fire at all. The plugs are drenched so it looks like its overfuelling. I've tried the ECU temp sensor and AFM but they are OK, I put a new fuel pressure reg on and thats made no difference.

 

What else could affect fuelling?

 

Does anyone know which pins on the ECU connector are for the temp sensor? I'm not at home so don't have access to any of my diagrams etc.

[pugrallye 0]

lambda probe, coolant temp, airflow/temp and map conrol fuelling, delete as appropriate if not meant for your engine management

[jackherer 543]

I did a search and found that the temp sensor is pin 13, so I checked it with a meter and the resistance is the same at the ecu connector as the sensor itself so thats not it. Also buzzed through the wiring for the AFM and TPS.

 

Also tried another crank sensor.

 

I'm beginning to wonder if its not overfuelling at all, all the problems I've had started when I refuelled at a tesco petrol station, maybe the fuel is dodgy?

 

 

lambda probe, coolant temp, airflow/temp and map conrol fuelling, delete as appropriate if not meant for your engine management

 

I've tested the remaining stuff (I think...)

[pugrallye 0]

if your spark plugs are wet and your def getting spark then your definately over fuelling, have you tried starting it with the coolant sensor unplugged?

[jackherer 543]

yes I have, no change.

 

resistance of the temp sensor is almost the same as another (cold) Mi16 I have, and not too different from two other sensors I have out of engines.

 

I've also tried disconnecting the fuel pump to see if it has a burst of life as the fuel pressure goes down but it doesnt seem to and all other overfuelling Mi16s I've looked at have done.

[jackherer 543]

Am I totally crazy to think the fuel might be bad? I've changed every engine management component including ECU and loom and it still wont run...

[pugrallye 0]

does happen some petrol stations can get water in the tanks, and it reeally messes with cars. I had one once that i stuck 40 quid in and refused to start drained the tank, refilled with diff petrol and voila started on the button

[Guest 205_dave]

You can adjust the fueling by turning the screw on the AFM in and out, not sure if this is just idle mixture though.

[KRISKARRERA 2 1 Cars]

Yeah it's just the idle mixture.

[jackherer 543]

I had one once that i stuck 40 quid in and refused to start drained the tank, refilled with diff petrol and voila started on the button

 

was it immediate or did you get down the road first? mine literally wouldn't start after a couple of coughs while it was still by the pump. I then pushed it to the car park and started messing with relays and stuff which I think caused some wiring faults that I've been stuck fixing for the last week!

 

 

You can adjust the fueling by turning the screw on the AFM in and out, not sure if this is just idle mixture though.

 

technically you can adjust the mixture through the rev range by messing with the spring in the AFM but thats not going to fix my problem, my AFM works on other engines fine.

 

 

I am going to park it next to another pug tomorrow and run a long fuel hose across then bridge the relay so it supplies fuel to mine. If this works I guess I'll have to drain the tank and then drive to tesco for an argument

[pugrallye 0]

no it was pretty much immediate (granted tank was empty) couldnt pull away at forecourt

[pug_ham 240 3 Cars]

Is it a good strong spark you are getting or simply a spark? I had this on my white GTi a few years ago after I came back froma holiday & everything seemed to be working but it simply wouldn't start.

 

Turned out there was damp that was dulling the spark so even at first test I had a spark it wasn't strong enough to allow it to fire.

 

Graham.

[nick 3]

Are the plug threads clean and the plug holes free from oil etc...?

 

I had a similar thing on a bike once when I greased the threads on the plugs a bit too much, had a great spark with the plug earthed on the cylinder head but when I put the plug in the hole the grease was insulating it and stopping the spark.

 

Also when the plug holes filled with water on the Mi the plug was just arcing across to the head and caused a really bad misfire.

 

Just a couple of ideas...

 

Nick

[jackherer 543]

Graham: the spark is strong, its got a brand new cap+arm on too.

 

Nick: I've got three sets of plugs I've been testing with, same thing with all of them. I'll try to clean the threads in the head (no idea how though). I've had water down the plugholes on an Mi before after driving through a ford, I had aftermarket leads and no spark plug cover fitted back then so they were particularly vulnerable.

 

Thanks for the suggestions, I suppose I had better go and work on the bloody thing some more... I flattened TWO fully charged batteries yesterday trying to sort it out!

[sorr 0]

I would check the loom from the ECU to AFM. The only time I have had massive overfuelling and a refusal to start was when a wire in the AFM connection had snapped.

 

See this thread for more info.

 

Over Fuelling Issue

 

Hope this helps as it took me a week of investigation before I damn well found it when my car had the same symptoms.

[jackherer 543]

I've swapped the ECU and loom already, and I buzzed through the wiring on the new loom for the temp sensor, afm and tps.

 

I've wired up 20+ Mi16s and fixed probably 50+ for members on here over six or seven years and this one is really starting to do my head in. It was just a couple of months ago that a friends Mi16 had exactly the problem yours had as it happens, it was a bit of a headscratcher for me but only for maybe one afternoon, not well over a week like I have taken on my own car so far Ive got a lot of spares and access to lots of running Mi16s so I am normally able to track these things down pretty quickly and without having to post on here, normally I post fixes in these sort of threads

 

Hopefully alternative fuel will be the answer, if not then I cant think of anything else to try

[James_m 0]

Timing belt slipped a tooth whilst cranking on the starter?

[Dream Weaver 2]

These niggles are so annoying - when it happened on mine new plugs sorted it, but doubt that is the issue here.

 

If you have spark, fuel, air and compression and the ECU is reading everything then it MUST be the fuel that's in there causing the issue, but tbh i've never experienced problems with fuel in 15 years of driving.

 

Only other things are dizzy cap and ign module that I can think of.

Edited August 10, 2006 by Dream Weaver

[nick 3]

As above, I have been driving 21 years and have never had a problem with the fuel itself, but you never know!!

 

Keep us updated.

 

Nick

[jackherer 543]

Timing belt slipped a tooth whilst cranking on the starter?

 

it crossed my mind, but it has run ok a couple of times and its got 200psi compression across the board.

 

 

Only other things are dizzy cap and ign module that I can think of.

 

I've tried several that worked on other cars, the cap and arm on there now are both brand new.

 

 

I haven't been able to work out a way to get another car next to it so haven't been able to try new fuel yet.

 

However I decided to pump some fuel out and I got a pint of YELLOW liquid, properly bright yellow like piss

[pug_ham 240 3 Cars]

However I decided to pump some fuel out and I got a pint of YELLOW liquid, properly bright yellow like piss

Does it smell like petrol?

 

Put a match to it & see what happens.

 

Graham.

[Rippthrough 98]

Does it smell like petrol?

 

Put a match to it & see what happens.

 

Graham.

 

 

Tried taking the fuel pump fuse out and useing a bit of ez start?

[jackherer 543]

I just pumped some out of the cti and its about the same colour, maybe slightly lime green but def has a yellow tinge. But it seems to smell MUCH more like petrol than the stuff in my car.

 

ez start is prob a good idea, I'll go get some.

[KRISKARRERA 2 1 Cars]

However I decided to pump some fuel out and I got a pint of YELLOW liquid, properly bright yellow like piss

That's just normal though. Unless of course someone had urinated in your fuel tank at some point.

[Dream Weaver 2]

Any news on this?