[engine_work] 2.1 S16 Build Diary

[Doof 11]

Welshpug, this combined switch? how is it different to a normal 8v sensor? You see, i bought a new 8v sensor which i'm using for the gauge, so presumably this isn't the switch. There's a spare green one and a brown one (AC i believe and ECU sensors) but no switches. They all look the same to me to be honest.

 

Electrical gremlins are a lack of indicators and a lack of driving lights. I've rubbed all the earth connections down, maybe the plugs themselves are corroded though so i'll attack that tomorrow.

[Doof 11]

Seems Ritchie-Van-GTi thinks otherwise with the coolant temp switch:

 

"Blue one is the coolant temp guage sensor, green is temp sensor for the ecu and brown is the switch for over temp"

[James_R 3]

Seems Ritchie-Van-GTi thinks otherwise with the coolant temp switch:

 

"Blue one is the coolant temp guage sensor, green is temp sensor for the ecu and brown is the switch for over temp"

 

 

Brown is the rad swtich. blue is the combined job, you can just put the 205 ones in place of the blue and brown. and then run the coolant fan off the rad swtich.

[welshpug 1,657]

yes, that's nearly exactly what I said earlier the blue one is also the switch for the coolant temperature warning light.

 

the brown one is the bitron sensor for the fan control unit on aircon equipped engines.

 

edit; beaten to it by James!

 

your electrical gremlins I would be 90% sure are the connectors, the 2 yellow ones for the spots (I chopped these out for some superseal ones having had the same issue) and the plug on the back of the indicator.

Edited March 25, 2009 by welshpug

[Doof 11]

Disaster!! I feel violent sick!!

 

The time came to start it today...thought i'd do a quick compression test...200psi on cylinders 2,3 and 4. Cylinder 1 is showing 0psi though! Where do i start? Do i start? Do i buy a new car? Get the shotgun out? Argh i feel ill!!

 

Could a bent valve really lose all compression? Surely i'd get something?

[DrSarty 90 1 Cars]

Without reading back, why do you suspect a bent valve? And also, did it try and start, as it would run on 3?

 

Feel for ya, but don't jump to conclusions just yet. Has it stuck long enough for a valve to be stuck open? Always a simple reason. You'll get there.

[Doof 11]

Without reading back, why do you suspect a bent valve? And also, did it try and start, as it would run on 3?

 

Feel for ya, but don't jump to conclusions just yet. Has it stuck long enough for a valve to be stuck open? Always a simple reason. You'll get there.

 

I just had a horrible feeling when i was putting the cams in and tightening them down that i had them placed such that the inlets and exhausts would tough together. Thing is, i checked them out afterwards and there were no visible problems. You really couldn't tell so i thought i was ok. I'm fairly sure it was that cylinder too.

 

I'd have thought i'd get some compression at least though? To get 0 psi something has to be seriously wrong i'd have thought.

 

Just took the rocker cover off and turned it over by hand, all valves look to be going up and down fine as far as i can see. Certainly the lifters are.

[Doof 11]

Interesting development. I was literally about to start taking the head off but then spoke to Mark (mad professor) who suggesting starting it to get any sticking valves moving! And after a pop and bang, i've just done another compression test and got about 190psi. i'm not convinced it's as high as the others but at least i dont have a hole in my pistons!!

 

Any thoughts on this? Sticking valve? Should i be concerned about a slightly lower compression value?

 

Just want to say a massive thanks to Mad Professor who has helped me out so much on this project. If anyone is thinking of using megasquirt, please please get in touch with this legend! If i don't have to take the head off, there's £50 coming your way as a thank you for suggesting this Mark!

[welshpug 1,657]

are you still on hydraulic lifters/tappets?

 

if you are it's quite likely that a couple were stuck closed.

[Doof 11]

It runs!!!!

 

Looks like something was sticking because I now have 190psi after trying to start it! I just ran it up to 2.5-3k rpm and it seems the base map provided by mad professor is good enough to run it at least!

 

Let the tuning commence!!!!!

[Miles 331 1 Cars]

Good new's, as said the std lifters need some use to get going and could well have been stuck and some RPM's have free'd them off, 190 PSI isn;t bad without everything bedded in yet

[DrSarty 90 1 Cars]

I could've sworn Lewis that's what I said might be the problem; the first reply after your plea for help. Where's my £50?

 

I have concluded that I speak, and type Swahili. What sounds like words coming out of my mouth, and looks like clear English on a page or screen, perhaps is just gobbledegook. Or as Baldrick says 'Gobblajook'.

 

This and the 9/11 thread has convinced me of this. Perhaps I owe you £50 Doof (?).

 

[Doof 11]

Ha ha, yea maybe thats unfair of me! He's helped me an awful lot though so he deserves it. I just didn't believe that a valve could stick to be honest. Mark more or less made me go and try to start it.

 

Ok enough excuses, i appreciate your help Sarty, your thread has been a huge help alone!

 

Best get the wheels on or something tonight. Will post back with a video or something soon.

[nick 3]

I thought it was a sticking lifter... but didn't bother writing it.... can I have £50 too?

 

Gonna have to pop over and have a look Doof, let me know when it's moving.

 

Nick

[Henry Yorke 269 3 Cars]

Great news Lewis. Looking forward to seeing this in the flesh at some point. We will have to arrange another Curborough day once it is run in nicely

[Doof 11]

Ok the megasquirt tuning has started this last week. Unfortunately when i came to bleed the brakes to take it outside though the bleed nipples were totally siezed which lead to me taking the rear beam off so that i could replace it with a 309 beam. Anyway, it turns out new beam mounts and brakes were needed so i'm waiting for yet more parts at the minute.

 

Anyway, back to the megaquirt tuning. At the minute it idles at 3000rpm and after 20 minutes with the idle valve out i've figured out the number of steps i'll hopefully need for idle. Or at least i've figured out what the step count means.

 

Basically the Magnetti Marelli 306 GTi-6 stepper motors appear to have 240 steps. To check that i set the retract value (oddly named "start value" in megatune) to a really high value (250) and kept increasing the cranking position til it was shut (at 240). Also, thinking about it, the wiring isn't as difficult as i thought. The centre two pins are coil A and the outer pins are coil B. If you were to find that the motor didn't move, you can just swap the inner pair or the outer pair and it should then work.

 

Hopefully i'll just be able to set a suitable cranking position for my stepper now and the closed loop idle will be able to control the idle sufficently.

 

I'll post back once my beam is on and the car is outside, then more tuning can be done and hopefully then i can drive the damn thing!

[Doof 11]

Ok, the tuning of megasquirt continues and christ is this a difficult thing to do! I just can't get it to idle very well. Anything less than 1300rpm will just not work. Something that is really getting to be is the wavering of the idle. It's running a linear curve on the idle valve so nothing is actually changing yet the rpm wavers by anything up to 300 rpm. I mean how can i possible begin to tune properly when the o2 value is all over the place and so is the RPM.

 

I'm seriously considering taking it to a garage, but with megasquirt, there are no bloody garages that know what MS actually is!! How i wish i had just taken my car to emerald and got them to install a system!!!!

 

How can my RPM waver when nothing is changing? Any 'squirters got any idea?

 

Thanks,

 

Lewis

[Doof 11]

Screenshot to show wavering of the idle! I really can't see what inputs can change this. Essentially you have 2 inputs, fuel and air. I know air isn't changing as i'm not pressing the throttle, so why is the fuel changing. It clearly is because the o2 is all over the place.

 

Edited May 24, 2009 by Doof

[DrSarty 90 1 Cars]

I feel for you Lewis.

 

I remember during my build some people quite literally saying "Don't bother with MegaSquirt...get something proper", i.e. Emerald, DTA, Omex, KMS etc.

 

Fundamentally there's nothing wrong with it; however the hassle you can have (and frustration it brings) when it doesn't work right means the extra cost - which is all it really boils down to - of doing it 'right' is definitely worth it. I'm testament to that.

 

Incidentally the ingredients you mention for idle - although you didn't say compression and spark - are the same all the way up the rev range.

 

I'm presuming you've tried some simple swaps such as:

* the sensors which tell the ECU what's going on (coolant temp/inlet air temp/MAP (poss), crank angle sensor, cam sensor (if you're running sequential) or AFM (if applicable)

* the injectors (maybe one's pulsing/fluctuating flow...or they all are)

* any ignition components (leads/coils/amps)

* ICV/IACV (cold start thingies)

 

All of these are rapid swaps if you have access to a known good item.

 

Do you have any leaks that as the engine rocks on idle opens & closes beyond any sensors?

 

Do you have sufficient, usable fuel?

 

This is the PITA fault finding process that not only I would go through, but the one which is often avoided with using a professional (and maybe professionally installed too) ECU, followed by a damn good mapping to boot.

 

You will get it sorted, and then you'll enjoy it.

Edited May 24, 2009 by DrSarty

[B1ack_Mi16 67]

It's not necessarily megasquirt's fault Sarty.

I know lots of cars using it which are behaving good.

 

What about trying to map the thing without the idle valve as a start?

 

And just set the throttle opening such that it will idle nice at your desired rpm value when engine is warm.

 

Then later on just use the idle valve as a cold start valve to give more air when cold (so it's 100% closed when warm).

 

Also a mate of me have had some problems with varying signal stability from some sensors and if that's the case you need to get that sorted first.

 

What about your O2 sensor, it is not a Innovate one is it? I have only had problems with mine so it's now 100% disabled and I'm running engine without it.

[Doof 11]

The idle valve is something i really dont trust, and megatune's terminology of what everything is is frankly rubbish so actually figuring out what you're changing is hard! Sometimes i seem to change the idle steps and it does what i'd expect, other times it just doesn't do anything. I just tried again and got a stable idle at 1300 rpm but with a map value of 45kpa and 12 to 1 AFR which is way rich. So i tried to lean it off in the VE table and took nearly lowered the values around the current idle site by around 50% of what it was and nothing actually changed?! Go figure.

 

Will go try again, thanks for the ideas guys, much appreciated when you feel totally helpless and in way over your head like i do now!

[taylorspug 7]

Id dump the idle valve personally, even from reading the Emerald book there is about 6 pages on getting one in and set up, so it must be a bit of a pig. My car idles perfectly at 7-800 rpm on Emerald, not an ICV in sight.

[James_R 3]

I'd agree with Dan, I'd dump the ICV you don't need one, Cam didn't run his, I guess if you have PAS, AC and so on it's handy, but you should get a rock solid idle without the valve.

 

I'd also expect the exhaust O2 to be all over the place at idle as the exhaust gas is sooo pulsed, can you dampen the reactivity to the O2 sensor to stop it trying to correct all the time? Or just dump it and do it by ear basically, or look at the narrow output and have it just above stoic.

 

Take a bit of tinkering but I'm sure you'll figure it out.

[Doof 11]

I can't tell you guys how good it is to actually have people throw ideas into this. Makes a change from knowledgeable people saying "definitely sure you've got enough oil in?"

 

About dumping the ICV? How can it then bleed extra air in to have a fast idle? You need a valve surely?

 

Might just try and get it idling warm and close the ICV off. My problem is i need an MOT before i can drive and i need the idle sorted so i can get an MOT. Catch 22 really.

 

Think i'm going to stick at it for a week or 2, after that i might ditch it and drop the car into Emerald!

[EdCherry 34 1 Cars]

could always set the throttle stop so it slightly open to idle, just an idea I dunno how you'd go about mapping it but it seems logical to me thats how youd do it.