Peugeot 1.9 8V GTi - setting up the modified engine

[Guy Croft]

Damir, hi

stochiometric - chemically correct is 14.5/1 A/F ratio, Lambda = 1.

The engine - when tuned - will only be OK at 14.5/1 at idle, under load it needs to be richer. It is a fact that for best power you need to be rich of Lambda.
You need 0.87-0.88 Lambda at part load dropping to 0.85-0.86 Lambda at full load, so judging by your voltages, if I have read it right, your engine is going increasingly lean.

GC

[DamirGTI]

Hi Guy !

Ok. , then i will order adjustable fuel pressure regulator and try with increasing the pressure first until i found some good weber carbs .

Thanks !
Damir

[NickRP]

Damir

Have your chip read and send the binary to me. I'll check if I have something that might help you.

Best regards,
Nikola

[DamirGTI]

Hi Nikola !

You need chip code from my ECU or ? sorry i don't understand if you can explane a little bit more !

About ECU i have one spare and my mate is working on this (just for experiment ) :
link - http://www.205gtidrivers.com/articles/e ... chips.html

Thanks
Damir

[NickRP]

Damir, does you ecu have an EPROM chip? If it does, you need to find someone who can read it and email the contents to me.

Nikola

[DamirGTI]

Hi !

I really don't know if it has EPROM chip , but i will check that !

Thanks
Damir

[Guy Croft]

Nik, Damir, and anyone else who can help here - hi

for the benefit of other readers can you please try and spare the time to publish actual annotated pictures of these things. ECU (electronic control unit - controls ignition and fuelling) Eprom (electronically programmable read-only memory) etc. Some readers, for sure, will have no idea what these are or where they are located on this car.

Please - a good photo series is needed:

- Engine bay showing location of ecu
- Closeup of ecu 'this is the 205GTi ecu'
- ecu dissassembled and view of eprom (if I got that right)' this is the eprom'
- getting the eprom out 'this is how to remove it' etc
- anything else relevant.

Without this you might as well discuss off-forum, but hopefully you'll devote time to putting it here so other non-experts can follow step by step.

Thanks,
GC

[DamirGTI]

Hi Guy !

Ok. no problem i will post some pictures !

Damir

[DamirGTI]

Hi !

This ECU dosn't have the EPROM chip , i must look inside my spare ECU maybe its different than this one .

pisc :

[Guy Croft]

MODEL POST!

Well done Damir! You made a first class job of that feature.

Nik - maybe over to you for the next step?

I am kind of hoping this engine calibration can be sorted without recourse to carbs but it all seems to be a rather er, protracted and uncertain affair. It would be nice to see the issue resolved quickly one way or the other and the solution on show here. In other words, this inj system can be modified in a professionla and robust manner (and this is how it's done) or it cannot.

(Readers, if you don't know by now I will say it again - the recal of fully mapped engine after tuning (porting/cams) as being the biggest tuning 'headache' around these days). This website is useless if it cannot display SOLUTIONS.

GC

[NickRP]

Hello Damir, Guy

Damir, thank you for the excellent photos. I can't help you, this control unit is very old, and it requires hardware mods to be remapped (and I can't tell how fine or coarse the adjustment would be).

Guy, mapping itself is not THAT complicated, even for hobbyists with limited budget. Using simple and inexpensive wideband lambda unit, fueling can be optimized better than it would be possible using any carb. I don't know where in Croatia is Damir, but I have friends / customers there that would help him with mapping - for sure.

So Damir, in the case you are considering mappable injection, you are not alone in Croatia, there are people I know that could advise you accurately on costs and effort you would be facing locally. I could also help you by describing mapping for beginners in your language.

In case you decide to use carbs, help is also available - locally or online.

Best regards,
Nikola

[DamirGTI]

Hi Nikola !

Thanks a lot for that and i will contact you via PM .

Damir

[DamirGTI]

Hi Guy !

I have some news regarding this engine set-up job !

Before few weeks ago i have fit FSE power boost valve but unfortunately i don't have the fuel pressure tester and I¢ž¢ve been all around asking for this tester at the local mechanic workshops but nobody has it so i can't measure exact pressure , anyway i adjust this pressure valve "by feel" approximately one and a half turn from factory settings and it seems ok. (i leave it like this until i buy this pressure tester), I¢ž¢ve also fit a modified ECU (as you can see in the pictures) this helps a bit also it has two resistors soldered in the idle and off idle circuit , one resistor is for adjusting idle mixture and another is for off idle mixture adjustment . OE ECU have 1200Ohms resistance in the off idle circuit and I¢ž¢ve set this to 2500Ohms on my modified ECU , I¢ž¢ve try all combinations from 1200Ohms to 4000Ohms (you can set 9000Ohms maxi. !) and found that around 2000-2500 is the best . Idle mixture on OE ECU is setted a bit rich and I¢ž¢ve set this to almost fully clockwise on this another adjustable resistor - lean and it fells good on idle no stalling or choking .
Also I¢ž¢ve fit another AFM (Air Flow Meter) which was properly adjusted on rolling road and i have found some bigger injectors in my garage !
OE injectors fitted to my engine was Bosch 0280150702 with 189.2cc flow and I¢ž¢ve fit 0280150762 injectors with 213.9cc flow which was cleaned and checked with the ultrasonic cleaning device .
I didn't touch the ignition timing (no pinking or what so ever seems good !) .

Anyway car feels so much faster now pulling really hard in every gear from lower medium and high revs no matter its always the same force when i apply throttle !!
And i have some different readings from lambda sensors :
Idle - around 0.88mv
Throttle part open - 0-79 to 0.81mv
Mid range - around 0.84mv
Full throttle - 0.87 to 0.88 sometimes when i press harder it's 0.89-0.90mv
so i think that this is ok. now ? is it ?
Its still a bit rich on the idle , I¢ž¢ve try adjusting mixture screw on the AFM but this 0.88mv on idle doesn¢ž¢t change down ?!
Is it possible to risen the mixture just on WOT separately from mid range and idle mixture ?

Thanks all for advices and help regarding this problem you are most kind people !
Damir

[petert]

So it had the wrong injectors then! Those mixtures sound perfect now, including idle.

[DamirGTI]

Hi Peter !

Well i have two types of yellow injectors ( both from 1.9 8v engines ) this 702 injectors are from my spare head ( i've bought head togheader with inlet mainfold fuel rail and this 702 injectors fitted unfortunatly i don't know the type and year of 1.9 engine from which is this spare head ) , and this 762 injectors are from my old 1.9 8v D6B engine (1987 year) .
I didn't notice the difference in between them (they are both yellow colour so i was thinking that they are the same type and flow ) and i have fit this 702 injectors on my reconditioned engine few months ago .

Strange i didn't know that Peugeot used two types of injectors on 1.9 8v engines ?! maybe earlier models have 762 injectors and later 702 ..

Damir