hy well at first her is my configuration after a engine rebuild:

piper cam 285
mongoose exhaust
bailey dump valve
bailey oil breather
new stage 2 t3 turbo

7200 rpm rev limit (black box)
turbosystem ecu chip (appartly a no limit)

i set my boost on 1.4-1.5 BAR 20-21 PSI

i put my AFR on idle 14.7 and when i drive the car my afr is at 11.11 also on boost (after setting the black fuel pressure box on the meetering unit )
the car runs fine

but i have a BUG or like little missfire when i am in the 3 gear puch full throttle and at 4000 rpm it sound likee BRRRRRRRRRRR i hear the sound in the end exhaust pipe and the boost drop
only when i throttle very slowly it looks fine
...

can it be that my ignition timming is not good need to put it 12 degree before pmh no?

i also saw that my 2 green O-rings seal on the pressure black box on the meeering unit are done because i have a little fuel leak on it need to replace this 2 o rings

thank you

 

What intercooler do you have??

Try running no more that 18psi, maybe your injectors are running lean, I cant remember how much boost you can run before needing a 5th injector, are you still MFI??

 

big airtec intercooler yes still MFI but i set up the fuel pressure to have a good AFR velue on boost

 

Well thanks to all for sharing it.

 

It could be detonation, but I've no had the boost drop before.
Set your timing to 8 degree's BTDC and see what happens.
What actuator do you have, it could be creeping open, perhaps try a little more preload.

Fuelling is a little rich but wouldn't cause this issue.

 

i have a -31 acutator the turbo is brand new ..

the turbo is starting to load at 2700 rpm...


when i set the timing i let the car on idle an then disconnect the vacumm hoose to the ecu i don t need to close this vacumm line because i gonna do a air leak no? and then set it to 8 degree ?

 

Yes close the vacuum line.

 

ok i will try thanks and only one questin why not 12 degree like standard setup?

 

Because you may be experiences detonation and so by pulling the base timing back 4 degree's you'll see if it cures it or not.

 

ok well i put iit like 8 degrees an is fine no any boost bug at 4000rpm

but i also put my fuel pressure back because i had to mutch pressure that at the black box on the meetering unit i had a fuel leak
now it s ok no any more leaking

but now i have only 12.3-12.4 on AFR when i drive it also on boost it s 12.3 some times it hit the 11.00

before i always had 10.5 -11.11

is it enough safly with 1.4 bar turbo boost ?

 

If it were EFI and you had some form of detonation monitoring then yes, but on ropey old MFI that's a little lean and your taking a risk IMO.

 

In a nut shell no, it's why I hate mfi so much, it gets to a point when trying to get to much power that you end up running it abit rich low down to make it safe on boost


It was a good idea when the car was new but now it's just crap, aftermarket management is the best mod on a escort even at lower power levels

 

hmm well i gonna make it a little bit more pressure on the black box i know mfi is old i start to hate it lol

 

Whats spark plugs are you using and whats the plug gap?

Rob,

 

ngk bcr8es is 12.3 on afr with 20 psi realy to lean rob ?

 

Yes, should be closer to 11. Below 11.5.

Karlos's suggestion was a very sensible one. Retard the timing to see if that helps. However this will also reduce cylinder pressure which may hide a spark plug related issues. What is your plug gap?

When the noise happens does the engine misfire violently? If not then I suspect you are hearing detonation. For you to hear it at all with no det cans means its fairly severe.

Lean plus possibly too much advance is a recipe for detonation. Buy some det cans!



Rob,

 

yes ok the gap is like standard 0.7mm i didn t toutch them


before a had 11 11.5 on afr but my timingwas not set can t remeber where it was

then i took the fuel pressure down to 12.3 on afr because the black pressure box on the meetering was leaking fuel with 11.5 afr i also change the 2 gasket rings
and i set my timing on 8 degree and no any problem the car runs fine know but 12.3 AFR is not savely need to put it back to 11 -11.5 because im at 20 psi

before i realy hear noise at 4000rpm in the end on the exhaust when it was boosting.... and the engine bugs dreeeeeeeee but i think when i push the throttle gaz slowly it was fine .

but i really think it was the timing setup because the car drive very more fine know and better but it s also because is leaner lean-more perfomence but not savely..

well whats about the gap is this important?

 

well i put it back to 11 - 11.8 when im on throttle but still the problem if im at 2000 rpm at 4 gear and low speed and push the gaz pedale full down its lean like 18 on afr and than slowly goes to 14 .13.12.. on boost

and also if i direct push the gaz pedal down i have some misfire at high rpm

i always to push slowly down the pedal too have a goood result

and i have again a little fuel leak at the black box on the meetering unit when i puch it back to 11-11.5 on AFR before i had 12.3 AFR and no leak

what i don t understand is do i every time need 11-11.5 AFR on driving normal ( it s ok ) but when it boost i think is impossible to have 11.5 it every time stall a little bit to 12.5 -13.5 AFR when the car is boosting like full throttle on 1 gear...?

i know is the old ke jetronic

 

To be totally honest with you it sounds like you should be looking at efi. Your MFI seems to have caused you so many problems

 

I'd be doing one of 2 things...
Taking it to a pro to get it set-up so you know its safe as you are going to kill something in your engine soon

or

Swap it to efi and fine tune it all yourself with a standalone ecu, like ofam

 

turn the boost down till you can have it setup right and drive it off boost until you know its set up safely. I bring the boost back to 1 bar and see what its like. id still refrain from driving hard/on boost tho until your 100% it fuelling right

 

yes i know but to turn to efi it s a lot of job also to find all the parts who i need burton need to do a efi kit or something


well i gonne drop my boost..

 

inbox karlog g about aftermarket efi...

 

well i go take my turbo pressure from 20 to 18 psi at will look to do set up again my fuel to 11-11.5 on AFR
but whats again with the spark plug gap? i have the NGK bcr9es it think the gap is 0.7mm no ?

 

I have a simular problem on mine with the strange sound comming of the engine. Only happing when you hit the pedal completly. I have it in different gears, but it always starts after a gear change when i hit the pedal.

When i keep my foot down the sound stays, rpm stay exact the same. When take foot up and down sometimes it goes again sometimes i need to hit it slower and it goes.

Does this match your problem? or your is different

 

sounds like det to me mate

 

Isn't there a bigger chance its retarding for some stupid reason?

Anyway i need a recalibration anyway so it might dissapear then

 

yes it was the ignition had it before at 12 degree and now at 8 and it s still better

but my ke jetronic is strange i have know a AFR 11.7 but when it boosting it goes up to 12.7 impossible to stay at 11.7 also if i am in the 5 gear at only 50kmh and i push the gaz pedal directly down it hit s the 18 on afr what is normal but teh goes back to 12.3 AFR when the engine goes up in rpm

but also at idle the afr goes from 13.9 -14.2 to 14.7 i but the idle is stable

ke jetonic is not the best but is ok i want to go back on a dyno to watch how mutch power i have ...

 

Timeing

 

Think your KE tronic is running on its max. I ran 210 bhp with 0.9 bar of boost. Isn't your situation maybe the max for MFI?

 

yes it s maybe the max