Any updates? I hope you found the problem and the solution.

 

No. Havent done anything yet.
Fellow 55er tells me my problem looks like fuel problem, maybe my fuel rail pressure isnt what it should be. I have looped rail so i could easily reverse that and see what it does.

 

how are your AFR's
Over the past 2 months i had an issue of loss of power. On the dyno my AFR was falling to 10.3.
It turned out that the fuel pump was faulty causing over fueling. New pump and the car seems to be running much better.
Just a thought... even though in your dyno graph picture it shows 16.3??

 

Afr is pretty rich. But there again, i was testing on a dyno with pretty ****ty ventilation with 30c ambient temp.
My afrs have always been rich. But had the power nevertheless.
When looping the rail, do people upgrade the pump??

 

what AFR is ok on 98oct?


still waiting for a remap after logging on LM2 with AFR at 10

 

Higher octane will help with detonation
It depends on the timing your tuner is commanding

 

Did a co2 test. It was positive. Disasembling the engine next week to look inside. How much could i shave of the head and possible the block too?

I dnt wanna touch the block but i m told as its aluminium it would have deformed on the surface as well.

 

Where was the leak coming from?

 

Not sure yet. Hoping its the gasket or the head. Hope cylinders and rings are fine, but i didnt have detonation or rough idle to be thinking of pistons or cylinder walls. We ll see on monday i guess. But it makes me think, if the car still ran so smooth, could so much boost be lost coz of that or is it just coincidense ?...

 

Like I said you had a leak so now find where it is, could be rings or anything else. At least now you also know that your intake was no good since when you took it off you gained over 1psi

 

Fair enough. We ll see on monday.
Keep u posted

 

Removed heads. Found burn marks on the gasket and head from overheating. Cylinder walls, psitons etc are looking good. 2 valves on one side werent fully closed. Leaving the block be. How much could shave of the heads?

 

That's something to ask those who have actually done it

 

So. Finally we finished the motor
Shaved heads by 0.28mm
Cleaned everything. Regapped valves to open 1mm extra.
Hit the road.
Boost hit 16-17 psi with 77mm clutched and bwk. Got headers and tb to cancel each other out. Boost seems high though.

 

Good. Did you use the stock head studs?

 

Yes. Limited budget.

 

Put money aside you will probably lift again

 

Nice work and Good gawd, thats a lot of boost! Glad you got it fixed, it makes sense you should really stay off the boost until you get some head studs so you don't have to do this job again and possibly mess something else up.

 

Dynoed the car.
430-400 whp
730-700wnm
Its far slower than before when i hd 512whp and 500wnm.

I have no idea whats going on. Boost flactuates 16-14psi on runs. Iats hit max of 50c. Timing goes from -8 to -20 during the pull. Afr is fine up untill 3800 rpm aftar which it falls feom 12.2 all the way to 10.2, drastically and stays like that till the end if the run.
After dyno, STAR read timing chain off.
We fixed that and went back to dyno, results unchained and now star wont says ****.
I really dnt know what to look for. Thinking spark plugs, as car has 160k km and not sure if previous owner changed them, they still got mb sign on them. But timing are nt running around during the pull. Maybe inshould go 1 step colder. Idk.
In any way i really should not be seing 16.5 psi on just 77mm sc pulley.
Also, i get occasioanl misfire and cel when driving slow in town, saying its either map/circuit/or barometrecit unit.
Maybe the ecu is ****ed. We cleaned the map and wiring yesterday. Since then just got the problem once, and had a few runs on the dyno too.
Got looped rail. Any chance that ****in up something?
Also. We wrote a new tune leaning out 3800-7000 rpm. Afr came up to about 11.5 min but hp/tq stayed as they were.
Any input would be great.

 

Bro you have original plugs on the car and pushing 16psi?? You are asking for trouble. Do a compression test and if all good change to one step colder ngk LFR7AIX #2309 plugs.

 

Concider them ordered.

U think thats my prob?

 

Won't know til you change them but bad idea to be having 16psi of boost with old stock plugs. Lots of heat is being generated.
Do a compression test while you are changing the plugs
You want to do each cylinder to make sure that they are all close of each other.

 

Will do.
Whats a good site to order them from? I dnt want ebay and amazon.

 

It's amazing what a fresh set of plugs will do on a=an engine with very old/beat plugs !!

 

Rock auto