OMP

Hi all.
It's been a while, but I am back with an (almost) finished product....
My 200 MC1 automatic is back on the road for a few months with a new installed gearbox that is working perfectly ( after 3 boxes in the past 3 years).
So, after redone the engine ( about a year ago), and the new box, finally I have a good,solid, daily driver, with the last ( I hope) problem.

Now this issue I have commented in the past ( I think), but cannot have an idea.

Basically, If a hammer the throttle, the car will pull from stop extremely well, but once it goes over 3500 rpm, it's like there is no more rpms to look after....The engine will increase its rpm and gain speed, but very slowly compared with what I recall the car running new.

Also, up in the 3500-4000 rpms, very little vibrations are felt in the engine...It seems that the car is not "comfortable". The car will not buck or anything, is just that it is a bit rough ( not the sweet, vibration free feel so typical in these engines)...RPMs will continue to build, but is just hard.....
Without being 100% sure, but it is like the timing would not advance as it should, but this is just as idea as I have to experience a retarding timing knowing that is retarded....I just don't know if it's that.
Pulled codes a few months back and no errors.
All temperature sensors are either new, or tested ( most of them are new).
New everything, plugs, fuel filter, fuel pump, pressure accumulator, fuel injector rings, etc....

I have a qlcc ECU but the car won't start with it, so I am guessing the ECU is not working. I do have a spare stock MAC-11 ECU that I might try these days, but I am very positive that is not the ECU.....as the car starts perfectly, idle extremely well, not bucking, no hesitation, etc....boost will come soon to 1.4, so ECU seems to do it's job.

I can't think of anything....It is really a shame because the car works very well at lower speed, but once in the 4000 rpm area, it will just struggle...Again, it doesn't buck or misfire or anything, is just that it will have a hard time building rpms.....If I keep the foot down, it will go up in the rpms but again, very slowly and kind of slightly rough....but not violent....just not the vibration-free feel.

This is why I am pointing at:
- either something wrong with the knock sensor ( Really i don't know what) - it was replaced by a new, original one a few years back. But still, what could be wrong if the car runs?
- Something with the ECU....Any ideas what could be?

Thanks

MarkPan

distributor could be out of alignment... or fuel pump dying? eventually that gets so bad you can't get over 2k, and then it dies...

how is the boost? could be blowing out a hole (michelin man hose would be first to check), then running too rich.


One time I had a gutless 5k... linkage was getting stuck on the hoseclamp for the michelin man hose, and couldn't get over 1/2 - 2/3 throttle.. lmao.

OMP

Hi
I can get the throttle all the way down, no issues there.
No vacuum leaks, all hoses are new except for the Intercooler one ( not the Michelin man hose, the other) but it has been tested and no leaks either.

All timing is dead on with new spark plugs and recent distributor. New wires also.
New fuel pump, new pressure accumulator ( although fuel pump does make some noise - but I think is "normal").

However, fuel pump relay is original on car ( 23 years old), but if it was a faulty fuel, in my head I would have many other issues....don't you think? Like no running condition, or random shut off....I don't know...

Keep looking for ideas...

5000CDQturbo

here is an idea, you said it has an automatic trans, correct? Have you thought of the sensor that is on the driver’s side of the trans ... these do go and cause some strange symptoms at higher rpm. dave