OMP

Hi.
Since the overhaul the car does not go over 3500 in 1sr speed ( Audi 200 turbo automatic). There are no vaccum leaks and sensors and hoses are perfect. New plug wires, everything....
Thing is car has a cold and hot start issue ( car starts really bad cold or hot). Once running, it idles perfect and runs good. However, now that I'm beginning to push it a little bit ( after the engine overhaul complete with piston rings), I realize that the car, althought showing 1.3 bar on the computer, it won't go past 3500 approx....No fuel cut-off, no bucking, no nothing, it just does not go over that figure.

When stopping the car, it smells badly to gas.....Could it be a bad working fuel pressure accumulator or fuel pump? It's the only thing that comes to my head...Is it logical, or really has nothing to do with that....

Why would this happens. Car has almost everything new ( fuel pressure accumulator is original on car as is the fuel pump - 145000 milles).
Coudl it be that CO mixture has not been set correctly? Am I missing fuel in the engine.
MPG after the rebuilt is extremely low, but the car runs pretty good ( except for the acceleration part), once moving on the higway....It is on pure acceleration that it does not beyong 3500 rpms.

Any ideas? Where to look for?

Thanks

gedis080

I would start from fuel pump, then fuel pressure regulator (not accumulator) and then lambda probe.

Kneale Brownson

You have fuel but you do not know whether you have sufficient fuel pressure.

Inadequate fuel supply and loss of residual pressure when not running could explain hard starts and limited performance.

OMP

Thanks.

I have bought a new fuel pressure accumulator ( the one in the back ) and a new fuel pump, which I will install probably next week.

Another strange thing. Testing the output of the engine, there is NO WAY the car goes beyond 1.3 bar on the clock. No matter how hard I smash the pedal, it will go at about 3500 rpm's and turbo pressure up to 1.3 only....And I say only because hte car has a KG engine Wastgate with a 1.8 bar spring ( standard for KG ) in it.....

So, if I had limited fuel pressure, wouldn't the car buck or cut fuel...Or just the there is no enough flow to go further into the rpm's??

Another thing is the nasty fuel smell when stoppng the car at the back right side ( where the accumulator is).....

Could all be related? Not enought fuel supply?

Kneale Brownson

Insufficient fuel pressure definitely will influence performance. The new pump may solve all your problems.

OMP

Catching up with the subject.
I finally got the fuel accumulator (new) and new fuel pump installed.
Now the car will start inmediatly with no issues.
Have not had time enough to do a complete diagnosis, but it is definetely starting a lot better. The only issue is that, even if it starts right away, at about 30 seconds from starting, the idle will go very low, and the car will almost die ( it idles at approx 400-500 rpm). Sometimes it will choke, but no always. Once warmed up ( 2-3 minutes ), the idle wil stick to a solid, 800 rpm with no hesitation.
However, my 3500 rpms issue continues.
When pushing the car in first gear ( auto 3-spd ), the car starts very nice, gets a little turbo kick-in ( at about 2700 rpm), but it still tops out at around 3500 rpm. This will happen on 1st gear when pushing the pedal all the way down. In 2nd and 3rd ( once into the higway), it will go beyond that mark, but it is definetely sloooow. It lacks the punch of the (almost), free-reving sensation that these car have over 3500 rpm. I would say the car has to work much harder to gain speed.
Bu as told, no bucking nor nothing, it just doesn't build up speed as it should.
At the time the car gets to 3500 rpm, the turbo gauge is showing 1.4 bar on the clock ( I have a KG waste gate which has a 1.8 spring). I don't think the waste gate here is to blame, as it will hit fuel cut-off if more air was to get into the engine....Any thoughts on this?

The entire engine is almost new ( rebuit 100%), and fuel system is checked, and rechecked. Also, new spark plugs, plug wires, etc...

Going thru SJM's pages, I have read about fuel pressure regulation. It details the regulator for the MC-2 engine, but does not go into detail in the MC-1, since it seems there are differences on the way the two engines build that fuel pressure.

I have also read about adding up washers on i-don't-know-what valve around the fuel pressure regulator ( up-front).

Any ideas on this ( I hope last ) issue for my 100% restored Audi 200?


BTW: I am installing bilstein B6's this week and got the cruise control working again, except that the day after, my speedo stopped working....

Regards

Nuttynotty

Hi OMP,
Have been following your problems,and was wondering how you are getting along, did you figgure it out?

Cheers

ledzepp2994

just a thought is it possible you got fuel and air is your issue? I had similar problems on a 4k and after replacing the whole fuel system im now chasing air intake problems.. just some food for though.

audi_marv

Try cleaning your Idle Stabilizer Valve, or adjusting Idle Screw at front of throttle body to eliminate low idle at start-up. Still may be a vacuum issue, or a Throttle Switch problem.

Fuel Pressure Regulator on MC-1 is located inside 13mm nut on front of fuel distributor. Its a spring loaded needle valve, with several washer shims, and 3 o-rings. Probably the o-rings have failed, or dissolved. Adding a like size shim, should increase fuel pressure by about 3psi.
The whole needle valve unit can be bought at autohaus for about $40.

Sounds to me like you have a 1 bad plug or 1 bad wire, or a clogged injector. Try a can or two of seafoam or techron, and check plugs and plug wires for a defective one. Just because they are new doesn't mean one isnt a lemon.

OMP

Hi.
Thanks for the answers.
The car has been finetuned this week. I installed Bilsteins B6's ( what a difference!!!!), and the issue has been partly soften but not solved.

It stills struggles when going up in the revs.
From start, it is very powerful, but what I am looking for is that push from 3000 rpm's....Specially in 3rd.
I think the issue is not plugs or cable related, all 5 cylinders seem to work fine and there is only slight misfiring at idle, but nothing mayor. Plugs and cables are new, as I informed.
On another hand, what is p**** me off related to this issue, is the fact that turbo boost tops at 1.4, when the WG comes from an european KG engine Audi 200, which has a 1.8 spring WG.....Now I am gong to check if the WGFV tubing is correct, as it is dificult to someone who doesn't have an extended experience on these cars to switch the low/high pressure routing on it.
I also have an stage 1 from QLCC for 1.9 bar not yet installed, but want to wait and solve he "normal" engine behavior prior to do the ecu switch.

On another hand, I can't seem to find the fuel pressure regulator on the autohaus page. I believe is in the "fuel and air system" chapter, but don't find it....Only thing close to it is what they call "fuel pressure damper", but it is around 100plus $ and it is a Bosch PN. Actually, there are 2 Bosch PN's, but don't know if its that part you are talking about.

I am going to take the car for a spin and tel you more about it.
Many thanks