Dikiz

Hello,
mY car (MC1 engine) can`t start no mater is it cold or hot,even after 5-10sec after runing it`s impossible to start.If you tow it-it starts after few meters.
I i wish to start i have to put fuse ir fuel pump relay and pull for 2 seconds air plate and then starts.
When starts everything is ok no problem at all. I changed almost everything under the hood...
fuel distributor(3),air plate,warm up regulator,fuel pump(3)
One strange or not thing is that when fuel pump works(engine not runing) no fuel flows from fuel distributor to injector lines...is this normal or not?And how to fix it...?
ANy ideas welcome,because it`s very annoying to start car like mentioned above...
Thanks

audi_marv

Sounds like a fuel pressure or vacuum leak problem. When you put the fuse in the fuel pump relay, you are actually pressurizing the system. By pulling up on the air plate, you are letting fuel into the injector lines.

Reason for loss of fuel in the injector lines may be leaks in the o-rings and/or cracked plastic air caps at your fuel injectors.

Check for vacuum loss at the rubber air plate cover, rubber hose at intercooler, and all other vacuum lines.

Bad fuel pressure regulator may also be a problem.

Not sure, but i think fuel only flows to injectors when engine turns over/is running...as a crash safety precaution.

good source of info is: www.sjmautotechnik.com/trouble_shooting

ledzepp2994

I agree a leak of some sort, smell around, if you smell gas then thats most likely where its coming from. also when was the fuel filter last replaced? sounds simple but it makes a difference, you should be able to blow through it,

Dikiz

thanks for ideas,but i changed fuel filter too,fuel distributor,warmup regulator,fuel pump,fuel injector bought new 2-3 years ago.Before that problem the car sometimes worked ok,sometimes not,and now it`s impossible to start,without lifting air palte.
I have aftermarket boost gauge on idle it show -8 or smth,so there is a huge vacuum,maybe so small leaks causes that problem?
I don`t remeber waht force needed to lift air plate before problem, but now i need to much force i think.
I tried to add additional shim in the fuel distributor pressure valve or remove all,on driving i feel big difernce,but on starting no changes at all.
It pulls hard,easily can reach 220km/h or more.

Dikiz

and forgot to say no matter how long i crank no fuel goes from injector lines.
Maybe
Yes and i drive that car daily,so every time i have to go under the hood to start it,pretty stupid

audi_marv

Vacuum is what lifts airbox plunger lever, which allows fuel to pass thru slits in your fuel dizz to your injector lines. Either you are low on vacuum (leaks), or your air plate/plunger is stuck or out of adjustment.

Try removing the air plate rubber boot, and clean with throttle body cleaner. Check boot for leaks, and make sure it is tightly secured.
Also check hose connection at back of airbox, and idle stabilizer hoses.

After starting car, remove the oil cap. Car should stall if you have no vacuum leaks.

Did you replace fuel dizz with new, rebuilt, or used ? Rebuilt dizzys often have gasket leaks. Were the injector O-rings and caps also replaced?

What model and year is your car ???

A can of Starter Spray is another option to get the car to start. No more than 3 squirts in the air boot plug hole (if there is one), or at the throttle plate.

Bad fuel pressure regulator still a possibility, as its not holding a high enough fuel pressure after shutoff for easy restarts.

Dikiz

i replaced 3 used fuel distributors and 2 air plates used too.Everything the same.
Fuel injectors and o rings are new.
I suspected too vacuum leak but could`t find,will try to look better.
Thanks for advices

audi 200 87` MC1

Dikiz

could`t find vacuum leak,inspected visualy and sprayed everywhere starting fluid no reaction at starting fluid,so i think the with vacuum is ok...
Is it possible cloged fuel return lines?(but i removed line in trunk the fuel was flowing)
i have no ideas
i made a temporary fix with cold start valve button inside,Now starts easier,but not perfect...will try to find real problem...