328 EU, runs with poor fuel mixture between 1500 and 4000rpm

Check the rest position of your air flow sensor plate. I think your car is non lambda, could you give me the Bosch number on the side of your fuel distributor? It will be 0 438 100 034, or 0 438 100 139.

Larry Fletcher
CIS Flow Tech Llc.
251-929-3771
fletch62@bellsouth.net
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please tell me what exactely is done on the engine. What is just overhauled?
does this problem occure when engine is hot or cold or both?

( i'm from the europe - netherlands so no time difference.)

 

just asking,

do you KNOW mixture is poor or do you THINK it is poor?
say it with other words, do you think there patrol lacking (or excess air) or do know it for sure.

You can measure the amount of fuel comming from an injectors if you're not sure. use google to find the normal amount of fuel per injector with full no trottle and full trottle (lifting the airsensors-valve by hand)

As you also changed your ignitionsystem, the problem could be there to (someting with your advantagescurves)

What above the 4000 rpm, everything normal than again?

 

i think that if the pump was at fault you would not have proper running above 4000rpm.

co-adjust screw in normally only used for low rpm adjustment of CO-gas i though. it will change air/fuel ratio slightly over complete range so this explains what you see when adjusting it.

Thew WUR?. The WUR lowers the toppressure in above the fueldistributors needle when cold thus enriching the mixture. It should not work the other way around so i do not think the WUR is the problem ( do you experience difficult cold starts?)

above 4000 it runs fine but is the labda figure oke too? and for that matters: do you now for certain thr labde reading is correct?

false air somewhere from?

 

I had a simmilar problem in that the motor would run rough and seem to not get the right fuel mix and have a slight miss, (85 mondial QV) it turned out to be a small hole in one of the plug extenders, replaced it and problems went away, but as you have redone your ignition I asume you have checked all this over

 

oke we go from there after you know more about labda

But what kind of failure brings a faulty fuel distributor ?

a faulty fuel distributor CAN spoil your mixture. I came across one once which indeed had a prblem causing it to give to much fuel. I di thing these distributors are very rare to go into trouble.
I would not look at it only after sortad all other possibilities out

Actually i put a strobo light at the ignition cable, it seems that the
front bank with longer wires fires not so good as the rear bank.
Maybe its about the higher resistance so there is less current for
the strobo light to detect firing.

As said in an earlier post your ignition might be causing the problem. Did you change wiring. change anything?

you're welcome!

 

Your Fuel Distributor is a non Lambda version. You need to check your control pressure, if you need the specs give me your warm up regulator number and I can send them to you. What country are you in? Also if you need your fuel distributor and warm up regulator checked out I can bench test them. If you need more test info contact me by phone or email. I am a rebuilder of fuel distributors and warm up regulators. If you are German my girlfriend Luise is German and speaks it very well.

Larry Fletcher
251-929-3771
fax 251-929-0190
fletch62@bellsouth.net