Hpo
06-29-2022, 11:21 AM
#1
Hpo
My 3.3 Turbo has recently been difficult to start, harder when hot, let it cool down and it starts,
On cold start it just about starts and then misses or runs bad for about 10 seconds and then after that it is perfectly fine
I have been told it is the fuel accumulator, that it s faulty and to remove and pass air through the top, if the diaphragm is split then air will pass out the bottom but in some cases this may not happen but accumulator can still be faulty
Removed it from the car, that was a hard job as its tucked far in the left corner, tried the above test and no air comes out the bottom
When i released the fittings the two top lines had no fuel come out but the single lower port released a fair amount of fuel, not sure if this means anything
Is there any other way I can test if the accumulator is faulty.
On cold start it just about starts and then misses or runs bad for about 10 seconds and then after that it is perfectly fine
I have been told it is the fuel accumulator, that it s faulty and to remove and pass air through the top, if the diaphragm is split then air will pass out the bottom but in some cases this may not happen but accumulator can still be faulty
Removed it from the car, that was a hard job as its tucked far in the left corner, tried the above test and no air comes out the bottom
When i released the fittings the two top lines had no fuel come out but the single lower port released a fair amount of fuel, not sure if this means anything
Is there any other way I can test if the accumulator is faulty.
06-29-2022, 02:13 PM
#2
Rennlist Member
My 3.3 Turbo has recently been difficult to start, harder when hot, let it cool down and it starts,
On cold start it just about starts and then misses or runs bad for about 10 seconds and then after that it is perfectly fine
I have been told it is the fuel accumulator, that it s faulty and to remove and pass air through the top, if the diaphragm is split then air will pass out the bottom but in some cases this may not happen but accumulator can still be faulty
Removed it from the car, that was a hard job as its tucked far in the left corner, tried the above test and no air comes out the bottom
When i released the fittings the two top lines had no fuel come out but the single lower port released a fair amount of fuel, not sure if this means anything
Is there any other way I can test if the accumulator is faulty.
On cold start it just about starts and then misses or runs bad for about 10 seconds and then after that it is perfectly fine
I have been told it is the fuel accumulator, that it s faulty and to remove and pass air through the top, if the diaphragm is split then air will pass out the bottom but in some cases this may not happen but accumulator can still be faulty
Removed it from the car, that was a hard job as its tucked far in the left corner, tried the above test and no air comes out the bottom
When i released the fittings the two top lines had no fuel come out but the single lower port released a fair amount of fuel, not sure if this means anything
Is there any other way I can test if the accumulator is faulty.
Helio
06-29-2022, 02:36 PM
#3
I have removed it and it was very difficult to remove, its nearly 30 years old,so may as well replace it with a bosch unit, I assume the porsche part is also a bosch unit.
06-29-2022, 02:51 PM
#5
The pressure accumulator is checked mounted in by connecting a pressure gauge between the fuel distributor and WUR.
The system pressure must not drop below 1.6 bar 10 minutes and not below 1.4 bar 20 min. after the fuel pumps have been switched off.
In the same configuration your were able to check the system pressure and the control pressure hot and cold, which should be done on your car.
I think you can continue in this way for a long time without finding the error, or you will change unnessessary expensive part .
You don't know the CIS and its correlations and you don't know how to check the components. This is not an accusation but a statement combined with the recommendation to look for someone in your area who has the skills. Its not a rocket science but you should know the basics.
Cheers, Fritz
The system pressure must not drop below 1.6 bar 10 minutes and not below 1.4 bar 20 min. after the fuel pumps have been switched off.
In the same configuration your were able to check the system pressure and the control pressure hot and cold, which should be done on your car.
I think you can continue in this way for a long time without finding the error, or you will change unnessessary expensive part .
You don't know the CIS and its correlations and you don't know how to check the components. This is not an accusation but a statement combined with the recommendation to look for someone in your area who has the skills. Its not a rocket science but you should know the basics.
Cheers, Fritz
06-29-2022, 04:16 PM
#6
Thanks, I could check if i had a manual , I have built engines, head rebuilds etc so have some mechanical experience, would really like to learn the cis system
Is there a manual for the 964 turbo i can download
Is there a manual for the 964 turbo i can download