As the title states, this makes for some very hard hot starts. I'll give some background, now.....
The 81 1.7 Rabbit was put on the road about 1 month ago and it got a new Bosch pump and check valve. A new accumulator was also installed, because the old one had staining around the weep screw. One week ago, the problem started.
The problem is worse during the day, when it's hot and vaporlocks. It isn't as bad at night when it's cooler. Once you get the car started, (seems to respond favorably to starting fluid) it runs perfectly. Turn the car off and within 5 seconds the pressure drops to 10lbs; 20 seconds later, it's at 0. Pressing the bleed button on the gauge (and getting no fuel spray) verifies it's not a faulty gauge.
- Dwell is perfect between 40/50
- frequency valve impedance reads within spec @ 2.7 ohms
- warm control pressure is @ 52 lbs.
- warm system pressure is @ 78 lbs.
- injectors and CSV are not leaking
- hot start relay is working, and by the short spurts of life, I can tell the CSV is firing
- Fuel dizzy plunger moves freely
- No leaks that I can see or smell from the rear of the car, to the front
- the tank is definitely holding pressure.... releasing the cap gives the telltale hiss. I even lowered the tank to verify all the vent lines were attached and tight.
Now, the Bentley tells you if the mixture goes way lean when checking system pressure, the pump check valve is probably bad. My dwell bounced between 55/65 lbs., so I replaced the new check valve with another check valve. No change and still the same dwell reading with the swapped check valve. I pulled the new accumulator and replaced it with another nonstained accumulator. Same deal.
The fuel dizzy has a pressure relief valve, but I thought it's only for maintaining system pressure, not residual pressure. Could that be the culprit, or any other ideas.... I'm stumped.
-Todd
The 81 1.7 Rabbit was put on the road about 1 month ago and it got a new Bosch pump and check valve. A new accumulator was also installed, because the old one had staining around the weep screw. One week ago, the problem started.
The problem is worse during the day, when it's hot and vaporlocks. It isn't as bad at night when it's cooler. Once you get the car started, (seems to respond favorably to starting fluid) it runs perfectly. Turn the car off and within 5 seconds the pressure drops to 10lbs; 20 seconds later, it's at 0. Pressing the bleed button on the gauge (and getting no fuel spray) verifies it's not a faulty gauge.
- Dwell is perfect between 40/50
- frequency valve impedance reads within spec @ 2.7 ohms
- warm control pressure is @ 52 lbs.
- warm system pressure is @ 78 lbs.
- injectors and CSV are not leaking
- hot start relay is working, and by the short spurts of life, I can tell the CSV is firing
- Fuel dizzy plunger moves freely
- No leaks that I can see or smell from the rear of the car, to the front
- the tank is definitely holding pressure.... releasing the cap gives the telltale hiss. I even lowered the tank to verify all the vent lines were attached and tight.
Now, the Bentley tells you if the mixture goes way lean when checking system pressure, the pump check valve is probably bad. My dwell bounced between 55/65 lbs., so I replaced the new check valve with another check valve. No change and still the same dwell reading with the swapped check valve. I pulled the new accumulator and replaced it with another nonstained accumulator. Same deal.
The fuel dizzy has a pressure relief valve, but I thought it's only for maintaining system pressure, not residual pressure. Could that be the culprit, or any other ideas.... I'm stumped.
-Todd