|
| |
| Stock/factory
fuel injection system
installed in Cabriolets |
|
Year |
Fuel Injection System |
Notes |
|
1980 -- 1989 |
CIS |
*If the 5th digit in the VIN is "B" it's
Digifant II, if it's "C" it's Digifant I. All 1990 Cabriolets
initially sold in California are Digifant II with unique features; all
1991-1993 Cabriolets initially sold in California are Digifant I. All
other 1990-1993 Cabriolets sold in the USA are Digifant II.
**Cabriolets did
not
ever come from the factory with CIS-E nor diesel engines!** |
|
1990 -- 1993 |
Digifant I or Digifant II* |
|
One system is not necessarily "better"
than the other. CIS is said to be easier to work on and
troubleshoot and contains less expensive parts than the Digifant
because Digifant is computerized and relies on electronic sensors
and other devices to work properly. CIS, however, because it's a
mechanical fuel injection system, is said to be more finicky than
Digifant and requires fine-tuning to run perfectly. Digifant
engines produce a bit more horsepower than CIS and slight horsepower
gains can be achieved with Digifant by simply "chipping it". Proper
maintenance is the key to a nearly problem-free car, no matter what
fuel injection system it has.
|
|
| Differences between CIS, CIS-E and Digifant |
|
CIS |
Mechanical fuel
injection on 8v engines utilizing the
Bosch K-Jetronic system |
|
CIS-E |
Mechanical fuel injection with electronic
controls on 16v engines |
|
Digifant II |
Electronic fuel injection on 8v engines |
|
Digifant I |
Electronic fuel injection on 8v engines
with OBD I diagnostics |
|
|
Fixing/setting/adjusting
the idle |
|
|
| Testing the system's fuel
pressure |
|
Click here
for a CIS how-to.
Click here for a CIS fuel pressure tester.
Click here
for how to make a fuel pump on-off switch for when testing the fuel system. |
|
CIS
Troubleshooting Guide |
|
Above image is care of
the Bosch Service Guide. |
| Fuel filters |
|
CIS
To VIN: E_11290 |
CIS
From VIN: E_11291 |
Digifant
1990-1993 |
|
Volkswagen part #431 133 511 D
Bosch (part #0 450 905 401) -- OEM
Beck Arnley (part #043-0660)
Deutsch (part #FF600) |
Volkswagen part #893 133 511
Bosch (part #0 450 905 133) -- OEM
Beck Arnley (part #043-0798)
Fram (part #G7346)
Purolater (part #F50155)
AC/Delco (part #GF527) |
Volkswagen part #1H0 201 511 A
Bosch (part #0 450 905 030) -- OEM
Mann (part# N/A)
Fram (part #G3829)
Purolater (part #F60146)
AC/Delco (part #GF358) |
|
CIS fuel filter is in
the engine compartment, mounted to the driver's side fender between
the battery and coolant tank. |
Digifant fuel filter is
located under the car, near the main fuel pump. |
|
Volkswagen part #533
201 511 A -- rectangular filter near the fuel pump for those with
"fuel expansion tanks" |
|
| Fuel pumps
|
| Fuel injected Cabriolets from
1984* to 1993 have 2 electric fuel pumps. The main fuel pump is located
beneath the car, passenger side, in front of the gas tank. The second pump,
called a transfer pump, is located inside the gas tank; access to this pump
is on the passenger side under the rear seat. Both of these pumps are wired
to the fuse/relay panel. If a pump fails to operate, check the fuse and
relay first. A fuel pump check valve
is connected to the main fuel pump. This device helps in preventing vapor
lock and helps maintain fuel system pressure after the engine stops. On CIS
engines, this part can be replaced independent of the pump; on Digifant
engines, the check valve is part of the fuel pump and cannot be replaced
separately.
NOTE: A CIS external fuel pump can be
used on a Digifant system when need be, but a Digifant external fuel pump
cannot be used on a CIS system. The Digifant fuel pump does not produce
enough fuel pressure required by the CIS system to run efficiently.
* Only about half of the 1984 models have
in-tank fuel pumps. To find out if your 1984 convertible has an in-tank
pump, look at the VIN; if the last 5 digits end with 11291 or higher, your
car should have an in-tank pump (those cars with a
full-size spare tire in the trunk do not have in-tank fuel pumps).
|
|
Running the fuel tank
dry |
| Nine times out of ten, when
the tank is allowed to run dry, the in-tank fuel pump is
damaged; therefore, replacing the in-tank fuel pump is the only solution. Sometimes, this problem also
affects the external fuel pump and the fuel filter. Change the fuel filter
when replacing the in-tank pump. There is also a filter screen attached to
the in-tank pump; make sure this clean or new when checking or replacing the
in-tank pump. And: Let this be a lesson and warning to never, ever let the
gas tank run dry! |
|
Gasoline |
|
Countries using the RON octane rating
 |
Countries using the (R+M)/2 octane rating
 |
|
JH, 2H, EW, JB, FA, FN, FV, JB, EM, GG,
GH, HK, HN, EW, EX engines:
Unleaded, 91 minimum
EG engines:
Unleaded, 95 minimum
DX, KT, JJ engines:
Unleaded, 98 minimum |
EJ, EN, JH, 2H engines:
Unleaded, 87 minimum
|
|
Click here for more gasoline information. |
|
|
The gas
tank is leaking! |
| Take your Cabriolet to your
local Volkswagen dealer for a gas tank inspection; certain years of
Cabriolets had a recall on the tanks which is still honored by Volkswagen
(by law).
Click here for further information. If your Cabriolet is not
covered by the recall, the gas tank will need to be repaired or replaced.
No; a hard-top Rabbit/Golf gas tank will not
fit. The gas tanks for these cars are Cabriolet-specific.
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