Jeep Cherokee 1999 Electronic Service Manual page 1199

14 - 8 FUEL SYSTEM
DI AGN OSI S AN D T EST I N G (Cont inue d)
Fig. 8 Connecting Adapter Tool—Typical
(4) Con n ect t h e 0-414 kP a (0-60 psi) fu el pr essu r e
t est ga u ge (fr om Ga u ge Set 5069) t o t h e t est por t on
t h e a ppr opr ia t e Ada pt or Tool. Th e fittin g s o n bo th
to o ls m u s t be in g o o d c o n d itio n a n d fre e fro m
a n y s m a ll le a k s be fo re p e rfo rm in g th e p ro c e e d -
in g te s t.
(5) St a r t en gin e a n d br in g t o n or m a l oper a t in g
t em per a t u r e.
(6) Obser ve t est ga u ge. Nor m a l oper a t in g pr essu r e
sh ou ld be 339 kP a
(7) Sh u t en gin e off.
(8) P r essu r e sh ou ld n ot fa ll below 30 p s i fo r fiv e
m in u te s .
(9) If pr essu r e fa lls below 30 psi, it m u st be det er-
m in ed if a fu el in ject or, t h e ch eck va lve wit h in t h e
fu el pu m p m odu le, or a fu el t u be/lin e is lea kin g.
(10) Aga in , st a r t en gin e a n d br in g t o n or m a l oper-
a t in g t em per a t u r e.
(11) Sh u t en gin e off.
(12) Te s tin g fo r fu e l in je c to r o r fu e l ra il le a k -
a g e : Cla m p off t h e r u bber h ose por t ion of Ada pt or
Tool bet ween t h e fu el r a il a n d t h e t est por t "T" on
Ada pt er Tool. If pr essu r e n ow h olds a t or a bove 30
psi, a fu el in ject or or t h e fu el r a il is lea kin g.
(13) Te s tin g fo r fu e l p u m p c h e c k v a lv e , filte r/
re g u la to r c h e c k v a lv e o r fu e l tu be /lin e le a k a g e :
Cla m p off t h e r u bber h ose por t ion of Ada pt or Tool
bet ween t h e veh icle fu el lin e a n d t est por t "T" on
Ada pt er Tool. If pr essu r e n ow h olds a t or a bove 30
psi, a lea k m a y be fou n d a t a fu el t u be/lin e. If n o
lea ks a r e fou n d a t fu el t u bes or lin es, on e of t h e
ch eck va lves in eit h er t h e elect r ic fu el pu m p or filt er /
r egu la t or m a y be lea kin g.
34 kP a (49.2 psi 5 psi).
Not e: A qu ick loss of pr essu r e u su a lly in dica t es a
defect ive ch eck va lve in t h e filt er /r egu la t or. A slow
loss of pr essu r e u su a lly in dica t es a defect ive ch eck
va lve in t h e elect r ic fu el pu m p.
Th e elect r ic fu el pu m p is n ot ser viced sepa r a t ely.
Repla ce t h e fu el pu m p m odu le a ssem bly. Th e filt er /
r egu la t or m a y be r epla ced sepa r a t ely on cer t a in
a pplica t ion s. Refer t o F u el F ilt er /F u el P r essu r e Reg-
u la t or Rem ova l/In st a lla t ion for a ddit ion a l in for m a -
t ion .
FUEL PUMP AMPERAGE TEST
Th is a m per a ge (cu r r en t dr a w) t est is t o be don e in
con ju n ct ion wit h t h e F u el P u m p P r essu r e Test , F u el
P u m p Ca pa cit y Test a n d F u el P r essu r e Lea k Down
Test . Befor e per for m in g t h e a m per a ge t est , be su r e
t h e t em per a t u r e of t h e fu el t a n k is a bove 50° F (10°
C).
Th e DRB Sca n Tool a lon g wit h t h e DRB Low Cu r-
r en t Sh u n t (LCS) a da pt er (F ig. 9) a n d it s t est lea ds
will be u sed t o ch eck fu el pu m p a m per a ge specifica -
t ion s.
Fig. 9 Low Current Shunt Adapter
(1) Be su r e fu el t a n k con t a in s fu el befor e st a r t in g
t est . If t a n k is em pt y or n ea r em pt y, a m per a ge r ea d-
in gs will be in cor r ect .
(2) Obt a in LCS a da pt er.
(3) P lu g ca ble fr om LCS a da pt er in t o DRB sca n
t ool a t SE T 1 r ecept a cle.
(4) P lu g DRB in t o veh icle 16–wa y con n ect or (da t a
lin k con n ect or ).
(5) Con n ect (-) a n d (+) t est ca ble lea ds in t o LCS
a da pt er r ecept a cles. Use 10 a m p (10A +) r ecept a cle
a n d com m on (-) r ecept a cles.
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