'87 Renix 4.0L Auto: weak vs strong fuel-pump sound when cranking

[MikeESoc2]

Here's some further info that I just dug-up in the change log detail for the 5 family vehicles I maintain:
'87 XJ: 05/18/2009: 307,561 miles (which was ~ 21K miles ago):
replaced OE fuel pump with Carter Pkg# 74155 (a bosch pump with a 1-yr warranty).

Given the post I sent yesterday with the posts from ~ 11/2010 and ~ 12/2008 regarding ~ 2-year-old bosch fuel pump failures (altho those reported failures were the bosch #69302 turbine pump failures), perhaps it is a case that there were a recent handful of years that the bosch fuel-pump quality-control or bosch manufacturing took a dive.

And the further thought is that if those failed pumps were just so happen purchased via RockAuto, then RockAuto knows nothing about what appears to be a # of bosch fuel pump failures that occured ~ 2 yrs after install
since the pumps are warrantied for only 1 year (return-replace not available)
- and for that matter,
Bosch knows nothing about them for the same reason.

I have no knock against bosch
- I like their inexpensive mag-plus spark plug wires;
- have used their +4 plugs in the past (but I think they wear-down too quick);
- usually use their water pumps (but for the recent '87 water-pump chg I did this Spring 2011 I used a new Cardone Select pump instead);
- overall I like their frontal lighting (have couple of Bosch Euro-spec H4 rectangular headlamps (from Canada) replacing the front H6054 in this '87XJ for the past ~ 8 years, and, bosch Compact 100 fog lights in the OE locations on the '94 Bonneville that I hand-made custom-installs for).

But without doubt,
the next fuel pump for this '87 XJ will not be a bosch pump
- am curently un-decided whether:
Carter #P74057 with the Walbro pump, or,
Omix-Ada #1770909 pump, or,
Denso #9503024 (which is also a Walbro pump pkg but with a turbine pump).

 

[Ecomike]

One thing I always try to keep in mind, is that problems sometimes come in pairs, multiple problems, that make diagnosis harder. Parts on Jeeps like to fail at the same time. Like grounds, wiring, relays, hoses, pumps...

I would be real curious what the voltage at the pump was in all those cases.

In the last 4 years I fixed our 89 and 87 fuel pump (dead) problems just cleaning wire connections.

 

[MikeESoc2]

Here is the latest research info:

I called Carter Tech-Support (which is Federal-Mogul tech-support) this morning:
http://www.federalmogul.com/en/ContactUs/
1.800.325.8886.
to ask them about inter-change-ability for
Carter #P74057 (Walbro OE fuel pump)
Carter #P74155 (Bosch OE fuel pump)
and
to ask them as to whether their P74155 contains a Bosch-brand pump or a Carter-brand pump
(since P74155 was used ~ 2 years ago to replace the OE pump on this '87 XJ)..

Per F-M tech-support:
a) the 2 Carter #s are NOT inter-change-able;
b) P74155 is a Carter-brand pump (it is NOT a Bosch-brand pump).

Therefore:
the failed pump in this '87XJ is a failed Carter pump ... NOT a failed Bosch pump
(which negates my last post from yesterday 07/20/2011 evening).

Additonally (and this may be important):
on the F-M web site there is a choice of only 2 languages:
English and Chinese
(therefore: I am reasonably guessing that the Carter pumps are made in China ...
... hmmm ... with an ~ 2 year failure ... at least in this vehicle).

I then called Omix-Ada tech-support:
1-770-614-6101

Spoke to an Omix-Ada tech-rep named Ryan,
and I asked the following 2 questions:
is the Omix-Ada pump (part #1770909, which is super-ceeded by part #4637193)
use-able for XJ's with either the Walbro OE pump or the Bosch OE pump,
and,
where is the Omix-Ada fuel-pump made.

He needed to research, and, he called me back with this info:

The Omix-Ada fuel-pump #1770909 is only for bosch pump XJs.

From everything that he and the Omix-Ada tech staff could find
(via something called e-fisches that have been converted to PDF-format catalogues):
the Omix-Ada tech-staff conclusion is that nearly all the XJ 4.0 fuel-pumps are "bosch type"
since it looks to them that the Walbro in-tank pumps were used with the XJ 2.8L GM engine vehicles
- and possibly -
some of the very-early '87 XJ 4.0L could have a Walbro OE pump.

Since the 2-year old failed pump in this '87XJ was from a Carter #P74155 (Bosch),
it appears that this '87 XJ uses the bosch-type pump.

Ryan also said that the XJ fuel-tank size is NOT related
to whether a Walbro or Bosch was originally installed
- reminder:
this '87 XJ has a 13..5 gallon tank.

Regarding where the Omix-Ada pump is made:
Ryan says:
in St. Louis.

So no more drifting around on the decision:
I am buying the Omix-Ada fuel-pump #1770909.