This is a follow up on to my recent post (see below) about some
electrical problems I had with my 1984 XJ6 VdP. Thanks for all the
helpful advice.
As some of you might remember I disassembled most everything on the
interior and exterior of this car for a repaint. In addition I replaced
the instrument panel and replaced it with a NOS OEM burlwood dash, I
removed and replaced all the seats and center console and treated and
dyed all the leather and vinyl. For all practical purposes the car now
looks brand new. But of course lots of things had to be taken apart and
put back together properly.
I was definitely in a rush to get the car ready for the concours season,
so it wasn’t surprising that a few gremlins popped up.
It looks like I fixed both my engine power loss and instrument panel
power problems from the original post.
I believe the engine power loss was either a bad power resistor
or bad connection to the power resistor. I believe I was only running
on three cylinders as only three fuel injectors were firing. I removed
all the wires from my old cracked plastic power resistor connector and
replaced it with a good one from my spare parts car. In the process I
cleaned up all the dirty and tarnished contacts, oiled them with
dielectric grease and replaced the power resistor with a spare one.
I believe that the instrument panel gage power problems were due
to my removal of an aftermarket “Headlights On Reminder Buzzer” that I
removed right prior to the concours to avoid questions if the buzzer
should go off during the Operation Verification test. I think I must
have loosened the fuse. I reinstalled the “Headlights On Reminder
Buzzer” and haven’t had a problem with the gages since.
Of course I also removed, cleaned, oiled and replaced the
battery cables, the main power terminal post and ground, the gage
grounds at the rear of the instrument panel and the grounds at the rear
of the coolant rail. I took the battery in to a local auto parts shop
and it checked out good. Any or all of them could have been at least
partially to blame.
I didn't suspect the ignition switch as I replaced that a few
years ago and upon visual inspection it didn’t appear to have any issue.
I have put on about 500 miles since fixing things and everything was
been working correctly.
Regards,
Paul M. Novak
1990 XJ-S Classic Collection convertible
1984 XJ6 Vanden Plas
1969 E-Type Fixed Head Coupe
1957 MK VIII Saloon
1985 XJ6 Vanden Plas (parts)
Ramona, CA
@Paul_M_Novak1-----Original Message-----
From: owner-xj@jag-lovers.org [mailto:owner-xj@jag-lovers.org] On Behalf
Of Paul M. Novak
Sent: Monday, October 08, 2007 1:14 PM
To: xj@jag-lovers.org
Subject: [xj] Engine and electrical strangeness, 1984 XJ6 VdP {Scanned}
I had two problems this weekend with my 1984 XJ6 VdP, the first was an
intermittent loss of engine power and the second was an intermittent
loss of electrical power to the instrument panel gages. I was away from
home at the time, didn’t have the tools or a place to work on the car
and needed to continue to make some scheduled events. Since the car
kept running, I kept driving it until we both returned home safely
yesterday afternoon.
I first noticed that the engine wasn’t delivering normal power while
pulling out onto a main road after having driven about 60 miles. The
car was very sluggish and accelerated very slowly. It was as if the
car was running on only 3 cylinders. At the first traffic light I
noticed that the idle was a little lower than normal and a bit lumpy so
I pulled over and opened up the hood to inspect things while the engine
was running. The engine continued to run and all gages were reading OK
and I didn’t see anything wrong so I continued to drive it. The car
was very slow to accelerate, and I had trouble maintaining speed going
up hills. It was possible to attain and maintain highway speeds of 60
MPH if the road was flat. I experienced something like this before was
when the power resister had failed. In that case I verified that all
spark plugs were firing but only 3 fuel injectors were firing using my
mechanics stethoscope. Since I didn’t have the right tools or a spare
power resistor with me this time, I continued to drive the car hoping to
make it home. This didn’t appear to be a clogged catalytic converter
since it was evident at all engine speeds and not just a loss of power
when high power was demanded. I considered that it could possibly have
been a clogged fuel filter, but thought this unlikely as I replaced the
fuel filter in May after getting the car back from the paint shop.
While driving home with the continued engine power problem I then
noticed that my speedometer and tachometer went to zero and that all of
my instrument gages had lost power. I put on my emergency flasher
(which did work) to pull over, but by the time I had started to pull
over, the speedometer and tachometer came up and everything was reading
properly again. I drove for another few minutes until this happened
once more, so I pulled over and again left the engine running to see if
I could detect a problem. Nothing was evident, other that the slightly
lumpy idle. All connections appeared tight, no hoses were disconnected
and everything looked as it should even the gages again.
As I started the final 30 mile leg home, the engine power mysteriously
returned to normal and the gages all read normal all the way home.
I started up the car today and everything appears normal.
As precautionary actions I plan to:
- Remove and replace the fuel filter. I’ll cut the old one open to
inspect for anything that might have caused restricted fuel flow but I
don’t expect to find any problems or rust/debris. Both tanks have been
professionally cleaned and sealed.
- Remove and replace the power resister with a spare one checking the
connector for any problems and wires for breaks or corrosion
- Remove the battery and bring it in to a local shop for testing.
It’s about 3 years old but remains strong and the engine always jumps
immediately to life within a second when starting.
- Remove, clean, oil and replace the ground wires on the back of the
coolant rail
- Remove, clean and replace the lower grounding strap between the
engine and chassis.
Is it possible that these problems are related?
Should I suspect the alternator?
Any other suggestions?
Regards,
Paul M. Novak
1990 XJ-S Classic Collection convertible
1984 XJ6 Vanden Plas
1969 E-Type Fixed Head Coupe
1957 MK VIII Saloon
1985 XJ6 Vanden Plas (parts)
Ramona, CA
@Paul_M_Novak1
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