This truck has a 4.9L engine with a 3 speed automatic transmission. It has
approx. 109,000 kms and it runs very well for its age. I had it on the
highway today because I needed it for work, probably only the 3rd or 4th
time I've driven it on the highway since I've owned it. Besides revving
quite high (usually around 3000 - 3500 @ 110 km/h), I noticed it was
starting to hitch while driving up long inclines or hills in general. On
the way to work, it did not do this, only on the way home. If you try to
accelerate past 115 km/h, it would suddenly start sputtering and then 3-4
seconds later it would be fine. It almost acts as if it is running out of
fuel, which it is not. Usually it would do this in 5-6 cycles and then it
would work normally again. In the 45 minute drive home, it did this
probably 4 times altogether.
What I want to know is whether this truck has the spark box/ignition module
that seems to be a common cause of problems on older vehicles. I've read a
few posts recently that were similar in nature to my problem and the
solution was to clean the electrical connections and reapply new heatsink
grease. There is an electrical module mounted to the drivers side inner
fender that has the word "Standard" on the face of it. It kind of looks
like a heatsink, about 10" x 10" square. I haven't tried to unbolt it and
look for other markings, but I can also tell you that there is a flat wiring
connection on the bottom front of it that splits into two round wiring
harness connectors. These are both connected to harnesses that lead into
the distributor (I think, one goes there for sure).
If it turns out to be the spark box at fault, are these replaceable with
aftermarket parts made by Accel or others? Or would I have to go to the
dealer for a replacement? It seems to me that the first car I owned, a 1986
Tempo, had the same type of problem. It would suddenly bog out and
sometimes stall. I remember replacing some type of ignition/spark box,
seems to me it may have been the same part, but that was over 12 years ago.
Thanks for any info.