Tachometer Issue on 1998 Bravada

I’ve been commuting roughly 100 miles round trip daily for work for the past month or so and other than the need for an oil change (I’m at about 6,000 since the last one, current mileage is 171900), my 98 Bravada has been fine. However, this evening when I was about half-way home, I noticed the car was getting a little resistance on accelerating. I had wondered if it was the wind and rain I was driving through, but the tachometer was jumping regularly, it was in the lower ranges (between 1-2, maybe a jump to 3). I was still able to maintain speed (up to 60mph, and a struggle to get to 65 - somewhat unusual) - however there was noticeable resistance to acceleration. Once I got home I noticed that the temp gauge was showing less than 150 and the oil was fluctuating between 1/4 and 1/2.

I’m crossing my fingers that there is a simple (and very inexpensive) solution out there as my job is ending in 4 weeks and I’m on a strictly tight budget. Any ideas or diagnoses out there?

Erratic engine operation can manifest itself as erratic voltage and your symptoms, and erratic operation on a rainstorm generally points to ignition system component problems.

However, a bad alternator or bad batter connection can menifect the same symptoms.

First I’d get the battery and charging system checked. Then I’d replace the routine-maintenance ignition parts of they haven’t been done for awhile.

If you still have the problem, it’ll take someone hands-on, preferable with the diagnostic equipment to see what the spark pulses look like…and with a spray bottle full of water.