Engine Performance problem
1986 Questions for all other cars V8 Two Wheel Drive Automatic 52000 miles
I actually have two questions, about my 1986 Winnebago RV that has a chevy 454 engine in it.
The first problem is misfires. The vehicle sat with approximately 14 months with half a tank of gas in it. This spring I had it tuned up, timing, plugs, cables, etc. I didn't drain the old gas but I did top it off with premium and put in some additives. It ran fine for the first 100 or so miles. Then it started misfiring when I was going up hills. It started very subtlely, but soon progressed to where I was concerned about making it home. I was down to about 1/2 a tank of gas, so I topped it off with premium again, but it didn't help. It only misses under load. I did some research that said check the spark plug cables, but they are new. I was wondering if it perhaps was the fuel pump, or fuel filter. Any suggestions would be appreciated.
My second question. My temperature gauge doesn't work. I wasn't concerned about it until the other problem developed, and I've read that these engines have a tendency to run hot. I'm guessing it's not the gauge itself since the other functions on it are ok, so what component are there, and what do I need to look at? Am I better pursuing an aftermarket product, and if so, what would you recommend.
On an unrelated note, I'm happy to donate, this is a great site, but I couldn't find a suggested amount. If $10 isn't enough, please let me know. Thanks Jon
Some additional info please: Is it port FI, or TBI, or carb?
Whenever you store a vehicle for that long you should use a fuel stabilizer in the fuel to prevent varnish build up in the fuel system.
Premimum fuel will not help you (in fact may hurt). If the engine was designed for 87 octane, use it.
Changing the fuel filter will not hurt, but the fuel left in the vehicle may be the problem (varnish in the fuel system).
The coolant temp sender may be bad or the gauge itself.
If you go aftermarket, I would suggest an Autometer mechanical gauge.