View Full Version : Carb Bucking when trying to give more gas going uphill

08-03-2011, 12:46 PM
I'm roughly halfway through my 600-mile drive back from PA to home in KY, and up until the last 20 minutes before I stopped for lunch, the car behaved very well. However, shortly after it started raining, coming to the top of one of the hills, I suddenly became unable to get the engine to go above about 3K RPMs before it would start bucking and fighting me. It did this in any gear I tried.

Since my D is carbed, it seems unlikely it's a fuel issue- it simply wouldn't run were that the problem. My best guess is that the timing was getting off- could the spark advance be having issues?

I'm also fairly convinced my temperature gauge is stuck- again- but the engine shut down without any complaints and didn't diesel like it does when it gets overly hot, so I don't think it's an overheating issue...

I'm taking a leisurely lunch to let it cool down from the mountain driving and to see whether the temp gauge decides to behave... any thoughts on what could have caused the hesitation would be appreciated (and how to check & correct it...)

08-03-2011, 12:55 PM
Fuel starvation doesn't "buck and fight." It's more of a sputtering and dieing sensation -- not violent at all (if you've ever run a tank low/out of gas you know what I mean).

When in doubt, pop the top off the carb. If there's gasoline in the bowl, you aren't starved for fuel. I had to catch one of my church's school buses red handed on the side of the road (fuel bowl dry) to diagnose a compromised tank pickup.

Bill Robertson

08-03-2011, 01:02 PM
As I noted, I don't think it has anything to do with fuel- the note was just to (unsuccessfully, it would appear) attempt to steer discussion away from that as a potential problem.

Since we've largely eliminated what it isn't, thoughts on what it could actually be and how to fix it?

08-03-2011, 01:11 PM
You haven't eliminated it. Pop the top off the carb and look inside.

I am going to start modifying my top gaskets with a hole underneath at least one of the chimneys so you can put a dip stick into the bowl.

Did it feel like a misfire? Misfires can be pretty bucking/fighting.

Bill Robertson

08-03-2011, 01:22 PM
Mountain driving will really find any problem with any car.

Maybe it's just an ignition component overheating. Try driving with your coil cover off (if you have one).

08-03-2011, 01:35 PM
You mentioned rain, is there water in the plug wells?

08-03-2011, 09:47 PM
Did Bob make it home?

Bill Robertson

08-03-2011, 11:14 PM
I did- sorry, my girlfriend took solidly higher priority upon getting home. ;)

The second half of the drive after lunch was far less eventful than the first half (which wasn't that bad compared to the drive out, I can tell you that!). The only 'issue' I had was that the cruise control doesn't apparently let me set it over about 70, but that was a very minor issue and one that I think I know how to fix.

The issue with the ending bucking/misfiring/etc. didn't show back up at all, despite having a modest bit of mountain driving after lunch as well. Admittedly, I didn't turn on the air (which actually I believe was off when the issue happened) until I was about 200 miles from home, and didn't use the cruise until within towing distance. There was however no very heavy rain to deal with like I had been earlier... so I really don't have any clue what the problem was. This is nice in that I'm happy to have made it home without major incident- but at the same time, it remains an unsolved mystery that could rear its head again unexpectedly.

I did find that the temp gauge was stuck, but thankfully found that a paper clip stuck through the trip reset hole in the plexiglass was capable of knocking it loose so I didn't have to pull the binnacle to get it free like I did last time. *sigh* I suppose I'm going to have to replace that part of the cluster... I can't be constantly poking it with a paper clip to make sure the temp it's showing is accurate and that it's not just stuck...