Hey all, Been trying to figure out why my 93 Carry is losing power. Been posting and reading and have gotten to a point where I'm looking for more direction. Essentially the truck stumbles and bogs when going through soft ground or up hill. Example up hill: when going up a long (not that steep) hill or a smaller more off road hill it loses power super quickly. If I don't pop the clutch in and give it gas, it'll stall. Anyway, with some help I tested the fuel pressure and vacuum pressure as well. The fuel read around 3psi and have been told it should be around 2. Vacuum was a little all over the map - first few mins it was around the 5 mark. Rev’d it a bit and it went up to about 15-16 then back down steady to 8. It started there for a few mins. but after idling for a bit it was low at around 13. vid: https://youtube.com/shorts/ra_syvHvwGM?feature=share Checked the plugs and they all seem black and sooty (pic attached). I'm thinking I should get the fuel pressure down and hope that solves it. Looking at some other threads I'm also seeing that it could be something with my exhaust / CAT? Any thoughts here? I'm hopefully getting close to diagnosing the problem but would love your thoughts on what I should try next. Appreciate all your help so far! thanks, kyle
Hey Ronin, Thanks for the reply. Not sure. Haven't poked at that yet. What's its role? Any tips on locating it on the carb and how to test to see if it's working or not? Thanks! kyle
It's a flap on the intake side of the carb, its role is to enrich the air/fuel mix when the engine is cold by cutting off some airflow. On the F6A it's notoriously finicky, due to a slightly over complicated system of operation which includes water pipes and a thermostatically operated wax element actuating mechanism. This can fail for any number of reasons: Coolant not reaching it/circulating properly (or just plain disconnected due to perished hoses) a failure of the wax thermostat itself or perhaps just becoming 'unadjusted' over time. Pull the air intake off the carb, you'll see the flap. Start the engine and let it warm up, and you should see the flap start to open up. Note the air temperature when you do this. Warm and the flap should be somewhat open when started and open fully quickly (within a few minutes). There are penny-wise ways of dealing with the issue. On my old truck I adjusted the choke to just barely close (ie mostly open); the engine would still start just fine in the cold but wanted a tad warming up before it was really ready to go... no problem. You could also unhook the automatic actuating mechanism and run a cable with a knob to the dash; there may be already a provision for mounting one on there... there was on my old DB51T. Anyhow that's where I'd start. Highly likely. While you're under there put an eye on the gajillion vacuum hoses and see if they all look intact.
Thanks Ronin. I actually did notice this yesterday and was trying to figure out what controlled that. It was wide open but the engine was warm (looked at it after I drove it around a bit). I also noticed that my idle rpm is super high like 2000 mark. Tried adjusting the idle mixture screw but didn't do a whole lot (might've been doin it wrong too). Checked most of the vacuums this weekend as well and all seems good. Did a compression test and the all held around 170... the 1st one (far right) was around 160. Also checked the vacuum again and it hovered around 13. Seems low. Also noticed the smell of gas in my oil on the dipstick. All signs of running rich i guess. Gotta figure this out! Thanks again for your help. Onward! kyle
