85 22R missing uphill

[Combat Chuck]

The 85 22R motor in my 83 pickup recently (within the last 72 hours) developed this funny habit of missing while pulling hills in gears 3, 4, or 5.

I first thought it was fuel delivery, so I changed up the filter, checked the pump, the usual, but it's not a violent "buck" just a faint stumbling. I've also just had my valves adjusted yesterday, and I'm getting ready to wave a timing light at my dizzy menacingly, as well as check my plugs and wires. Are there any other places I should look? What else can cause a miss at speed?

Ruled out:
- fuel delivery

Potentia:
- dizzy timing
- loose plug wire
- carb float
- Ignition coil

anything else I'm missing?

 

[Combat Chuck]

Just finished peeking at the plugs - they look like crap, lots of ashing, gaps are short, too.

 

[TurboDiesel69]

Make sure that your hose clamps are tight on your fuel lines... the Toyota ones are horrible.


I had this problem and new hose clamps fixed it. (had to back up hills it was so bad)

 

[Combat Chuck]

Make sure that your hose clamps are tight on your fuel lines... the Toyota ones are horrible.


I had this problem and new hose clamps fixed it. (had to back up hills it was so bad)

I will look at my hoses, too. they're 50/50 aftermarket/stock right now.

 

[Combat Chuck]

Make sure that your hose clamps are tight on your fuel lines... the Toyota ones are horrible.


I had this problem and new hose clamps fixed it. (had to back up hills it was so bad)

I will look at my hoses, too. they're 50/50 aftermarket/stock right now.

 

[80t0ylc]

What carb have you got on it? I put a Weber on a '85 D50 some years back that developed some similar symptoms to what you're seeing. Turned out to be that the OEM Mitsubishi mechanical fuel pump could not keep the bowl in the carb supplied with enough fuel during high power requirements. An electric fuel pump fixed it after some frustrating problem determination. Fuel lines sound like a possibility, also, if they are questionable.

 

[Combat Chuck]

What carb have you got on it? I put a Weber on a '85 D50 some years back that developed some similar symptoms to what you're seeing. Turned out to be that the OEM Mitsubishi mechanical fuel pump could not keep the bowl in the carb supplied with enough fuel during high power requirements. An electric fuel pump fixed it after some frustrating problem determination. Fuel lines sound like a possibility, also, if they are questionable.

Running the stock Aisin carb right now, but my pump is an Autozone special (Sunday evening fix) so it may be the culprit.
I'm about to go check for cramped or crimped fuel lines, I noticed I have the lurch even in second gear, but only uphill. 60MPH on the straightaway yields nothing.

New plugs are in, and the truck starts, idles, and accelerates smoother than ever.
Timing is fine.

 

[80t0ylc]

Running the stock Aisin carb right now, but my pump is an Autozone special (Sunday evening fix) so it may be the culprit.
I'm about to go check for cramped or crimped fuel lines, I noticed I have the lurch even in second gear, but only uphill. 60MPH on the straightaway yields nothing.

New plugs are in, and the truck starts, idles, and accelerates smoother than ever.
Timing is fine.

Yeah, sounds like you're hot on the trail. Don't know if 60 mph on level ground would kick in the secondaries. But, mashing the skinny pedal down for any length of time, for hills or passing, would demand more fuel than just gassing it from stop light to stop light in the city. Sounds like you got the power initially, but it just starves out for some reason.

 

[Combat Chuck]

Yeah, sounds like you're hot on the trail. Don't know if 60 mph on level ground would kick in the secondaries. But, mashing the skinny pedal down for any length of time, for hills or passing, would demand more fuel than just gassing it from stop light to stop light in the city. Sounds like you got the power initially, but it just starves out for some reason.

That's exactly what happens, I hve powe aplenty at first, but then it all goes away.
I haven't done any hill tests yet since the plugs, but I'll see.

Plug #4 was doing the Quasimodo: big ol' lump of ash on the side of the electrode, so maybe that was part of the issue.

 

[Combat Chuck]

Alright, just drove the truck out to work tonight, and all's well, the few hills I pullled were fine, no missing. I even passed a car, secondaries wide open, no backtalk from the motor. I think the plugs were the source of the issue.