Rabbit
Junior Member
- Joined
- Dec 30, 2011
- Posts
- 4
- Reaction score
- 0
- Location
- Maricopa, AZ
- First Name
- alex
- Truck Year
- 1985
- Truck Model
- C20 Suburban
- Engine Size
- 454
Well, first post here. I have an 85 C20 Suburban Silverado (originally a CA car) with a 454. It has an edelbrock 1407 to replace the california computer controlled carb, which the previous owner had "upgraded" by making a spacer out of plywood, which leaked like a sieve and got 3 mpg.
I mounted the new carb, cleaned up the fuel leaks, removed 3.4 miles of unnecessary vacuum hoses, 40lbs of unnecessary emissions controls (before you say anything- I'm in an area of AZ that has no emissions testing), got the carb idleing "well enough", and have been driving it daily for a few months.
Issue is this- Heading up the 87N out of Phoenix, which is ridiculously steep and climbs to 6700ft (my artea is at 1200ft), I started getting popping/shimmying/loss of power etc., to the point I had to pull over every 5 miles or so, let it idle for 5 minutes, then continue another 5 miles. Rinse, repeat.
It seemed to clear up at lower elevation, so I wrote it off as vapor lock or other fuel starvation. However, it has started to miss/pop under load even around town when accelerating. It's not a constant thing, some days it runs great, other days it wheezes like at asthmatic getting to 35mph.
In anticipation, I bought new plugs and wires, and will be checking the timing/tuning the carb. What should I aim for timing wise? Is the stock fuel pump okay for a 750cfm carb? The california one seems to have been a 500cfm one- Are the posts I am finding about cal trucks having hotter plugs correct? I'm normally a classic beetle guy (I have a 67 baja), but this is my first proper square body, and I want to do it right. (actually the second, I had an 82 K20 longbed... that was stolen a month after purchase. But that's neither here nor there)
I know this is alot of questions, but again... Brand new to this thing. Any help would be awesome.
I mounted the new carb, cleaned up the fuel leaks, removed 3.4 miles of unnecessary vacuum hoses, 40lbs of unnecessary emissions controls (before you say anything- I'm in an area of AZ that has no emissions testing), got the carb idleing "well enough", and have been driving it daily for a few months.
Issue is this- Heading up the 87N out of Phoenix, which is ridiculously steep and climbs to 6700ft (my artea is at 1200ft), I started getting popping/shimmying/loss of power etc., to the point I had to pull over every 5 miles or so, let it idle for 5 minutes, then continue another 5 miles. Rinse, repeat.
It seemed to clear up at lower elevation, so I wrote it off as vapor lock or other fuel starvation. However, it has started to miss/pop under load even around town when accelerating. It's not a constant thing, some days it runs great, other days it wheezes like at asthmatic getting to 35mph.
In anticipation, I bought new plugs and wires, and will be checking the timing/tuning the carb. What should I aim for timing wise? Is the stock fuel pump okay for a 750cfm carb? The california one seems to have been a 500cfm one- Are the posts I am finding about cal trucks having hotter plugs correct? I'm normally a classic beetle guy (I have a 67 baja), but this is my first proper square body, and I want to do it right. (actually the second, I had an 82 K20 longbed... that was stolen a month after purchase. But that's neither here nor there)
I know this is alot of questions, but again... Brand new to this thing. Any help would be awesome.