[jimmykicker]

Hey, just want to touch base back with everybody about my 4bbl conversion that I was having some issues with some time ago. I had a shoddy 2bbl Rochester that got my truck 14mpg or less regardless of how you drove it or where you drove it. 14 flat. The truck took almost 24 seconds to achieve 60mph. I received this response from another member

Let's see, you took off a 2 barrel and put on a 4 barrel and expect better gas mileage? Now that I'm done laughing, try slightly smaller jets, but if it starts pinging go back up. Run a heavier spring in the secondaries. Run the idle stop as low as possiable, even if it means opening up the secondary stop a little. Make sure your fuel pressure isn't too high and you have a good inline fuel filter, it doesn't take much dirt to get the fuel to bleed past the needle and seat and make the fuel level in the bowls too high. Make sure you have a good tuneup and some extra spark will help, be it, a better coil or if you can swing it an ignion box

The truck achieves 60mph now in about 15 seconds which is a huge improvement in perfromance.

Well, I did change the secondary spring to the next stiffest one, and might go to the stiffest one yet, tuned up the truck and replaced every ignition part except the distributor itself. I now get 16 in town delivering food and approach 20mpg on the highway. Hmm. that's a 43% increase on the highway and 14.3% increase around town improvement and it hauls a** to boot!!! Let's see, I took off a 2 barrel and put on a 4bbl and expect to get better gas mileage? Now that I'm done laughing......

INF

 

[joed]

Well, that's great.
But like I said, I have that orig rochester 2se and I've been getting 18city/21hwy after a rebuild/cleaning/tuning. Nearing 300k (orig engine/tranny) and it's still getting the sticker labeled mpg back when it was bought.

People knock these 2.8's, but 've never seen such a die hard....not at nearing 300k miles at least.

The real issue was the ignition - now THAT needed attention.

 

[ezrollin]

I had the offy manifold with a 390 holley carb and a 260 cam on my old 83 / 2.8 2wd blazer with 4sp / 3:08 and got 20 mpg at expressway speeds.Some 4 bbl carbs do get better mileage than some two bbl carbs because the primaries on the 4's are smaller than the two bbls and you'll spend most of the time on the primaries.Get instr. on tuning the holley for best results.

 

[cbolt]

Hey, just want to touch base back with everybody about my 4bbl conversion that I was having some issues with some time ago. I had a shoddy 2bbl Rochester that got my truck 14mpg or less regardless of how you drove it or where you drove it. 14 flat. The truck took almost 24 seconds to achieve 60mph. I received this response from another member



The truck achieves 60mph now in about 15 seconds which is a huge improvement in perfromance.

Well, I did change the secondary spring to the next stiffest one, and might go to the stiffest one yet, tuned up the truck and replaced every ignition part except the distributor itself. I now get 16 in town delivering food and approach 20mpg on the highway. Hmm. that's a 43% increase on the highway and 14.3% increase around town improvement and it hauls a** to boot!!! Let's see, I took off a 2 barrel and put on a 4bbl and expect to get better gas mileage? Now that I'm done laughing......

INF

I told you so. Mine has always done better with the 4bbl.

 

[jimmykicker]

Well, that's great.
But like I said, I have that orig rochester 2se and I've been getting 18city/21hwy after a rebuild/cleaning/tuning. Nearing 300k (orig engine/tranny) and it's still getting the sticker labeled mpg back when it was bought.

People knock these 2.8's, but 've never seen such a die hard....not at nearing 300k miles at least.

The real issue was the ignition - now THAT needed attention.

Nah, even when I put the truck together back in 1997, I used all new ignition parts. I still got crummy mileage. It should be noted that it still got poor fuel economy after I swapped the new ignition parts in after I replaced the carb with the Holley back in November. I could tell little to no improvement although it did run better. I also replaced a cracked head and it stll got about the same. The biggest improvement occured when I changed the secondary spring to a stiffer one. I might soon put in the stiffest one and see if it comes up some more. I also ran a couple of tanks of super in it which seemed to help some although I don't know why it would.

Maybe it's the way I drive, but I have never had a vehicle that got the "sticker" mileage. It always was worse so I take that with a grain of salt. I drive almost exculusively in town in serious stop and start, (I deliver food in it for a living) so I expect it to not be great. I almost cried when it got 19.5+ on the highway! I think 16 is great for in town for that truck considering the weight and style of driving.

Worth every penny and every bit of effort. Don't knock it till you try it!

 

[joed]

Well, I'm saying MY ignition needed work.

But...umm, no man I'm not gonna try it. The thing's nearing 300k orig eng miles on it.
No need to spend $ on anything there and futzing with a new carb if I'm still getting 18mpg city with a paid for 85 4x4 and the orig 2se Ya know?
Remember, it's a 4x4. 18mpg city for an 85 4x4 is great.

I bet it helps your acell though (but again, I have no need to try chirp the thing out the gate or beat another car off the light ...to get to the next light faster).
if I were in my teens i might care about that, but not now. I'm just amazed the thing is still running right. for it's age
Just seeing how long she'll last is more important.

So I understand your explaining your carb purchase - and only YOU know if it was time to do so....but in GENERAL, the roch 2se properly tuned and revitalized can and is getting adequate mpg...which is why I replied (way back when) as far as the rochesters being "bad carbs".... they aren't (and all the old school carb shops told me the same)... but they are finicky and tougher to dial in for your engine/situation. There I agree.

I'm glad a new carb solved YOUR problem...but others should know that not all 2se carbs are crap. It varies on wear/repair knowledge...and in your situation it sounds like you couldn't tune that 2se (shot carb), so a holley was the best move.

Unless it's completely shot, I just don't see a reason to add a holley or any other carb (unless you're totally rebuilding an old 1st gen I guess).

 

[jimmykicker]

Joed, I am curious however about the performance of the engine. My truck does 0-60 in 15 which isn't blistering fast by any means. My truck was so damn slow (23.5 sec) it was in my opinion fairly dangerous. These nuts over here really don't drive too well and the extra oomph really comes in handy sometimes.. The reliability issues and fuel economy deal you talk about is right on. I agree. That carb was worn out no question! I have never rebuilt a carb and digging into it wasn't really on the agenda. Buying a rebuilt one was nearly $300. THe Holley was $320. See what I mean? Whatever works fer ya bud. Say how long before 300K? I got 253 and change. I was out at the junkyard the other day and the only s-10 (that had 100K readable mileages) was 240. Some as low as 170K. That's a shame. Just goes to show what happens when people don't take care of stuff like we do!

Just kidding! Changed over to 94 core support so I could properly install a 92 grille! It's already back together! :haha: :rotf: