OK, I've been working on the truck for awhile, but it still seems real weak down low....I mean I thought the L98 was supposed to be a torque monster, especially down low.

I put on a new fuel filter, afpr, ran injector cleaner through it, ran some "sea foam" through it, new plugs, timing set to 8*. I have headers too. Checked for vacuums leaks.

I have a new o2 sensor, but haven't put it in yet.

Right now I have 87 octane gas in it, but will switch to 91 next tank (don't drive the truck very often).

I know my truck is not set up to be fast (4000 lbs, "stock" converter, 3.08 gears) but the smaller carbed 327 I had in it before this with a TH350 (higher first gear) had more torque off idle than this thing does. I can't even get the tires to spin from a stand still. (275/50/17)

What else can I look for, or change?

 

What cam? What fuel pressure? Any aftermarket exhaust? Something is not right if an L98 can't ignite rubber in a pickup, even on 87 octane.

 

stock cam, fuel pressure at 48psi,

Dual 2.5" custom exhaust with 40 series flows (no crossover )

Oh, and I just had a performance rebuild on the 700r4

that's I was thinking

 

Bad 02 sensor and EGR valve can make it 'chug' off the line. Those gears and a heavy *** truck don't help either.

 

Correct me if I'm wrong, but isnt a stock L98 supposed to run "best" on 91 and higher octane? My 88 GTA seems to chug a little with 94 octane but loves 91.......don't have the manual to see what GM recomended to run in the L98 back then.

 

I run 93, and if I run anything below, I can feel it big time.

 

Assuming you have a l-98 in a truck did you put tuned port on it as well? Have you had your injectors flow matched? Do you have a cold start injector, does it leak? Is the knock sensor connected properly? Have you adjusted the throttle position sensor? Has the fuel system been professionally flushed? I have 305 tuned port in the same position as your truck wont burn them off of the line. I think my o2 sensor may be defective as well so that is a very logical cause, and whoever said egr that is another system to examine. 305s have soft cams that are notorious for going weak and wear away did you examine the camshaft for wear? Do you have anymore symptoms? Mine lost 1000 rpm's it will not turn past 5,000 rpm's anymore. It used to pulll strong all the way to 5,700 rpms.

 

Hey fellas, I disconnected my cold start injector....electricaly when I upgraded to 89 code, do I still need to remove the fuel feed to it? I do not want the damn thing to leak or waste fuel when I do not even use it.

 

I believe there are many posts on doing this. I have never done it so I can not help too much, but I do believe people were taking the injector out entirely. I believe they put freeze plugs in place of the injector, and fuel line with some type of sealant. That shuold plug everything and clear up some space on the driver side valve cover.

 

There's a delete kit that accell makes to remove the cold start injector. I bought it off summit. P/N ACC-74820 if the link doesn't work.

 

What i'm trying to find out if there is any difference in engine performance if I just leave my cold start inj. disconected electricaly or if I remove the thing completely?

 

Long as the injector isn't leaking fuel, I don't see how you would get any performance improvement by removing it. Sure it cleans things up a bit without it but also lightnens your wallet.

 

Cold start injectors are commonly known for not sealing right, and leaking extra feul down into the engine. So if you leave it on the engine you are only wasting space, and leaving room for more problems even if it is fine now.

 

I gained 2-3 more mpg city (55 mph with stop lights every mile or so) after I replaced my injectors and plugged the cold start. I can't point my finger at one or the other, but I know that both were most likely not working as well as they otherwise could be.

 

I know there is a plug kit that you can buy from summit for 50 or so bucks, but can I fabricate or buy some sort of freeze plug after removing the cold start injector? I do not want to spend cash to get rid of something.