Jond983 Posted April 28, 2007 Report Share Posted April 28, 2007 i have to run 93 octane in mine, i ran 91 by mistake last week and the motor was pinging it's ass off Quote Link to comment Share on other sites More sharing options...
brobradh77 Posted April 28, 2007 Author Report Share Posted April 28, 2007 (edited) well if its that low on fuel press most likly it is the pump. but i was assuming you had to pay 400 for it , warranty always kicks ass. but if you were in the boat with no warranty a walbro upgrade isnt a bad idea. Definately a good idea and one i never would have thought about Thanks. I just looked it up so I could relay prices of this pump if someone has to replace it and not under warrany. Like I said I have ran both and we have 93 here or 87 and never had any pinging or other problems at all until the higher octane but I am not convinced it was just a fluke. Of coarse running 87 on a high octaane tune may allow me to run leaner and leaner = faster Edited April 28, 2007 by brobradh77 (see edit history) Quote Link to comment Share on other sites More sharing options...
Barney Posted April 28, 2007 Report Share Posted April 28, 2007 If your fuel pressure is changing like that but returning to a higher level, I would suggest changing out your fuel filter first. You may have some grime in there from the lower level gas. I have always run 93 and never had an issue but also never run below 1/4 tank. You may be worried over nothing on this mechanics info. Not to say he is a bad person or chevy is not telling him this but anyone can be wrong. Good luck Quote Link to comment Share on other sites More sharing options...
zanis520 Posted April 28, 2007 Report Share Posted April 28, 2007 running low on gas is espeacially hard on you intank pump. it will cause its life span to shorten quickly i never run with less than a 1/4 tank. also why not replace your fuel pump with a walbro 355? its 100 bucks and flows more fuel. i never let mine go below 1/2 Quote Link to comment Share on other sites More sharing options...
perk03z06 Posted April 28, 2007 Report Share Posted April 28, 2007 This is why I asked about fuel level ... everything CHASE has mentioned, running the fuel pump not completely submerged (less than 1/4 tank) will cause it to run hot, and cause it to prematurely fail, especially if you do it often. If you keep 1/4 tank or more, your pump will be submerged in the cooler gasoline, and it will run at a lower temperature. Very important w/ GM pumps .... they need to be kept cool ... submerged. I've run 89 and 93 in mine w/ no hiccups thus far ... 89 mainly for hwy cruising and 93 when I know I'm not going on long trips. The difference between running the different octane ratings is the chance that the gasoline will prematurely combust under pressure, causing the *ping* or *knock* that is typically heard. Which is why higher compression engines require higher octane fuel. The higher the octane rating, the less chance there is of the gasoline igniting prematurely. This would in no way effect the fuel pump ... what the dealer, or service writer told you is Quote Link to comment Share on other sites More sharing options...
Badkarma Posted April 28, 2007 Report Share Posted April 28, 2007 This is why I asked about fuel level ... everything CHASE has mentioned, running the fuel pump not completely submerged (less than 1/4 tank) will cause it to run hot, and cause it to prematurely fail, especially if you do it often. If you keep 1/4 tank or more, your pump will be submerged in the cooler gasoline, and it will run at a lower temperature. Very important w/ GM pumps .... they need to be kept cool ... submerged. I've run 89 and 93 in mine w/ no hiccups thus far ... 89 mainly for hwy cruising and 93 when I know I'm not going on long trips. The difference between running the different octane ratings is the chance that the gasoline will prematurely combust under pressure, causing the *ping* or *knock* that is typically heard. Which is why higher compression engines require higher octane fuel. The higher the octane rating, the less chance there is of the gasoline igniting prematurely. This would in no way effect the fuel pump ... what the dealer, or service writer told you is I would tend to agree, octaine simply put is a resitstance to detination,the higher the rating, the higher the resistnace to detination... as we all know. The flow characteristics between mid grade and high grade I would think to be so similar as the fuel pump itself wouldnt know the diffrence between the two. So I have no idea at all why they would put a bullitin like this out. Unless it is somthing in the additve packages of diffrent types of gas being sould trough verious vendors causeing the pump to fail from some type of internal damage. Keeping the pump itself cool those is paramount, as anyone running an aftermarked race type pump can attest. Myself I wouldnt call the 91 spew we get here at the pump in cali high test by any stretch of the term. If i recall it calls for 92 or higher with my truck, though I would have to check the manual again to make sure. Seeing all the stuff they delute our gas with here in cali, running mid grade or regular would seem to me to be brutalizing your motor. Higher octaine= slower more complete burn. As far as the fuel filter goes, changing it often is like chicken soup, it sure cant hurt. But I belive mine is in the tank so I may be SOL on that. I would like to see the txt of this so called bulletin, Can some one post it if and when I comes out?? Quote Link to comment Share on other sites More sharing options...
[email protected] Posted April 28, 2007 Report Share Posted April 28, 2007 I seem to find that higher octane helps my g.m. I also had a reg. silverado that didn't perform well because of low octane. I let the fuel tank get below 1/8 of a tank and burnt out the fuel pump because the "previous owner ran 87" and sludge in the engine got sucked into the fuel pump, so said auto man. I wouldn't risk anything lower than 93 it adds up to less money than replacing the engine. just my .02. but what do I know. Quote Link to comment Share on other sites More sharing options...
brobradh77 Posted April 28, 2007 Author Report Share Posted April 28, 2007 (edited) The fuel filter is in the tank right? I did a search and Chase mentioned that they are good for 100K miles w/o service. My truck has 9K miles on it. I am not completely convinced that I may have got some bad gas with water in it so I purchased a fuel cleaner yesterday to see how that helps after a day or so of driving for me thats about 10 miles..lol If there is water in the tank and the fuel pump went out GM wont warranty it. Does anyone have a link to where I can purchase a Walbro fuel pump and is it a direct replacement or do I need a kit and is the thing complete as the stock pump just produces more flow? I have found a few sites but noone go over the year 98 for a chevy truck mine is an 06 Thanks Edited April 28, 2007 by brobradh77 (see edit history) Quote Link to comment Share on other sites More sharing options...
RacerJJ Posted April 28, 2007 Report Share Posted April 28, 2007 The fuel filter is in the tank right? I did a search and Chase mentioned that they are good for 100K miles w/o service. My truck has 9K miles on it. I am not completely convinced that I may have got some bad gas with water in it so I purchased a fuel cleaner yesterday to see how that helps after a day or so of driving for me thats about 10 miles..lol If there is water in the tank and the fuel pump went out GM wont warranty it. Does anyone have a link to where I can purchase a Walbro fuel pump and is it a direct replacement or do I need a kit and is the thing complete as the stock pump just produces more flow? I have found a few sites but noone go over the year 98 for a chevy truck mine is an 06 Thanks The only filter that I know of is located on the driver's side on the frame rail right about under the rear door. Get under there, you'll see it! Quote Link to comment Share on other sites More sharing options...
04CHASE Posted April 28, 2007 Report Share Posted April 28, 2007 The only filter that I know of is located on the driver's side on the frame rail right about under the rear door. Get under there, you'll see it! no he wont . the 04+ trucks have the fuel filter in the tank . returnless systems dont have an external fuel filter. Quote Link to comment Share on other sites More sharing options...
brobradh77 Posted April 28, 2007 Author Report Share Posted April 28, 2007 Will this one work? http://cgi.ebay.com/ebaymotors/WALBRO-255-...sspagenameZWD1V Quote Link to comment Share on other sites More sharing options...
ZZebes Posted April 29, 2007 Report Share Posted April 29, 2007 I hate to hijack your thread but i have a quick question. I am really confused, i had my truck up on a rack yesterday for the first time where i can get a good lay of the land and i looked t my fuel lines and i have 2 i am guessing send and return, BUT i have a 2006 which i though had a returnless fuel system. Somebody tell me i'm not going insane Quote Link to comment Share on other sites More sharing options...
Badkarma Posted April 29, 2007 Report Share Posted April 29, 2007 I hate to hijack your thread but i have a quick question. I am really confused, i had my truck up on a rack yesterday for the first time where i can get a good lay of the land and i looked t my fuel lines and i have 2 i am guessing send and return, BUT i have a 2006 which i though had a returnless fuel system. Somebody tell me i'm not going insane Now you have me curious. I'm going to have give the truck a good look over this weekend. Quote Link to comment Share on other sites More sharing options...
04CHASE Posted April 29, 2007 Report Share Posted April 29, 2007 ones a feed line and one is a line for evap . it takes the fuel fumes back to the intake so they wont go directly in the air, its an emissions thing. Quote Link to comment Share on other sites More sharing options...
ZZebes Posted April 29, 2007 Report Share Posted April 29, 2007 oh ok. so a return system has 3 hoses??? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.