EGR Valve / fuel system HELP

[psynaut]

Ok.....Figure this one out.

A while back I found hole rusting in my fuel tank, this caused water to get into my fuel. My truck stared to run real rough. so I replaced the tank and flushed out my fuel lines. I replaced the fuel filter twice, as I found that is what just full of rust from the tank.
Well, the truck ran fine for a day, them started running rough again with major hesitation. I pulled off my Fuel injectors and Pressure regulator and gave both parts and there areas in the intake housing a good cleaning. This seemed to help a bit.
I decided just to check out a few more things.
I ended up pulling the Vacuum line off my EGR value and plugging it. Surprisingly, this fixed 90% of my problems, the truck runs way better and with only a little hesitation.
So I pulled of the EGR value, cleaned the hell out of it. After reconnecting the vacuum line to it, the truck started to run like crap again.

Here's what I don't get .....logic would say that my problem would be in the injectors or something else related to fuel intake cause of all the rust and water that got into my system. So why is plugging my EGR valve fixing most of my problems?

Anyone have any ideas?????? Please

[OverBoardProject]

just a guess, but a vaccum leak right in the EGR

[sector95]

The valve itself has gone bad. Either it has a leak in the diaphragm (as was suggested by Overboard or it dumps too much exhaust gas into the intake manifold due to an internal failure. I had to replace the one on my '85.... the P.O. had disconnected it (he also told me when I bought it to use premium gas because it pinged on regular..... surprise, surprise). When I reconnected the EGR vacuum line (the truck had to pass emissions testing) the engine would die as the valve would open, even at idle. Non-ECM controlled EGR valves are not too expensive... mine was $35-$40 at NAPA.

mike

[robmoss00]

There is a recall on the EGR valves. I wrote a letter to the Chevy manufacture because I have replaced mine 2 times, they payed to take it to there shop and have a new one put on.

[OverBoardProject]

Not likely with a 91, but it's possible

[TRACYCULBERSON]

Originally Posted by psynaut

Ok.....Figure this one out.

A while back I found hole rusting in my fuel tank, this caused water to get into my fuel. My truck stared to run real rough. so I replaced the tank and flushed out my fuel lines. I replaced the fuel filter twice, as I found that is what just full of rust from the tank.
Well, the truck ran fine for a day, them started running rough again with major hesitation. I pulled off my Fuel injectors and Pressure regulator and gave both parts and there areas in the intake housing a good cleaning. This seemed to help a bit.
I decided just to check out a few more things.
I ended up pulling the Vacuum line off my EGR value and plugging it. Surprisingly, this fixed 90% of my problems, the truck runs way better and with only a little hesitation.
So I pulled of the EGR value, cleaned the hell out of it. After reconnecting the vacuum line to it, the truck started to run like crap again.

Here's what I don't get .....logic would say that my problem would be in the injectors or something else related to fuel intake cause of all the rust and water that got into my system. So why is plugging my EGR valve fixing most of my problems?

Anyone have any ideas?????? Please

On these fuel injected trucks s-10 especially i dont under stand why they even need the egr valve.I had a 91 s-10 that i bought new in sep . of 1990 . I was young then and was doing some mods .The guy who helped me with this and many other projects and by the way i have seen no other with this guys knowlege he also races for mazda motor sports .Anyway he blocked off the egr valve on this truck and it helped its performance so i would block off the egr with a plate or somthing like a piece of steel or aluminum and just drive it and see how it performs . If it does well i would leave it blocked off

[OverBoardProject]

My carburated 2.8L had the EGR disconected whae I got it, and I left it that way when I rebuilt the motor.

It works great, but I don't have a computer telling it not to.

[TRACYCULBERSON]

Originally Posted by OverBoardProject

My carburated 2.8L had the EGR disconected whae I got it, and I left it that way when I rebuilt the motor.

It works great, but I don't have a computer telling it not to.

Well the 91 i was telling you about had a computor and i had no trouble .It was the early edition of the 4.3 vortec with a trottle body fuel injection .It had under drive pulleys a hypertech chip with stock exhaust . I dont think there was any mods but the chip and the pulleys and i had no problem with it after the egr was blocked . I would still try it