How is it possible to run lean on #7 and #8

[IndyBlk5.0]

more fuel it sounds like. I must be running lean... bigger fuel pump time.

 

[saleenx029]

IndyBlk50 we seem to have experienced a similar situation and have many similarities between our motors and the way they are acting. The way I plan on handling it (the lean condition)this time around is with a wideband 02 sensor and a tweecer system (or at least a custom tune) The wideband will tell you when you are really lean and therefore when to let off, until you get a good tune that adds fuel at needed rpms. I din't think the block or heads are bad, invest in tuning and fuel system. Maybe you have a MAF problem. You can identify the lean problem by looking at sparkplugs, and the blown gaskets. When lean, the heat is incredible, and the marks will be obvious. The #8 cylinder tend to run lean because of the intake design. My car was also rich at idle, and lean at high rpm, but that means the whole motor should be lean, not just the #8 cylinder, so how did you figure this?

 

[IndyBlk5.0]

7 and 8 are the last to get fuel on the fuel rail....

 

[IndyBlk5.0]

Well since my machine shop is going to tear it down and rebuild it for free (labor) , i might go with low compression forged pistons and arp bolts throughout. o ringed head gaskets....... change fuel filter, 255 pump, check injector wiring. and have block and heads checked agian for cracks.

 

[5.0Droptop]

I stopped in today and Dan said your rings were hung up again in 2 pistons?

 

[IndyBlk5.0]

come to find out. This was all just abunch of BS. It was a valve smacking a piston problem...

 

[stockhatch]

So it wasnt head gaskets? LOL dam. I guess with an F-cam and milled heads/block its not that surprising. So what are you doing to it to fix it?

AC

 

[IndyBlk5.0]

This is an old thread. The head gaskets were perfect when we pulled the heads off. The combo in sig is what I did to fix it

 

[stockhatch]

Oh cool. So how you liking the new combo?

AC

 

[IndyBlk5.0]

Not in the car yet, will be in 1 week.

 

[Rick 91GT]

So what did the orignal shop say, that stuff should have been checked.

 

[IndyBlk5.0]

The didnt say much at all. It was kindof a kick in their face when they took the heads off when I was there and it wasnt blown. Also, when they pulled out all the pistons, the rings were binding, and there was carbon in the grooves. ALL AFTER 300 MILES!!! The main guy started to say something about getting hot and then just shut up. What can cause carbon in the ring grooves after that short of a time?

 

[dastang2]

I dont care what anyone says, but running too rich will never blow a head gasket, and having too low compression will not create a lean condition. Secondly, like I said before, are you sure your running lean because all you keep saying is that you are blowing head gaskets. Running lean isnt the only thing that blows head gaskets. Lastly, how do you know its the head gasket. I dont see how on Earth you keep blowing gaskets if you keep using new bolts, and everything is decked and true and your torquw specs are right. Obviously, you dont have all the answers needed, and furthermore with gasket blown like symptoms and low compression shared in 2 adjacent cylinders, it sounds more like a cracked head or block. Face the facts. You need to find out if they are really running lean because it sounds like you just guess they are. Have you ever thought, that after assuming something and trying to fix it 3 times, that maybe your original assumptions are wrong. If the engine was just rebuild, and everything is decked and straight and you followed all correct procedures to installing a head,and your electrical is good and your injectors were just rebuilt, your not running lean. I'm going to go with a major crack somewhere.

what i meant to say that if the compression is low due to the rings then the vacuum that sucks the gas and air will be low too therefore causing a lean cylinder, and i was right because of the binding rings.

 

[IndyBlk5.0]

Does anyone know?