Holley Tbi 670 review and smog pump delete

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K5Blazerboy87

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Hey guys so I'm taking the engine out of my 87 k5 im keeping it fuel injected because people are telling me not switch completely over to a carb So keeping tbi 350 but has anyone ever use the holley tbi 670 ? How is it and also how do you delete smog pump?
 

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I can't say about the Holley TB.

But deleting the smog pump is easy. You just remove it and be happy, lol. If you remove all of the smog pump plumbing and keep the stock manifolds, you just have to plug the hole.
 

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wouldnt it also mess with the way the engine runs as it thinks it is getting fresh air in the mix and its not giving the illusion it is running rich. then the ecm would pull fuel causing a lean condition and make it fart/pop/snort and buck?
 

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Nope, it doesn't know the difference. Fueling is based off of the O2 sensor.
 

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It also doesn't pump much at all. It's a joke really.
 

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What about egr stuff
 

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Nope, it doesn't know the difference. Fueling is based off of the O2 sensor.

I know the egr affects the tune it was causing mine to act up. It will set a code also, possibly causing it to be in limp home mode and get even worse mpg.
 

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I know the egr affects the tune it was causing mine to act up. It will set a code also, possibly causing it to be in limp home mode and get even worse mpg.

Depends on what happens. If the egr is deleted or if the ports plug up, it just sets a code while coasting at speeds of around 55 or higher. If the egr sticks open at all, yeah, it will run like poo poo.
 

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Depends on what happens. If the egr is deleted or if the ports plug up, it just sets a code while coasting at speeds of around 55 or higher. If the egr sticks open at all, yeah, it will run like poo poo.

My egr was plugged an when it would tell it to open the truck would stumble buck then take when I gave it more gas causing the egr to close at highway speeds.
 

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My egr was plugged an when it would tell it to open the truck would stumble buck then take when I gave it more gas causing the egr to close at highway speeds.

So it was sticking then. If the egr is plugged up solid of otherwise blocked off, it's impossible for it to cause an issue. Whether or not the ecm is telling it to open does not matter. The ecm doesn't call for more or less fuel unless the O2 sensor calls for it. When they are sticking, it causes them not to close fully at times, which basically creates a vacuum leak. Which in turn causes stumbling and whatnot.
 

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So it was sticking then. If the egr is plugged up solid of otherwise blocked off, it's impossible for it to cause an issue. Whether or not the ecm is telling it to open does not matter. The ecm doesn't call for more or less fuel unless the O2 sensor calls for it. When they are sticking, it causes them not to close fully at times, which basically creates a vacuum leak. Which in turn causes stumbling and whatnot.

The port in the intake was clogged, if its not allowing the gas back in the o2 wont see the correct change even though it is calling for it resulting in lean condition right?
 

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The port in the intake was clogged, if its not allowing the gas back in the o2 wont see the correct change even though it is calling for it resulting in lean condition right?

Nope. The egr reintroduces small amounts of exhaust into the intake stream, it really has none of the same properties of raw fuel. But the O2 sensor reads the air/fuel ratio and signals the ecm to adjust accordingly. So even if the egr was supposed to be adding fuel to the intake but wasn't, the ecm wouldn't lean it out because it was anticipating added fuel from the egr. The O2 sensor would tell it to do otherwise. But it really doesn't matter anyway, because it's spent gasses being recirculated, not fuel.

The ports can be blocked causing a restriction in flow, but still have flow. The same crap that blocks the ports can make the egr stick and not fully close. This is where the driveability issues come from. The egr valve cannot be open during many conditions.

I've probably explained that horribly. But I do know from experience that a completely blocked egr, onop but closed egr, or deleted egr will not cause a drivebility issue. But will occasionally set an "egr, lack of flow" code under certain driving conditions. And deleting a smog pump will create zero issues at all.
 

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I confirm the removal of the smog pump will not cause any issues. I removed the one from my 87 R10 when I converted to a serpentine system. I left the plumbing since I didn't want to plug all of the holes in the manifold.

The 2 main items that regulate how this trucks operate besides the computer are the O2 and the temperature sensors. I can't tell you how much time I've wasted diagnosing problems with drivability, performance and idle when the temp sensor was the issue.

Now that the system is dialed in I prefer having fuel injection. I wouldn't change to carb.
 

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