Need help with my 99 blazer please

[NCTyphoonKid]

Hey all having some issues with the 99 I just a motor in. It is surging while going uphill I can watch the tach jump back and forth from 1500-1800-2000ish rpm. Seems to do it between 45-55 mph. I have no vacuum line diagram so I'm unsure if its vacuum related. Its a 99 S10 Blazer 4x4 LT. None of the orange indicator lights are on for the push button 4x4 either. Also while driving it I had the codes PO410,PO171, and PO174 come up. Also what is this it has a couple vacuum lines as well. Like I said very unsure how the vacuum lines are suppose to go.

You must be registered for see images attach

 

[bucket]

That stuff under the radiator is some kind of emissions package, only seen a handful of them in Ohio before. 171 and 174 are lean codes aren't they? I don't remember for sure. But it does sound like a vacuum leak. Have the intake gaskets been done yet?

 

[MadOgre]

Lean would explain the surging!

 

[NCTyphoonKid]

No the intake gaskets haven't been done only has 100k on the motor but I have no vacuum diagram to go by to figure out how they go

 

[350runner]

My brother in-laws 97 did the same thing. Ended up being the coolant sensor. Well his father in-laws broke the dang connector and didn't say anything.... We went through changing the fuel pump...omg that was horrible. Found out the two door and four for have different pumps the hard way...

Sent from the dust in front of you!

 

[NCTyphoonKid]

I don't think it's the intake gaskets the codes literally just popped up so I'm pretty sure it's because I can't figure out the vacuum lines. Also the part in the picture is called a secondary air pump and is one of my codes and it also has two little vacuum lines that I have no clue where they go

 

[NCTyphoonKid]

My brother in-laws 97 did the same thing. Ended up being the coolant sensor. Well his father in-laws broke the dang connector and didn't say anything.... We went through changing the fuel pump...omg that was horrible. Found out the two door and four for have different pumps the hard way...

Sent from the dust in front of you!

The coolant sensor on the drivers side head?

 

[350runner]

IIRC...The coolant temp switch is on the drivers side head. The temp sensor is on the front of the intake next to the t stat/ top radiator hose.

Sent from the dust in front of you!

 

[NCTyphoonKid]

IIRC...The coolant temp switch is on the drivers side head. The temp sensor is on the front of the intake next to the t stat/ top radiator hose.

Sent from the dust in front of you!

Alright I'll take a look at that do you have any idea about the vacuum lines

 

[350runner]

I will admit at first when the surging and bucking like a bull started with his blazer I really thought it must of been a bad vacuum leak. Looked for days with no luck. Then i said it must be the fuel pump... Nope. Then i said Google 97 blazer surging problem. Sure enough this and the ignition switch showed to be a known issue. More so the ignition switch. Since he had already changed the column due to an accident he had we went straight to the temp sensor only to find the connector was broken the whole time... Ugh. Duck taped it back on temporally and that blazers vortec ran like a scaled ape.

Sent from the dust in front of you!

 

[NCTyphoonKid]

I will admit at first when the surging and bucking like a bull started with his blazer I really thought it must of been a bad vacuum leak. Looked for days with no luck. Then i said it must be the fuel pump... Nope. Then i said Google 97 blazer surging problem. Sure enough this and the ignition switch showed to be a known issue. More so the ignition switch. Since he had already changed the column due to an accident he had we went straight to the temp sensor only to find the connector was broken the whole time... Ugh. Duck taped it back on temporally and that blazers vortec ran like a scaled ape.

Sent from the dust in front of you!

Alright I'll take a look I just hate that I have 2-3 vacuum lines going nowhere just unhooked

 

[350runner]

Check the back lines they probably go down to the frame rail. I would think if you had that Many going no where the engine would stumble from a stop. Of course every situation is different.

Sent from the dust in front of you!

 

[NCTyphoonKid]

True it does have some hesitation but not to bad

 

[350runner]

When this surging occurred it would happen. At idle, from a stop, and while driving.

Sent from the dust in front of you!

 

[NCTyphoonKid]

When this surging occurred it would happen. At idle, from a stop, and while driving.

Sent from the dust in front of you!

I think I have the vacuum lines done correctly now I still need to find the transfer case vacuum switch so I blocked that line off and replaced a couple that were very brittle. I'm going to go get some gas for it and see what it'll do on this test run. It doesn't seem to be hesitating now.