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5.7 Vortec hesitation when warm

Redneck_nick_z71

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Redneck_nick_z71 Enthusiast

Redneck_nick_z71

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Hello everyone,

so about 2 weeks ago I got my intake gasket replaced and after I got the truck back it had a terrible misfire Which they took care of but it seems to run like crap since then (he said to drive some and then take it back if it’s still doing it) but I noticed at stop signs when I go to take off it falls on it’s face and then floors it basically and if you rev it it seems to almost die, you can physically hear the motor stop for a second and all the lights dimmer and then it revs up. also the other day while driving it you could hear the motor stop 3 different times. It idles fine and the problem only happens when it is completely warmed up. I just cleaned the MAF and I’m letting it dry. Hopefully this will fix it. Any information on what would be causing this would be appreciated. Thanks, Nick 

P.S here she is, pretty good for only being 15 I’d say 

ArcticFoxCJ Enthusiast

ArcticFoxCJ

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49 minutes ago, Redneck_nick_z71 said:

Hello everyone,

so about 2 weeks ago I got my intake gasket replaced and after I got the truck back it had a terrible misfire Which they took care of but it seems to run like crap since then (he said to drive some and then take it back if it’s still doing it) but I noticed at stop signs when I go to take off it falls on it’s face and then floors it basically and if you rev it it seems to almost die, you can physically hear the motor stop for a second and all the lights dimmer and then it revs up. also the other day while driving it you could hear the motor stop 3 different times. It idles fine and the problem only happens when it is completely warmed up. I just cleaned the MAF and I’m letting it dry. Hopefully this will fix it. Any information on what would be causing this would be appreciated. Thanks, Nick 

P.S here she is, pretty good for only being 15 I’d say 

I'm assuming the MIL light isn't on since you didn't mention it.

 

By intake gasket I'm also assuming you mean the intake manifold gasket.

 

What engine are we talking about?  If the distributor had to be removed (assuming that model has a distributor) to get the manifold off, I'd start there.  Check ignition timing and make sure any electrical connectors and/or vacuum hoses are still attached.  What you're describing sounds like a timing issue to me.  Hard to say more without knowing the specifics of the vehicle and engine though.

Redneck_nick_z71 Enthusiast

Redneck_nick_z71

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1 minute ago, ArcticFoxCJ said:

I'm assuming the MIL light isn't on since you didn't mention it.

 

By intake gasket I'm also assuming you mean the intake manifold gasket.

 

What engine are we talking about?  If the distributor had to be removed to get the manifold off, I'd start there.  Check engine timing and make sure any electrical clips and/or vacuum hoses are still attached.  What you're describing sounds like a timing issue to me.  Hard to say more without knowing the specifics of the vehicle and engine though.

My bad I put it in the title and not the post, it’s a 5.7 Vortec 

ArcticFoxCJ Enthusiast

ArcticFoxCJ

Posted
Posted
Just now, Redneck_nick_z71 said:

My bad I put it in the title and not the post, it’s a 5.7 Vortec 

OK cool.  Does it have a distributor?  If so, I'd start there.  check/adjust ignition timing.  If it's WAY off then the distributor might not have been properly reinstalled if it had to come off with the manifold)

 

If that's okay (or there is no distributor) then I'd look at other stuff in the vicinity of the manifold.  Bad sensors, like a TPS or airflow meter would likely trip the MIL light (for other reasons than an O2 sensor) so odds are you're okay there.  I'd next check the fuel injectors and make sure everything's on tight and clean.

Redneck_nick_z71 Enthusiast

Redneck_nick_z71

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22 minutes ago, riverbanks said:

Code #?,and was it there before work was performed?

It was the P0101 or something like that. Whatever the 02 sponsor is. And yes it was there before the work. 

ArcticFoxCJ Enthusiast

ArcticFoxCJ

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Posted
3 minutes ago, Redneck_nick_z71 said:

It was the P0101 or something like that. Whatever the 02 sponsor is. And yes it was there before the work. 

The O2 sensor(s) sits in the exhaust pipe and measures the amount of oxygen in the exhaust gas to help the ECU regulate the fuel mixture.

Redneck_nick_z71 Enthusiast

Redneck_nick_z71

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54 minutes ago, CamGTP said:

P0101 is  MAF code.

Well I guess that’s what I get for listening to someone. It didn’t act up until now though. Well hopefully it just needed cleaned. I guess we’ll find out tomorrow. 

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