Helppppppppppp 95 yukon surge at idle after 10mins

[cburns002]

Help i have a 95 yukon that has been running fine.. Recently replaced fuel filter and egr valve. And done a complete tune-up.. Started to idle krazy with surges.. After it sits a few days its fine... Wut can it be.... Checked for vaccumm leaks.. Good fuel pressure....

 

[BigWheelinBubba]

I would guess IAC (idle air control) or possibly a bad fuel pressure regulator.
Also maybe a throttle body gasket leak as the bolts on my old truck actually backed out and were finger tight at one point. Changed the TB gasket and was good.

 

[cburns002]

Ty will check those out also..

 

[SunlitComet]

well by 10 minutes you would be in closed loop mode so examine the data on iac control and O2 outputs.

 

[retorq]

It's a 95, light it on fire.

 

[cburns002]

Well changed the iac and still the same thing.... Any other suggestions beside "setting it on fire" lol

 

[SunlitComet]

Did you get it to relearn too?

 

[cburns002]

yes... now if i hold the pedal at 2000 rpm to idle it will start to surge like its not getting any gas. the same thing when i try to drive the truck...

 

[SunlitComet]

how and where did you measure fuel pressure and what was the reading?

 

[cburns002]

dropping it off tomorrow at shop so they can check the fuel pressure.. was trying my best to do whatever i could myself b4 taking it to someone else

 

[retorq]

Can't really check the FP on these units easily at home, that is what mine sounded like then I had a pin hole in the hose between the pump and the tank outlet though ...

 

[cburns002]

Well have changed the iac, egr, fuel filter, fuel pressure regulator and complete tune-up.... Checked for vaccumn leaks (none found)..... Slide underneath the truck and the fuel lines are rusty.. Trying to do everything and anything b4 i have to drop the tank.. Any suggestions....... ??????????

 

[SunlitComet]

how about answering my last question please? and are these lines leaking?

 

[cburns002]

lines are not leaking at all.. i have no way of checking the fuel pressure

 

[BigWheelinBubba]

Sounds like rust buildup in the injector pods.
Next step, since you sound a little challenged in the repair dept. is to get a new fuel line ran and get a set of injectors off of ebay or something. Might even get a whole new or gently used tbi unit.

 

[retorq]

Since it's at the shop he should probably just let them fix it at this point and maybe post back with their findings.

 

[SunlitComet]

wait if you had no way of checking pressure why did you seem to imply it was good in your first post? at any rate leave it to the shop in its entirety since it is already there.

 

[cburns002]

Well have gotten the truck back and after changing fuel pump and sending unit.. Feed line to the filter, new strainers and line... Still having the same problem................................................... The shop had it for two weeks and still cant figure out the issue............... Hellllllllllppppppppppppppppppppppppp

 

[ezdaar]

So you paid out the ass for some shop to swap parts that was perfectly fine and your OK with that..


Since this got missed on the first page.

Have you checked you O2 sensors?! Do you have any Pre O2 sensor exhaust leaks?

 

[SunlitComet]

yeah right.