Surging Idle/Dying ideas?

[94svtturbo]

Ok. so when my car is trying to sit at idle it surges from about 800 - 1200 RPMs. then it will dip to 600 RPMs and barely recover and a lot of the times it doesnt recover and just dies. I can drive pretty good except for it feels like i have an occasional hiccup while cruising but as soon as i pull up to a light or stop signs it either dies or sits there and surges 'til it dies. Now i have tested the TPS, and IAC, and Have cleaned the IAC. I can unplug the IAC and control the car using the throttle linkage anything above 1200 or so RPMs and it doesnt surge. As i slowly close the butterfly(still using the throttle linkage) it will get to about 1000 - 800RPM range and it starts to surge again. but the fuel pressure is staying constant at 39PSI.

Any ideas?

 

[pp_puncher]

vac. leak for sure

 

[94svtturbo]

vac. leak for sure

Yeah. i am still trying to find out if thats it. i have looked tried to find one but havent had any luck yet

 

[pp_puncher]

shit, p-town where are you at?

 

[94svtturbo]

****, p-town where are you at?

Hell yeah. I live in milwaukie but my car is at my buddy's garage we just built at his house off of 82nd and foster.

oh yeah BTW my A/F gauge is stuck on rich. the car is in limp mode for some reason

 

[pp_puncher]

because it's trying to compensate for the lean condition created by the vac. leak. (that's my guess with the info I have.)

 

[pp_puncher]

What have you done to it recently?

 

[94svtturbo]

i recently pulled the motor and re-sealed everything. so it is a very real possibility that it has a vac leak on the lower manifold. also put in a 255lph edelbrock fuel pump and a bbk regulator. It didnt go into safe mode til today.

 

[pp_puncher]

Yeah the 02's need time to build a fuel trim, so that doesn't suprise me at all. I would say pull the intake manifold and reseal it, also check your plenum gasket. Was it a PI swap ?

 

[94svtturbo]

Yeah the 02's need time to build a fuel trim, so that doesn't suprise me at all. I would say pull the intake manifold and reseal it, also check your plenum gasket. Was it a PI swap ?

IDK what a PI swap is but isnt that for 4.6's? mine is a 5.0

 

[pp_puncher]

right after I posted thAt I realized what I said, I have been drinking, so...LOL I still think you have a vac. leak, You are turbo..do you have a tune and all that good stuff? Have you checked all your couplers especially on the back where you can't see?

 

[94svtturbo]

right after I posted thAt I realized what I said, I have been drinking, so...LOL I still think you have a vac. leak, You are turbo..do you have a tune and all that good stuff? Have you checked all your couplers especially on the back where you can't see?

I have not had it tuned yet. i was just laid off and cant afford it so i just kepp it under 3k and outta boost i drove it like this for like 2 months before pulling th motor out to re-seal it. so it is th same as it was before minus the fuel pump and regulator. i have the complete fuel system just waiting on money and tune to put in my lightning MAF and 42# injectors

 

[pp_puncher]

I'd say reseal the intake with some rtv and let it cure. Thanks for the link!

 

[94svtturbo]

I'd say reseal the intake with some rtv and let it cure. Thanks for the link!

I am going to do that tmrw. i put the motor in this past weekend and have been having idle problems since. it quite annoying actually cuz i miss being able to drive my dream car.

And yeah man. hope to see you over there. we are going to do a few cruises this summer hope you can make them!!

 

[pp_puncher]

You should see my living room, it looks like a chop shop right now (changing rear end to 3.73 00 gt 8.8) and have a new set of wheels, struts and springs to install...I hate the rain

 

[94svtturbo]

haha. for sure. i cant stand the nine months of rain we get. i can see if my we can use my buddy garage to do that in if you want to

 

[MustangChris]

you two are so cute together

 

[kennebellgt]

94svtturbo-
your signature made me laugh my ass off, another thing my car does the same exact thing, same idle problem same hesitation problem, I like hit the gas and its like the motor cuts out than jumps in etc. I hate it, when you find your problem pm me lol, but i think its a vac leak around the area of my iac.

puncher- I love that color of the sn

 

[94svtturbo]

kennebellgt - i was working on it again today and i believe i heard a vacuum leak whistle when i shut the car down. so i replaced the lower intake gaskets and used some black RTV silicone on them. Im waiting for it to set up a little before trying to fire it. I will let you know.


And yeah that sig is pretty entertaining. haha

 

[kennebellgt]

For sure thaks a bunch, I have family that lives on oregon we should cruise if i ever come that way