Idle questions

[DarkknightGT]

Hello again everyone! Update on my last vacuum post:

I found another leak and plugged it (open port on the charcoal canister, fuel smell is gone. Yippee!)

Whenever the car cold starts the idle is OK, Meaning the idle needle skips slightly, doesnt surge all that much but its very puzzling. After letting it run like that for a minute I shut it off, then turn it back on. Its like the car rolled off the assembly line again!! The idle is smooth at 850, throttle response is instant and idles down quickly, life is good! Fuel pump is newish (only a year old with little run time, had to put a transmission in), spark plugs look good but have a tiny film of oil on them, it has a CAI with a new filter. Plug wires, distributor, ccrm, and ignition coil are new ish with very little run time. I'm at a loss with this. Do I live with it or is there a fix for this? Help!!

 

[RAU03MACH]

if you know how to do a compression test
i would recommend it
a slight oil film on plugs would have me freaking out
it would let you know if rings are bad or head gasket leaks
just take note on cylinders comp. numbers

 

[DarkknightGT]

if you know how to do a compression test
i would recommend it
a slight oil film on plugs would have me freaking out
it would let you know if rings are bad or head gasket leaks
just take note on cylinders comp. numbers

Correct me if I'm wrong but wouldn't blue smoke show up if it is piston rings? I dont have any smoke coming from the engine or anything. Idk if the pcv valve was changed when my dad did the intake as well. I also get no bubbles and this engine hasn't overheated at all. It runs great other than that issue. Not knocking the compression test though, I wanna do one of those just to see.

 

[RAU03MACH]

blue smoke is oil

 

[DarkknightGT]

blue smoke is oil

No blue smoke at all. Its predominantly on the threads and a little on the tip, but nothing major. Could it also be the pcv valve? I'm suspecting that tbh as well.

 

[ttocs]

do you have any sensors that used to have two clips on either side to hold it but now only has one? I learned a rough lesson after one of the mounting tabs broke off the tps, but I figured it was good enough with one so I ran it. It was fine starting up but once the motor got hot it would start to drift slowly till it would show %5 throttle when it was idling.

 

[DarkknightGT]

do you have any sensors that used to have two clips on either side to hold it but now only has one? I learned a rough lesson after one of the mounting tabs broke off the tps, but I figured it was good enough with one so I ran it. It was fine starting up but once the motor got hot it would start to drift slowly till it would show %5 throttle when it was idling.

Checked all my sensors and cleaned them. Nothing out of the ordinary. However, my purge valve doesnt have a line going to the charcoal canister at all. Could that cause it to behave a bit erratic at cold start but be fine once it warmed up?

 

[Fawls]

Valve stem seals? Common issue with these (old) engines.

 

[DarkknightGT]

Valve stem seals? Common issue with these (old) engines.

Took it out again. REEKS OF FUEL. So I suppose it may not be oil. I misinterpreted it and said oil (god I'm an idiot) I will do valve stem seals tbh. This motor will come out and its getting all new gaskets and seals tbh

 

[96blak54]

I just wrote this up on a different post and it fits here too

We modular nuts are discovering the original plastic intake manifolds degrade with age, including the original intake manifold gaskets which in turn will allow a hidden vacuum leak. With this said if you have updated to a better original Ford intake manifold and new intake gaskets, a certain intake manifold gasket is required and not just some run of the mill 4.6l manifold gaskets. The required 4.6l intake manifold gasket for an original Ford manifold(npi or PI) made by Montaplast requires the thicker intake gaskets made by Fel-pro or Ford(same). These specific gaskets are roughly .040" thicker to compensate for manufacturing warpage of the original 1 piece plastic manifolds. In other words, if you ever have replace intake manifold gaskets with ebay, amazon, or run of the mill 4.6l intake gaskets, you most likely have a leak. How do I know this you may ask?......I worked for the intake manufacture Montaplast and this is well known within the factory. So long story short, hidden vacuum leaks with the original Ford manifolds and original gaskets can have you chasing problems due to age and/or overlooked incorrect replacement parts. Do you know the history of your engine? Has there ever been any manifold work done?

Even the new multi shell replacement manifolds we find are vacuum leaking as well and this may not be the manifold them self, but might be surface preparation. The new manifolds have ring seals around each port. A good cleaned surface is needed to ensure a good seal. Also the npi heads have tiny egr type ports/dimples next to a few intake ports that should be associated with that ports ring seal. Some replacement manifold might not cover these egr ports well

 

[DarkknightGT]

I just wrote this up on a different post and it fits here too

We modular nuts are discovering the original plastic intake manifolds degrade with age, including the original intake manifold gaskets which in turn will allow a hidden vacuum leak. With this said if you have updated to a better original Ford intake manifold and new intake gaskets, a certain intake manifold gasket is required and not just some run of the mill 4.6l manifold gaskets. The required 4.6l intake manifold gasket for an original Ford manifold(npi or PI) made by Montaplast requires the thicker intake gaskets made by Fel-pro or Ford(same). These specific gaskets are roughly .040" thicker to compensate for manufacturing warpage of the original 1 piece plastic manifolds. In other words, if you ever have replace intake manifold gaskets with ebay, amazon, or run of the mill 4.6l intake gaskets, you most likely have a leak. How do I know this you may ask?......I worked for the intake manufacture Montaplast and this is well known within the factory. So long story short, hidden vacuum leaks with the original Ford manifolds and original gaskets can have you chasing problems due to age and/or overlooked incorrect replacement parts. Do you know the history of your engine? Has there ever been any manifold work done?

Even the new multi shell replacement manifolds we find are vacuum leaking as well and this may not be the manifold them self, but might be surface preparation. The new manifolds have ring seals around each port. A good cleaned surface is needed to ensure a good seal. Also the npi heads have tiny egr type ports/dimples next to a few intake ports that should be associated with that ports ring seal. Some replacement manifold might not cover these egr ports well

Upper intake was taken off to repair wiring harness but I can possibly see about replacing those gaskets just in case!