I have a 1994 Z28 57k original mi.
the only things left that i could possibly bolt on is a cam and new heads.
that being said ive put an edlebrock 7107 intake manifold on it and put 3/8” bead of rtv on the china walls of the lt1. rechecked every fitting vacuum lines ect. on paper theres no vacuum leaks, i recently rebuilt the fuel pump s.o. “Racetronix”, oem fp is rated for 190lph i put a “Walbro 255” in. I have people pointing me in all different directions because it wont idle, and i just replace my throttle position sensor. I know for a fact that its going to need a tune but even with everything that ive done it should still idle right?

 

Does the problem “no idle” = stalls? Or is it an irregular idle, surging, stumbling, etc.?

Auto or manual trans (affects programmed target idle speed vs. coolant temp)? Fully warmed up A4 is 650 RPM in neutral, M6 is 800 RPM.

Have you cleaned the IAC valve? Have you checked the IAC valve resistance?

http://shbox.com/1/iac2.jpg

Have you tried resetting the IAC valve?

4th Gen LT1 F-body Tech Articles

Problem with the IAC valve is there is no feedback to the PCM to tell it whether it is even working, no code.

A list of the mods in addition to the Edelbrock intake, and Walpro 255 would be helpful. Neither of those should affect idle, nor would they make any difference in the idle, or require a tune.

Are you in the US as indicated in your profile? Because you appear to be posting from the Netherlands.

 

Idk what brand the maf is but its an upgrade
k&n cold air intake, bbk tb & long tubes, eldelb intake mani and flow masters, racetronix walbro 255& holley fpr

& you are a legend for helping out

 

[QUOTE=Injuneer;7018510]Does the problem “no idle” = stalls? Or is it an irregular idle, surging, stumbling, etc.?

It wont idle at all when you crack the key it goes to 1k then dies again all within the span of a second

 

Have you cleaned the IAC valve? Have you checked the IAC valve resistance?

http://shbox.com/1/iac2.jpg

Have you tried resetting the IAC valve?

4th Gen LT1 F-body Tech Articles

Problem with the IAC valve is there is no feedback to the PCM to tell it whether it is even working, no code.

I cleaned it already the little plunger, i tried to reset it already

 

m6btw

 

There is no “upgrade” MAF for this engine. Factory part is 100% correct and adequate. And do not delete the inlet side screen. The mods you have made do not mandate a “tune”. The key changes improve air flow into the engine, and the MAF sensor measures that increase.

Aftermarket throttle bodies can cause trouble with idle, but not complete idle failure. The other mods are not very useful for a basically stock engine. Stick with stock 48mm throttle body until you get into heads/cam. Edelbrock intake reduces plenum volume, and can affect HP on highly modified engines. Stock fuel pump is fine for stockish engine. Stock (non-adjustable) FPR is very reliable.

I bought into all the “mods” when I bought my 94 new. They were basically useless. Only significant improvements were CAI and upgraded exhaust. Even when the engine was cranking out almost 500 flywheel HP the shop that built the engine laughed at my 58mm throttle body, showed me on the engine dyno that it made max HP at only 75% open. Guy that bought my Formula couple years ago is probably making an additional 50 HP, has gone to a single plane intake manifold, huge fabricated sheet metal aluminum intake manifold (more plenum volume), but is using a stock throttle body. Not sure what he did with my 58mm Holley.

Were you careful not to get solvent into the IAC motor/electronics? Did you avoid moving the pintle manually?

Have you checked fuel pressure?

Is the “SECURITY” light staying on?

 

Were you careful not to get solvent into the IAC motor/electronics? Did you avoid moving the pintle manually?

Have you checked fuel pressure?

Is the “SECURITY” light staying on?[/QUOTE]

Fuel pressure is better than ever i redid the entire intake manifold just to see if i was lacking RTV (i was) fixed that, every vacuum line looked pristine, cleaned the iac valve and still doesn’t idle a buddy of mine told me to put gas in it but i poured 5gal in it when i first started it, at one point i got it to “somewhat” idle but it would climb to 5k and start redlining without pushing the pedal sounded like it was about to blow up or something but now i cant get it to idle at all. when it was idling like that i took it for a drive around the block and everything seemed to be fine

And all the mods came with it when i bought it lol i havent thrown any money into it yet lol