I used shbox's test picture
http://shbox.com/1/iac2.jpg
to test my IAC on a 96 Z28. I get a short between both A to B and C to D. Now for the obvious question, is it fried? I realize the picture is for a 95 and not a 96

 

Are you sure your are measuing it correctly (meter set correctly) and at the right terminals?

Why are you testing it might be a good question.

 

Good call shoebox!! Glad you are on Apparently using the prongs from the voltmeter was causing some touching so I used a pigtail to get a good reading(dont ask why I have this pigtail laying around Anyways, the reason I am trying to measure it is because I replaced my ICM about 3 months ago or so to resolve a hard start/cold idle problem. Now it's starting to do the same thing again and I am not sure if my ICM is going bad again or if maybe the IAC was causing issues, readings on the IAC were between 50 and 112 or so which seemed ok. If my ICM is shot I am starting to wonder if my coil might be doing this? the ICM was bought at the dealer and not a "cheap" AZ part

 

Ok so here are the details after a few days...
1) It cranks fine in the morning but stumbles at idle. It accelerates fine. When I pull up to a stoplight when its cold, it idles fine in the first second or so and then slowly it starts idling rougher and rougher.
2) The engine is warm and the idle gets much better but it is hard cranking, usually two tries before it kicks on then has a hard time for a second or two to get to idle. Sometimes if I turn the ignition on and let it sit for about 20 seconds or so before starting it cranks fine.

My suspicions: Fuel, although it has a relatively new fuel pump < 40K and new fuel filter. I have not had a chance to hook up a fuel pressure gauge and watch what happens.

BIG QUESTION:
In my search for answer, I was suspecting the IAC so I pulled the intake elbow and right away I smelled gas, so I opened the butterfly and got a really strong smell of gas coming out of the intake, this was after the car had been sitting in the garage overnight. Could that indicate a leaking injector?

Any help would be greatly!! appreciated!

 

A leaky injector is a possibility. You should also check the temp sensor in the water pump (easily done with a scanner). If it reads continually low, it will make the engine run rich.

 

I did check the water temp sensor and it reads normal (increases with runtime).

Is there an "easy" way to test which injector might be leaking?

 

Not sure what you call easy. You will have to pull up the fuel rail and look at the injectors after pressurizing the system.

 

I will do that soon unfortunately I dont have time this weekend since I need my car. I did however this morning hook up my fuel pressure meter and it showed 0 psi after sitting in the garage after having been parked after 12 hours. Is that normal? or should it hold pressure longer?

 

If you have a leaking injector (or faulty fuel pump check valve or faulty fuel pressure regulator), the fuel pressure will leak down in a matter of minutes, not hours. Prime it, see how high the pressure gets, and see how fast it drops.

 

Thanks Injuneer, I did that test, however I only have one of those "cheap" fuel pressure tester from Harbor Freight and I am just wondering if they are good enough, meaning how can I be sure that the tester isnt leaking the fuel? When I hooked it up, I primed it to 37psi and when I shut it of it slowly went down about 1psi per 10-15 seconds or so. I did not smell any fuel but then it's hard to really get back there. Any recommendations on a better fuel pressure tester or permanent fuel pressure gauge (fuel rail mounted)?

 

Not sure what "cheap" means... a good one only costs $30-35. Does it have the correct -4AN fitting?

A fuel pressure guage is always a good idea, but if you want it in the cockpit, you have to use an electronic guage, and it will cost you $200 before you are done. If you just want it under the hood, a good AutoMeter mechanical guage isn't very expensive, but to install it right you have to buy hardware that costs more than the guage.

If you mean mounting something directly to the rail, as opposed to using the Schrader valve, you have to have to drill the aluminum rail and have an alumimun 1/8" NPT bung welded to the rail. Like this one with the electronic pressure sensor, on my passenger side fuel rail:

http://www.injuneer.com/images/photo...e/DCP04253.jpg

 

That is one sweet setup!! Did you relocate your coil and ICM?

I will stick with getting a better manual one, I would like to have permanently mounted to the fuel rail but I dont really have the time to get all that done at the moment.

 

I don't have an ICM, and I don't run the stock coil..... I run 8 LS1 coils:

http://www.injuneer.com/images/photos/Engine/CoilsL.jpg

Ignition is running off the Opti optical sensor, feeding a MoTeC M48Pro engine management system, with their IEX 8-channel ignition driver.