will sct chip help?

[Mustang5L5]

I think with your mods, you do need the 24# injectors, but without a chip, or a proper MAF, I'm not convinced the combo is correctly tuned for them. I've seen cars run "fine" without proper injector calibration, but it might not be ideal. The o2 sensors would inform the computer to just shorten the pulse width way down and you would lower the fuel pressure. Is there an adjustable fuel pressure regulator? If so, I bet it's set under 39psi?

It could be loading up on fuel causing your idle issues.

Run your codes...I'm curious what comes up.

 

[93lxSaleenclone]

No adjustable fuel pressure regulator. Actually my fuel pressure guage is pegged out but i havent got to check it out yet. It was that way when i got it. I pull codes tomorrow and post back

 

[vristang]

You have a fuel psi gauge, but not an AFPR?

Pull your codes, as already suggested...

I'd be willing to bet money that if you were to put 19 lb injectors in the car it would idle and run perfectly.

Not with a 93 Cobra MAF it wouldn't...

Get a MAF housing that's calibrated for 24 pound injectors and put your Cobra sensor into it. I bet that fixes it too.

Not with an A9*/A3M series computer...

Either combination might get the car to run, but it wouldn't be right... you would be relying on the Adaptive Strategy to get the car running decent.

 

[stanger9410]

Other than at idle do you feel it ran worse than before you installed the chip?

it ran better after the chip, it idled correctly and i wasnt losing power on the top end. it was a good use of $300

 

[93lxSaleenclone]

I tested the wires to the IAC with my meter and got 14.49 to engine ground and 13.44 to return wire/computer ground. So I assume thats working properly?

Pulled codes and got these.
engine off codes:
33

engine on codes:
21
94
44
33

I still get no change in idle when I remove the plug to the IAC. Although it idles perfectly when I started it to warm it up to do the tests.

 

[Mustang5L5]

Well, the idle should change really. At idle, the ac should be closed, or pretty close to it.

When you pull the plug out, if the ac if full closed, nothing should change.

When you ran the engine codes, did the engine idle up?

Try this. Get the engine warm and toasty and unplug the iac. Now, back out the engine throttle stop screw and back the idle down. Get it to the point where the engine is about to stall. Then shut it off, plug the iac back in and reset the computer by unplugging it for 15 mins. That should reset idle.

Now, the lack of iac codes suggests the idle screw is set too far in keeping the iac closed most of the time. Back it down and see if that changes anything.

Honestly, I think the iac issue is a bandaid for the injector mismatch. Im assuming a lot here but i bet The idle was probably poor, so the idle screw was opened a bit to keep a steady idle forcing the iac to remain closed to try and lower the idle. You might have idle issues as you lower the idle down.

Typically if the iac is not working right, you get two codes.

Edit: ok, there is a few, but the one I was specifically looking for was 36/37 which is the computers inability to raise idle during the koer sequence. The lack of that code suggests the iac was able to raise the idle during the test.

Again, I'm not there so I'm taking an educated guess

 

[93lxSaleenclone]

Yes the idle raised during the test. When I set the idle again a few days ago I did it with the iac unplugged to begin with. I set it around 800 where it seems like a good idle (sound wise) then plugged the IAC back in, reset computer and thats where I am at now. When I start the car cold it idles around 1400 for about 15 seconds then drops back to around 850 and stays there. When warm I sometimes get the surge for about 15 seconds then drops back to 850 and stays there. It is still running great. Excellent throttle response with no hesitation what so ever.

 

[Mustang5L5]

So it raises idle during the test and no iac codes?

Iac is fine.

 

[93lxSaleenclone]

Im going to take a couple videos of my idle tomorrow and post them. Maybe i'm just looking at it too much. Its not actually causing any driveability issues.

 

[2002BLGT]

With the Cobra MAF and 24lbs injectors , the easiest and fastest 2 ways to fix it would be to locate a X3Z computer which would be expensive or get a chip and use the X3Z.bin file for a startup file and modify it from there , this will get it 95 percent right off the bat .....

 

[2002BLGT]

No adjustable fuel pressure regulator. Actually my fuel pressure guage is pegged out but i havent got to check it out yet. It was that way when i got it. I pull codes tomorrow and post back

If your fuel pressure is pegged high at near 80psi then you have a pinched return line back at the fuel tank , I have seen this a few times when people install new fuel pumps they pinch the line between the tank and the body of the car

 

[93lxSaleenclone]

Ill check the return. In the mean time are any of the codes a cause for concern?

 

[Mustang5L5]

33 is an EGR code. you def want to look at that.

Code 21...was the engine fully warmed up when you ran the KEOR test? If so, this indicates a potential bad ECT.

Run the test with the engine nice and hot. If the code 21 is still in the Engine Running codes, time to check and maybe replace the ECT

 

[93lxSaleenclone]

Anything specific to look at at the egr? The car was probably at about 150 when i checked the codes so it was fully warmed up.

 

[Mustang5L5]

150 is kinda cold. Should be up in the 180-190 range. Does it get hotter than 150?

Code 21 (the ECT) sensor is a sensor you definitely want to make sure is working correctly. It will cause flooding issues and hard starting when it goes bad

 

[93lxSaleenclone]

Yes it gets to 180 to 190. I just didnt let it run that long before hand.

 

[93lxSaleenclone]

Just wanted to post and update...
I got a Moates chip from Willy at dirty dirty racing and it now idles like it should. I'm happy to finally get rid of the annoying surging idle. His customer service was great also.