Casper the Cobra - Procharged 96' Cobra

[Venompower]

The tps should go back to 0 every time the key is cycled. You can’t adjust these like the older ones. Other than a faulty sensor or connector, it shouldn’t be showing that.

Maybe the idle screw has been adjusted too far and the tps will always show that? Have you tried unplugging the IAC with the car running and see what it does? It should idle way down or even die with it unplugged.

Yeah I don't think this one can be adjusted. So that's why I wondered if it's reading correctly but the idle screw was set wrong and so the throttle is open more than it should be?

I will check voltage to the sensor with key on engine off and then check the idle screw.

 

[lwarrior1016]

That’s a very good possibility. They opened the throttle body up to make it run and the tps is reading wrong.

 

[Venompower]

That’s a very good possibility. They opened the throttle body up to make it run and the tps is reading wrong.

I think you are right, seems like way to much screw has been threaded.

The car has a new IAC and gasket, so hopefully this addresses some of my idle issues and then I can plug in the 02’s and check the MAF again.

 

[lwarrior1016]

That does look like a lot of thread there. I would also like to see a jamb but on the back side of the screw.

When you get it up to temp next time, unplug the iac while it’s running and see what it does.

 

[Venompower]

That does look like a lot of thread there. I would also like to see a jamb but on the back side of the screw.

When you get it up to temp next time, unplug the iac while it’s running and see what it does.

I’ve done it before and nothing happened but at the time I assumed it was a vacuum leak... this was probably the issue.

 

[lwarrior1016]

I’ve done it before and nothing happened but at the time I assumed it was a vacuum leak... this was probably the issue.

You’re probably right. I know at a certain point in throttle position, the iac is told to do nothing, it also won’t do anything if it’s already over target idle rpm.

 

[Venompower]

Just got back from going over the car.

So the 02 Connectors would not seat well on the plugs, and are still not registering on live data. Could these be the downstream sensors and would they not fit the upstream connectors? I'll order some new OEM NTK sensors, but would rather not spend $80 bucks if this isn't my problem.

Edit: Got back under it because it was bugging me and the pins in the passenger side are bent and not seating. The driver side upstream seated and upon start the engine immediately smoothed out. I’ll go ahead and order the sensors. Now to figure out how to adjust the rusty screw on the throttle body....

 

[lwarrior1016]

Oh damn, sounds like we are making progress.


Is there a hole in the screw for an Allen wrench to go in the end of it? Like a real set screw has.

 

[Venompower]

Oh damn, sounds like we are making progress.


Is there a hole in the screw for an Allen wrench to go in the end of it? Like a real set screw has.

It’s like a small stud, no Allen wrench hole.

Progress is definitely being made which feels good!

 

[lwarrior1016]

Dang. That doesn’t seem right at all. Maybe two small nuts jammed together on it to make it turn? Hell, put some vice grips on it

 

[Venompower]

Dang. That doesn’t seem right at all. Maybe two small nuts jammed together on it to make it turn? Hell, put some vice grips on it

I was thinking about locking two nuts together like installing a stud.

 

[Venompower]

So went to the junkyard this weekend and managed to find a front passenger side ABS/Wheel Speed Sensor, $10 and I should be back in business with no ABS light. The current sensor wasn't well secured and the wheel rubbed through the wire.

My Amazon special LED fog light bulbs came, I was able to throw one in quickly to test and I think they look pretty good. Need to adjust the fog light and bumper to get better fitment, and need to do the re-pin under the center console so I can run the fogs with just the running lights.

Hopefully the new NTK 02 Sensors will arrive this week, and I can find a way to adjust my idle screw without damaging it.

 

[joemomma]

I adjusted the one on my GT with a pair of needle nose (trying to undo the PO carnage). Hit it with some PB Blaster or WD-40 first and let it soak.

 

[Venompower]

I adjusted the one on my GT with a pair of needle nose (trying to undo the PO carnage). Hit it with some PB Blaster or WD-40 first and let it soak.

I sprayed it with WD40, but I'm thinking some PB Blaster will do the trick.

 

[Venompower]

The PB Blaster did the trick, I turned the idle screw a bit with the intake tube off and the blades appeared close from the start and remain closed... TP (%) signal went from 19.2 down to like 18.6, not sure how much adjustment is left and has me wondering if the sensor is bad? I know you had to adjust the older 79-95 sensors, not sure if the 96-98 are adjustable?

I did get my front NGK 02 Sensors installed first start up was still rough idle, but I'm assuming there is some amount of time for the PCM to register and adjust. Because the second time I started it later in the afternoon the idle was much smoother... Being the scientist I am, in between the two start-ups I replaced the vacuum line between the intake plenum and BOV/Boost gauge connection and deleted the driver PCV out of it, as well as tightened the connection at the throttle body, so it's impossible to isolate what the issue may have been.

I found out the AEM wideband gauge is old enough it uses the Bosch LSU 4.2 sensor, so I'll have to return the 4.9 I had ordered. Can't find any cheaper alternatives that I trust so probably going to have to drop $80 on the real deal Bosch unit, if anyone has used something else that's cheaper with good success please let me know.

Finally struggling to figure out the proper fine tuning of the clutch cable. Getting quite a bit of chatter at the release point. Struggling to figure out how much it should be tightened at the clutch fork vs. fire wall adjustor. Suggestions on that would be appreciated otherwise I'll just take it to the local Mustang shop, because I really want it dead on for good drivability and to not damage the clutch.

Here's a couple pictures including the fog light re-pin:

 

[joemomma]

Man those bumpers look so much better than the GT. I did the fog re-pin on mine, love it.

 

[ttocs]

adjusting the tps is supposed to be for small adjustments, not 18%. Sounds like you can monitor the tps while its live? If so start monitoring it and then go and tap/thump the tps with your fingers/knuckles and see if it drifts. If it does then grab the harness to it and jiggle it and see if it drifts.

 

[joe65]

yeah like the pics of the car.

 

[Venompower]

adjusting the tps is supposed to be for small adjustments, not 18%. Sounds like you can monitor the tps while its live? If so start monitoring it and then go and tap/thump the tps with your fingers/knuckles and see if it drifts. If it does then grab the harness to it and jiggle it and see if it drifts.

Yeah I wasn't even sure if the TPS was adjustable for the 96-98 because I haven't seen any instructions for anything past 95. I'll do some technical taps, and may also check voltage as well if is does drift.

 

[ttocs]

I had this same problem with my tps but it was only showing 5-6% while idling and only when it was hot. I replaced the sensor and it did the exact same thing because it ended up being the harness that was bad.