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BossRoss45
10-06-2014, 06:07 PM
I need some serious help. I just had a 75mm Throttle Body, 3" Fresh Air Intake system, Idle Air Control Valve and a Throttle Position Sensor installed on my baby (94 SC, 5speed). I just got the car back and I know that it is not running correct. It is idling way too high and when I drive it..it seem to have loss some of its power/push. When the car is sitting still and you push and then let off the accelerator it will idle around 2000 rpm for about a minute or two before it begins to idle down. When you are driving you can hear the engine racing. When you change gears and hit the accelerator it don't push like it did. No force at all. It's just not running like I want her to. I like the intake system, I just want the extra force and her to idle correctly.

Would someone please help me? I tried adjusting the Idle Speed Valve, but it is at its lowest point.

I don't want to mess my baby up so I wanted to ask the Experts here for some step by step advise on what needs to be done to get her idle correct and her power returned.

62093

elanoresc
10-06-2014, 08:32 PM
Start with what you did listen for iac to be hissing also make sure t/b is sealed up I would lean the way of both

BossRoss45
10-07-2014, 12:05 AM
Start with what you did listen for iac to be hissing also make sure t/b is sealed up I would lean the way of both

thanks for the response. I actually don't hear any hissing sounds. I checked everything and every was tight and secure. I really don't want to take it back where it was. Hoping to be able to solve this myself with SCCOA's help.

gr8ghost
10-07-2014, 12:55 AM
Vacuum leaks. Get a tune for it. Also check to make sure the TPS is sealed to the TB. Mine leaked and did the same thing.

DrFishbone
10-07-2014, 07:18 AM
Did you have a new filter and/or MAF installed? If so, it is likely that is what is causing the lack of power - the MAF curve for the new setup doesn't match the MAF of the old.

That looks like a Professional Products TB....as far as the goofy idle...something to check: with car off, remove that idle bypass adjustment screw (near the ports for the IAC valve) and double-check that the hole is drilled completely into the bypass passage. On my Professional Products TB, it wasn't. I think others have had that problem too, but maybe never found out what was up. Without it being drilled all the way, you basically are stuck with the adjustment fully open, which means you are letting a goo deal of air PAST THE IAC VALVE

Next, go thru the TB setup process....basically:


Did you adjust the IAC bypass screw? Its the screw that is on housing that the IAC valve screws onto. You need to screw that all the way in (don't force it) and back it off about half a turn or so. Unplug the IAC and start the car up (you may need someone to feather the throttle to hold the idle at first) then adjust the IAC screw until the car is idling around 500 or so and sounding like its about to die on you. When it can hold its own shut the car down, and plug the IAC back in. You should be good to go for the most part.

Right now its allowing way too much air into the motor hence the reason your seeing that high idle situation. The other screw on the other side is just to setup the throttle stop position. It is not meant to adjust idle.

......

Frit

BossRoss45
10-07-2014, 12:21 PM
Did you have a new filter and/or MAF installed? If so, it is likely that is what is causing the lack of power - the MAF curve for the new setup doesn't match the MAF of the old.

That looks like a Professional Products TB....as far as the goofy idle...something to check: with car off, remove that idle bypass adjustment screw (near the ports for the IAC valve) and double-check that the hole is drilled completely into the bypass passage. On my Professional Products TB, it wasn't. I think others have had that problem too, but maybe never found out what was up. Without it being drilled all the way, you basically are stuck with the adjustment fully open, which means you are letting a goo deal of air PAST THE IAC VALVE

Next, go thru the TB setup process....basically:

Actually, I did have a new air intake installed. Using the old MAF sensor. Yes, it is a Professional Product TB. I am going to remove the whole casing and check for that hole. I hole it is. What size hole did you have drilled for your TB casing?

The MAF sensor? What sensor would you recommend for the is air system?? It's a 3" air in stake with a 75mm Throttle Body.

DrFishbone
10-07-2014, 01:30 PM
Actually, I did have a new air intake installed. Using the old MAF sensor. Yes, it is a Professional Product TB. I am going to remove the whole casing and check for that hole. I hole it is. What size hole did you have drilled for your TB casing?

The MAF sensor? What sensor would you recommend for the is air system?? It's a 3" air in stake with a 75mm Throttle Body.

You may be fine using the stock MAF sensor, however, it is probably a significant restriction (depending on what year your car is). The C&L MAF housings with correct sample tube seems to do pretty well if you don't want to start tuning your car.

Before worrying about the MAF though, check out the throttle body first. I think the car should run fine if the TB issue is resolved. I don't remember what size hole it is...I just grabbed the closet drill bit that fit the existing hole that was started. You don't need to remove anything to check this bypass screw/port. It's on the top of the TB, seen in the picture.

BossRoss45
10-07-2014, 02:08 PM
You may be fine using the stock MAF sensor, however, it is probably a significant restriction (depending on what year your car is). The C&L MAF housings with correct sample tube seems to do pretty well if you don't want to start tuning your car.

Before worrying about the MAF though, check out the throttle body first. I think the car should run fine if the TB issue is resolved. I don't remember what size hole it is...I just grabbed the closet drill bit that fit the existing hole that was started. You don't need to remove anything to check this bypass screw/port. It's on the top of the TB, seen in the picture.


Thanks. By the way, it's a 1994 SC

SCarSC
10-07-2014, 02:43 PM
since im not looking at my car right now it might just not be very obvious...but is the tps plugged in?

BossRoss45
10-07-2014, 09:25 PM
since im not looking at my car right now it might just not be very obvious...but is the tps plugged in?


Everything regarding the TB is fine. I found an issue. There was a plastic ring on the old TPS that I did not remove and put on the new TPS. This was allowing air into the TB. I put the ring on the new TPS and the idling came down to normal.

However, now I just need to check on why when I hit the accelerator the rpms don't drop right away as they use to. They stay up around 1500 for about 2 to 5 seconds then drop to normal. Then happens even when I am shifting through the gears. Sometimes it almost feels like the car is pulling itself. I know it's not the case. Just feels that way. Its not bad, but rather have it a little more fine tuned. I checked for any other leaks and just can't seem to find anymore leaks. I am sure it is something real simple that need to be adjusted. Will keep playing around and I am sure it will adjust.

Anyways, I want to say thank you to all for the advise. I did everything that was recommended and it solved the high idling issue. My baby is almost back to herself with a little more power to use. I still think she is lacking a little in power since the installation, but will see after the rpm issue is resolved.

Again, thank you to everyone. This club is awesome.

DrFishbone
10-07-2014, 10:03 PM
Whoa - auto huh?

Make sure the TV cable is adjusted appropriately! Not sure if it's as critical with the late autos, but with the AOD (early SC's) maladjustment of the TV cable can lead to a quick transmission failure!!!

Do a search for the recommended method(s)!!

elanoresc
10-07-2014, 10:16 PM
Matt if you look in the pic he don't even have one hooked up I just figured aode had electronic shift and not old school cable but I did not know.

DrFishbone
10-07-2014, 10:56 PM
Matt if you look in the pic he don't even have one hooked up I just figured aode had electronic shift and not old school cable but I did not know.

I'm dumb. :o

Nevermind then....lol.

BossRoss45
10-07-2014, 11:33 PM
I'm dumb. :o

Nevermind then....lol.


I'm sorry. I guess I should indicate the vehicle being worked on. 1994 SC 5speed.

DrFishbone
10-08-2014, 07:29 AM
I'm sorry. I guess I should indicate the vehicle being worked on. 1994 SC 5speed.

Lol - stop!!! You're making it worse!!

:o

CaifanSC
10-13-2014, 11:54 AM
Still sounds like an IAC valve...since it was removed, maybe the gasket was not placed correctly? I'd remove it to check it out and give it a clean. It's easy enough with everything else still in the car.

BossRoss45
10-13-2014, 12:30 PM
Still sounds like an IAC valve...since it was removed, maybe the gasket was not placed correctly? I'd remove it to check it out and give it a clean. It's easy enough with everything else still in the car.


I took the car to Ford (waste) and had them check it out. They did some adjustments and set the TP to the correct settings. Said there were no vacuum leaks. Ford said 1)when starting the car it will idle around 1500 for a few seconds and then drop (this is normal for an after market TB); 2) when driving the car the rpms are supposed to stay high when shifting through gears, even if the car is in neutral (this is normal for an after market TB); 3) this is normal operation when an aftermarket TB is installed on car. I told him I can move this car without pushing the accelerator. This car drives itself as if it was an automatic. Shifting....I don't have to push the accelerator when shifting because the RPMs provides enough power to move the car.

I am good for now. I don't want to continue beating a dead horse issue. I will probably contact the SC TECH (he was recommended in one of the Forum discussions as a knowledgeable SC mechanic) located in Bedford, Texas. It's an old Post dated 2013 so I hope he is still available. If you know of any SC Experts in the Dallas area (East Dallas preferred) that would be great.

Falcon20x
10-27-2014, 03:47 PM
if you are sure it is not a vacuum leak try this.

Take the intake tube off and check the position of the butterfly valve. The idle screw can vibrate lose and do the same thing you are talking about.

BossRoss45
10-27-2014, 04:04 PM
Received a lot of support to fix this issue. Some of which I have not tried yet, however, I will. I just want to say thank you to everyone and all your expert advise.