02 GT won't start after CAI/TB/plenum install

zenboy99

Founding Member
May 12, 2002
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Madison, WI
This is my first time working on a modular car, but I've done alot with EFI pushrod motors.

I installed the following on my mom's 2002 5 speed GT
-JLT cold air intake
-Professional products throttle body
-Professional products intake plenum

Car was running fine before install, idle may have been a tiny bit rough. Only 46,000 miles on the car and no codes.

After installing all of these the car doesn't start, it fires up then imediately dies. I've played with the idle set screw, checked to make sure everythings plugged in, reset the EEC, etc. Car still won't hold an idle.

Any help would be greatly appreciated.

Thanks,
 
jeffnoel said:
Idle set screw??? The compuiter handles that so I don't know what the screw your turning is doing.

Your Mom's gonna be so pissed you broke her car. :nonono:


Shouldn't have an idle set screw.

However it does have a TPS (throttle positioning sensor) which is VERY touchy. Did the new throttle body come with its own TPS? If not, you will have to get a volt-meter and make sure the voltage of the stock one is still in spec. Spec should be .98Volts (or .97 or .99 volts, as long as it is UNDER 1 volt)
 
Just make sure there is no leaks and everything is plugged in correctly. Disconnect battery for a couple hours. Reconnect the battery, after starting let it idle to full normal operating temps with touching the gas. There can be no leaks after the maf. If you can make it idle by applying the gas maybe it's something to do with the idle control valve.
 
Just as everyone said, check all the connections agan quick. There really is not that many, I just installed a t.b. and plenum on my car tonight and had no problems, fired right up. As mentioned, you said you played with ur idle screw, as mentioned, there isnt one, so it seems you might have messed with something that didnt need messed with....hopefully you can fig. it out and get it running
 
BurningRubber said:
Off topic with the subject, but how is the PP tb and plenum? Put together and finished nice? Im set on going that route and want to see if they have nice products.
I put mine on a few weeks ago. Quite nice looking actually. I ende up having to drill the throttle cable holder hole to an even 1/4" cuz it was too small so check if that silver fitting on the end of the cable fits first. I can take some pics sometime and post.
 
BlownStangGT said:
Just as everyone said, check all the connections agan quick. There really is not that many, I just installed a t.b. and plenum on my car tonight and had no problems, fired right up. As mentioned, you said you played with ur idle screw, as mentioned, there isnt one, so it seems you might have messed with something that didnt need messed with....hopefully you can fig. it out and get it running

The idle set screw is the screw that adjusts the stop of the throttle plate. The instructions said it should be set correctly from the factory but it seemed much more shut then the stock throttle body. Thats why I tried opening it up a little bit.

Rechecked everything last night and reset the EEC, still no start. I'm going to hook my Tweecer up to it tonight, if I don't see anything I guess I'll just start to put the stock stuff on one piece at a time and see if starts.
 
CobraRed_96_GT said:
I put mine on a few weeks ago. Quite nice looking actually. I ende up having to drill the throttle cable holder hole to an even 1/4" cuz it was too small so check if that silver fitting on the end of the cable fits first. I can take some pics sometime and post.

I had the same problem. Thats the deal with Professional Products, their whole company is buying old/bad casts from companies, so there's always something wrong with their parts. Typhoon intake (Edelbrock clone) has an ovalized water neck, their 94-95 throttle body has to be redrilled to install on the car, etc, etc.

I really like the tb and plenum, they look real nice. The JLT cold air intake is junk, they didn't send me 2 of the clamps that I need, the rubber fittings are way too small to get over the pipe (even the company admits it) and the whole unit just doesn't seem stable. I had to go out and buy 2 clamps and a rubber grommit to get the thing to fit securely.
 
zenboy99 said:
I had the same problem. Thats the deal with Professional Products, their whole company is buying old/bad casts from companies, so there's always something wrong with their parts. Typhoon intake (Edelbrock clone) has an ovalized water neck, their 94-95 throttle body has to be redrilled to install on the car, etc, etc.

I really like the tb and plenum, they look real nice. The JLT cold air intake is junk, they didn't send me 2 of the clamps that I need, the rubber fittings are way too small to get over the pipe (even the company admits it) and the whole unit just doesn't seem stable. I had to go out and buy 2 clamps and a rubber grommit to get the thing to fit securely.

Sorry to hear about your problems. I also install a plenum/tb combo with no problems. I also have the JTL ram air kit. My painted intake tube cracked and they replaced it no questions asked. JTL will work with you to make things right. Good luck Pearl.
 
Good luck....off topic a little but anyone looking for a plenum/t.b. combo I will pass you onto the rpm/c&l plenum and bbk throttle body for $249.95 from rpmoutlet. It says its 279, but when you click on the link it comes up at 249.95, i ordered one right away!
 
BlownStangGT said:
Good luck....off topic a little but anyone looking for a plenum/t.b. combo I will pass you onto the rpm/c&l plenum and bbk throttle body for $249.95 from rpmoutlet. It says its 279, but when you click on the link it comes up at 249.95, i ordered one right away!


!!! oh hells yeah....:SNSign:

40 bucks more for proven products...
 
Its always something simple.....

Pulled everything off and realized that I put the MAF on backwards! So the air flow was going in the wrong direction, couldn't get an accurate reading and wouldn't idle.

Felt hardly any horsepower difference, pulls a tad bit harder up top, but there's no way my mom's going to notice anything.

With that in mind, what would you guys suggest for the next mod? I have no clue how these cars respond to mods.
 
zenboy99 said:
Its always something simple.....

Pulled everything off and realized that I put the MAF on backwards! So the air flow was going in the wrong direction, couldn't get an accurate reading and wouldn't idle.

Felt hardly any horsepower difference, pulls a tad bit harder up top, but there's no way my mom's going to notice anything.

With that in mind, what would you guys suggest for the next mod? I have no clue how these cars respond to mods.


Well... what good is more air coming in, if you arent moving more air out?

Do some exhaust work next... if she doesnt want it loud you should do a catted H or X pipe, and maybe some weld in Dynomax Super Turbo's or something. If she doesnt mind some noise, but nothing insane id do an offroad H or X and the stock catback.
 
BurningRubber said:
Well... what good is more air coming in, if you arent moving more air out?

Do some exhaust work next... if she doesnt want it loud you should do a catted H or X pipe, and maybe some weld in Dynomax Super Turbo's or something. If she doesnt mind some noise, but nothing insane id do an offroad H or X and the stock catback.

Looking at those OHC heads, headers look like a nightmare to install, so maybe I'll stay away from that. A catback would be a nice mod, she wanted a little rumble, but not too loud. I know on my 5 Liter, a catback did nothing, the stock catback was pretty efficient as is for bolt-ons, is that the same for this car? If so maybe I'll go with a catted x or h pipe.