• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Top Swap having horrible idle, no power on throttle

R

Runicdionysus

New member
Hey guys.
I just finished top swapping my gt this weekend. When I start the car she has a good idle at first and then goes into a horrible idle bouncing between RPMs trying to stay alive. When I unplug the MAF she idles perfectly. So, I went a head and replaced the MAF and the problem persists. What could it be then? I don't understand why it works when I have the MAF unplugged but with the new one plugged in it goes back into the rough idling. Another thing is that when I floor it she barely has any power at all. Any ideas? I'm at a loss.
 


sounds like a vac leak. you get the hvac line on the open port a top the sc yet? if not thats a leak right there.

if thats been hooked up, get some carb cleaner and spray around the engine, if the idle jumps up when sprayed you found your leak area.

spray the sensors too, evap, map, and bbv, the black round thing on the side of the blower with vac lines to it.
 
Scottydoggs said:
sounds like a vac leak. you get the hvac line on the open port a top the sc yet? if not thats a leak right there.

if thats been hooked up, get some carb cleaner and spray around the engine, if the idle jumps up when sprayed you found your leak area.

spray the sensors too, evap, map, and bbv, the black round thing on the side of the blower with vac lines to it.
Click to expand...

Yeah I got that fixed.
Okay, So i used your method and found two vacuum leaks. One of them I fixed, the other one is when I spray the Throttle position sensor. How do I fix that? what does that mean?
 


you have the air filter on there? maybe the spray is getting sucked in the TB opening? or it could be the TB gasket.

did fixing the leak make a difference?
 
Scottydoggs said:
hard say with out being there. next best thing is a vid if you can take one and post it.
Click to expand...

99% sure it's the throttle body gasket. We pulled it off and it's missing a bunch of cut outs the it should have. I ordered it from ZZP and somehow it's nothing like how it should be. Have to make a 30 minute drive to the next town to get a new one because the autozone here doesn't have it in stock. I'll let you know if that fixes the problem!
 
that could do it. make sure both the TB and the sc side are clean and free of old gasket. i little piece left behind and cause a leak.

new razor scrapped over the surfaces goes a long way.
 


Ok, your pcm, who did your file? I'm wondering what maf table you have loaded up on there, unplugging the maf sensor wouldn't fix the vac leaks, it would just make it run off the VE tables instead of the maf table. What year TB are you using? Are you scanning the car? RTV would work for the TB if you haven't left to get the new gasket already, as well.

Picture of the plug you're talking about won't load up, but pretty sure it's for the fp resistor that GT's don't have, ofc the plugs get put on all the cars, later they become GT's or GTP's.
 
99GT2dr said:
Ok, your pcm, who did your file? I'm wondering what maf table you have loaded up on there, unplugging the maf sensor wouldn't fix the vac leaks, it would just make it run off the VE tables instead of the maf table. What year TB are you using? Are you scanning the car? RTV would work for the TB if you haven't left to get the new gasket already, as well.

Picture of the plug you're talking about won't load up, but pretty sure it's for the fp resistor that GT's don't have, ofc the plugs get put on all the cars, later they become GT's or GTP's.
Click to expand...

Reptile tuned my PCM for me. The throttle body is from around the same year as my car. I got it from Morads part company so I don't know exactly. However, it's exactly the same as my old GT TB. I changed the gasket and that didn't fix anything. I'm uploading a video now to YouTube so you guys can see exactly what I'm talking about.
 
99GT2dr said:
Ok, your pcm, who did your file? I'm wondering what maf table you have loaded up on there, unplugging the maf sensor wouldn't fix the vac leaks, it would just make it run off the VE tables instead of the maf table. What year TB are you using? Are you scanning the car? RTV would work for the TB if you haven't left to get the new gasket already, as well.

Picture of the plug you're talking about won't load up, but pretty sure it's for the fp resistor that GT's don't have, ofc the plugs get put on all the cars, later they become GT's or GTP's.
Click to expand...

Also I've been missing work because I can't get anywhere with my car not running. What would happen if I just drove it with the MAF unplugged?
 
You can drive it with the maf unplugged, just stay out of boost. Was looking at the pics you had posted in the other thread, looked like your 02 sensor was unplugged, you got it plugged in right? Could be a bad new maf sensor, where did you get it from? Also, if it doesn't have the big post in the middle, it's a '99+ TB, I suppose reptile could verify what year maf table he used.

So do you have a way of scanning the car?
 


you need to do another vid. when you unplug the maf, you do it car off. then fire it up. same for plugging it back in, do that car off.
 
99GT2dr said:
You can drive it with the maf unplugged, just stay out of boost. Was looking at the pics you had posted in the other thread, looked like your 02 sensor was unplugged, you got it plugged in right? Could be a bad new maf sensor, where did you get it from? Also, if it doesn't have the big post in the middle, it's a '99+ TB, I suppose reptile could verify what year maf table he used.

So do you have a way of scanning the car?
Click to expand...

Yeah the 02 sensor is plugged in. I do have a pretty massive exhaust leak though, because the two bolts from the crossover to the rear manifold broke on me but I don't think that would effect anything as bad as it is right now. And unplugging the MAF wouldn't fix anything that the exhaust leak was causing. My GT is an 2002. So i'm sure Reptile used 2002 tables. I can't really get into boost anyway, the car pretty much has no balls with it unplugged or plugged in.

I used my old MAF sensor from the GT that worked fine before the swap. Then I went to Autozone and brought a brand new one for ~$180 and that didn't fix the problem either.
All i have is a code scanner I don't have any scan tools or anything like that.
 
You must log in or register to reply here.
Back
Top