Still need help with idle. someone please!!!!!

[QUIN]

this is the only thing keeping me from driving my car on a more regular basis. i cant get this idle to smooth out for the life of me.
I used the feeler gauge method and it seemed like it was working. car surged at first and sounded like it was 'searching'. then all of a sudden it found it and held about a 700 idle for 10 seconds or so. i was briefly tickled! all of a sudden it starts surging again, much more violently than before. does this for a minute then just shuts down on the lo-end of the surge. the surge is so low it wont stay running. so then i back it out to see if it will matter to drive it up the road and back,,, no good. still dying w/o foot on gas.
here are my last ideas. replace tps one more time. change my bap to a map (or is it vice versa?) since i never did that when chaging to mass air although the instructions said you didnt have to.
other than this i am running out of ideas.
someone please help!!!! this is killing me! cant readily drive in columbus with your idle pulling this crap!
Q

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Quin, 87 GT,306,forged/cut pistons,edelbrock head\intake,steeda#18cam,1.7rr,MSD Blaster tfi coil,A9L,pro-m75mm,24#inj,accufab65mm,2.5"pipes,hooker headers,dynomax exhaust,3.73 gr,110 lph fp,moroso cold air,ASP pullies, weld rims

See my engine on user rides.

I see your shwartz is as big as mine, now lets see how well you handle it!

[Rick 91GT]

Quin-Did you set the idle with the Idle Air Bypass motor disconnected? If not you should disconnect it when you set the idle, if after you plug it back in and nnothing chages and it still surges, the IAB is bad. You can try to clean it with some WD-40 just do not use Carb Cleaner or it will rot the rubber seal out. Were fighting thios on my bud's 88 right now, although I think his BAP sensor is bad.

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Check Out My Site 91GT,Holley SysteMAX II Kit-Heads 2.02" x 1.60" port matched to a 1262,Anderson N-61,24#,76mm C&L,Full MAC exhaust 1-5/8" Long tubes,2-1/2" O.R H-Pipe,2 1/2" cat back, No A/C or PS or emissions, 12" K&N Filter,RNH PERFORMANCE Ram Air,Ron Davis Radiator,Full Suspension,S&W 8pt "X" brace,JAZ seats,3:73's,Welds..etc,4:30's and 31 splines coming very soon! FIRST TIME OUT 12.16@111 WHEELS-UP

[QUIN]

no, but i set it with the battery out of the car. i figured that was enough. i will try disconnecting the IAB plug tonight and see if it helps. still need to undo the battery i assume?
i fear i have cleaned the IAB years ago with carb cleaner. this could have something to do with my problem then it sounds. how much is an IAB? dealer part?
thanx, it totally sux to have this bad a$$ motor and not be able to drive due to an embarrasing idle!!! plus my stormin norman gets here tomorrow and i want to get all this done!
Q

[Mach 1]

what are the specs. on your cam, specifically the lobe separation angle? If its 110 or less, this could be your problem. I had a similar problem, and after trying EVERYTHING, a cam swap did the trick.

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1993 GT/AOD
'93 Mustang GT

[QUIN]

112lsa which should be perfect. that is one of the reasons i went with this cam. i was having trouble with the idle before i actually did the motor swap too. just not as bad.
im going to get a new map sensor, vaccuum gauge and disconnect the iab as said, perhaps replace it, and try this one more time. any other suggestions would be great. anything that may help. got to discuss a business idea with my buddy tonight out of town, but i will be on this as soon as i return!!! (probably tomorrow when i more than likely call in sick)
thanx !
Q

[302 LX Eric]

Quin - I think Rick has it right. See if that works. If not, (and this is the last alternative I would do), you could always try a custom burnt chip with dyno session. This is definately not the cheapest way to go, but if you have your Stang setup the way you want it and don't plan on making any more serious mods for a while, then this may be the way to go. Plus you will probably pick up some HP and TQ and get a great idle too!

Let us know how it goes.
E

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1991 5.0 LX Coupe - 38,000 miles

13.17 @ 106.14 mph w/ 2.138 60'

[LX XLR8R]

i had a surging idle after my one swap i did and i needed to change out the MAP for a BAP..also what you might want to look into is get rid of the IAB..i made blocking plates for my EGR and IAB sensors and my car idles perfect now..the only thing is that without a IAB the car will run rough for a minute or 2 in the dead of winter..
the main reason i took the IAB out was becasue i didnt like how slow it took the rpms to get down after i reved it..they wanted to stay up and slowely come down..now they come right down to 1000..

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1987 black notch(ex 4 banger)
DSS 306 w/ main support...Elderbrock 6028 heads..gt-40 intake..24# injectors...70 mm tb..77 pro-m...accel 300+..mac full legnth..tremec w/ pro5oh...full MAC exhaust,off road h-pipe,long tubes, catback...ron davis radiator..subframes, control arms...CFDF II..o yea holley FPR sucks..dont buy one..
AIM=onesillynotch

[QUIN]

well, i guess deleting it would be cheaper than replacing it!
i am going to swap to the 89 BAP sensor as well. that may help a bit. have heard similar stories in the past.
i guess ill start with those two things (disconnecting IAB and the BAP sensor replacement) and then if that dont work ill look into sonme of the other possibilities.
i need a dyno anyway,,, so you never know. guess ill just have to see what happens.
thanx!
Q

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Quin, 87 GT,306,forged/cut pistons,edelbrock head\intake,steeda#18cam,1.7rr,MSD Blaster tfi coil,A9L,pro-m75mm,24#inj,accufab65mm,2.5"pipes,hooker headers,dynomax exhaust,3.73 gr,110 lph fp,moroso cold air,ASP pullies, weld rims

See my engine on user rides.

I see your shwartz is as big as mine, now lets see how well you handle it!

[Bronco1]

Did you try cleaning out your throttle body?
You may have some coking. That can suffocate the engine.

[QUIN]

update;
got it pretty much smoothed out now. unhooked the iab and got it to smooth out after resetting it one more time. now, it will surge for about 2 to 3 minutes after start up, then it will smooth out around 1000, 1100 on the stock gauge. i think this is about as close as im going to get it for now.
weird thing is, if i shut it down and restart it, it goes through the whole surging b.s. again for a couple minutes till it smoothes out. i figured once it was warm it would be ready to go even if shut down and restarted.
got my stormin norman last night too and threw it on. looks pretty sharp.
now it appears i am moving back to cincinnati which will put a hold on some projects.
oh well, life is a freken trip.
Q

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Quin, 87 GT,306,forged/cut pistons,edelbrock head\intake,steeda#18cam,1.7rr,MSD Blaster tfi coil,A9L,pro-m75mm,24#inj,accufab65mm,2.5"pipes,hooker headers,dynomax exhaust,3.73 gr,110 lph fp,moroso cold air,ASP pullies, weld rims

See my engine on user rides.

I see your shwartz is as big as mine, now lets see how well you handle it!

[Rich93GT]

Quin,

I had a hunting idle like you describe, and I replaced the TB, the IAB, the TPS and the BAP. When I swapped in a Cobra Intake we found a rotted, torn, scummy vacuum hose under the intake that connects to other vac hoses at the firewall....we replaced that vac hose and now the idle is fine. Good vacuum is very important to these cars.

Good Luck

Rich
My '93 GT Page

[QUIN]

i need to buy a vaccuum gauge so i can check that.
i swear im at the parts store almost daily!!!
usually just for something i forgot the prior day!!!
typical.
thanx,
Q

[Rick 91GT]

Quin- did you see my post on the SD topic I posted. It was the top vacuum module on the passenger side shock tower that was bad, a new one was $30 from Ford and now it idles like a champ, I'll be installing the A-Trim for him in the next weeks. Moving back to Cinn.?

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Check Out My Site 91GT,Holley SysteMAX II Kit-Heads 2.02" x 1.60" port matched to a 1262,Anderson N-61,24#,76mm C&L,Full MAC exhaust 1-5/8" Long tubes,2-1/2" O.R H-Pipe,2 1/2" cat back, No A/C or PS or emissions, 12" K&N Filter,RNH PERFORMANCE Ram Air,Ron Davis Radiator,Full Suspension,S&W 8pt "X" brace,JAZ seats,3:73's,Welds..etc,4:30's and 31 splines coming very soon! FIRST TIME OUT 12.16@111 WHEELS-UP

[QUIN]

yes i am going back to the nati. that didnt last long did it? lol
my ongoing saga with women,,,,,
anyway, im not sure what that vaccuum module is your talking about. i will check your post since i havent yet. if you look back in here, let me know what that is.
thanx,
Q