Speed Density Guys- NEED HELP PLEASE

Rick 91GT · 06-18-2001, 09:59 AM

Well I am SD stupid since I am a mass Air guy. My buddy's 88 has a horrible surge to it, I though it was the IAB but after the install of a brand new sensor it still does. Then I though maybe it is the "BAP" or "MAP" what ever that is on a SD car, I disconnected it while it was running and nothing happened, I though that a SD car relied on that sensor for it's functions. He replaced that as well but it still does it? Could it be a sticking or dirty injector, the car sat for 3-4 years but it has been running great for the last 3 days since he got tags on it, we have had it running for over 3 months now and have never seen this problem, but it has only really been driven these last couple of days. Any ideas would be apprecaited, he has a A-trim on the way and I need to get thios fixed before I install the blower.

Thanks Guys!

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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

joe4speed · 06-18-2001, 11:59 AM

If it's been sitting for so long, did he clean the IAB? My '88 did that for years, and especially when I disconnected the battery for something. After I drove around for about 40 miles it would stop until I disconnected the battery for something again. As soon as I switched to Mass Air, the car never did it again. Good luck!

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Joe! 1988 GT, 167,000 miles!!! 13.58@105mph Check out my listing! Click here! Or my website:www.joe4speed.com
99 Ninja ZX-6R:10.32@135mph!
1993 Olds Eighty Eight LSS 16.40@88.8mph

QUIN · 06-18-2001, 12:35 PM

hey rick, did you try changing the TPS? mine was doing that about 2 years ago and i swapped tps, set it, and it cleaned it right up.
i assume you thought of that, but maybe you overlooked it,,,,,
just a thought.
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!

QUIN · 06-18-2001, 12:37 PM

although we could very easily be fighting the same problem!!! which i would love to figure out!!!!!
Q

Rick 91GT · 06-18-2001, 01:01 PM

Quote:

Originally posted by QUIN:
hey rick, did you try changing the TPS? mine was doing that about 2 years ago and i swapped tps, set it, and it cleaned it right up.
i assume you thought of that, but maybe you overlooked it,,,,,
just a thought.
Q

I thought about the TPS but since the IAB was bad I didn't want to change the TPS setting, now he got a new one today so tonight if he can get off I am going to check the tps and go through everything to see if I can get it to work.

------------------
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 · 06-18-2001, 01:29 PM

hey man, 'when' (not if) you figure it out, please let me know so i can check the same thing on mine! sounds like we are in very similar situations here. if i figure it out i will do the same for you of course.
may the force be with us,
Q

exgmguy · 06-18-2001, 06:07 PM

Blower? Speed density?

Uh oh....

Unit 5302 · 06-18-2001, 07:57 PM

Unless you have an A trim for a SD car, you'll have to convert to MAF.

Maybe. If you had an FMU you might be able to get away with it, lol.

As a general rule, without proper tuning SD doesn't like big changes.

If you disconnected the BAP sensor while the car was running and nothing happened, that's your problem. You either have a rotted out vacuum line going to it, or the BAP is bad. If you disconnect that thing it should lope, burp, load up, and run like it's got a .600lift cam in it. I should know, I've done it just for laughs once. At idle just for a minute

. Anyway, my vacuum line was bad going to it, and it really caused some problems. That's where I'd look.

Rick 91GT · 06-19-2001, 07:24 AM

Yes a A-trim for a SD car, according to Vortech and a couple tuners it can be done as long as it has the blow off valve and the air is released into the atmosphere, and it has the FMU. He plans on going to Mass Air later this year, or sooner if Vortech is wrong. The Accel DFI is a Speed Density system adn lots of people run these with blowers, however I do understand that a DFI is tunable.

PROBLEM SOLVED!
Well we fixed the problem, it was the top vacuum module that is located on the passenger side shock tower. Thanks for all the advice and help.

------------------
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

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06-18-2001, 09:59 AM	#1
Rick 91GT Procharged! Join Date: May 1999 Location: Hanover, PA Posts: 1,539	Speed Density Guys- NEED HELP PLEASE Well I am SD stupid since I am a mass Air guy. My buddy's 88 has a horrible surge to it, I though it was the IAB but after the install of a brand new sensor it still does. Then I though maybe it is the "BAP" or "MAP" what ever that is on a SD car, I disconnected it while it was running and nothing happened, I though that a SD car relied on that sensor for it's functions. He replaced that as well but it still does it? Could it be a sticking or dirty injector, the car sat for 3-4 years but it has been running great for the last 3 days since he got tags on it, we have had it running for over 3 months now and have never seen this problem, but it has only really been driven these last couple of days. Any ideas would be apprecaited, he has a A-trim on the way and I need to get thios fixed before I install the blower. Thanks Guys! ------------------ 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

06-18-2001, 11:59 AM	#2
joe4speed He said Member...heh, heh Join Date: Sep 1999 Location: Jupiter, Florida U.S.A. Posts: 3,718	If it's been sitting for so long, did he clean the IAB? My '88 did that for years, and especially when I disconnected the battery for something. After I drove around for about 40 miles it would stop until I disconnected the battery for something again. As soon as I switched to Mass Air, the car never did it again. Good luck! ------------------ Joe! 1988 GT, 167,000 miles!!! 13.58@105mph Check out my listing! Click here! Or my website:www.joe4speed.com 99 Ninja ZX-6R:10.32@135mph! 1993 Olds Eighty Eight LSS 16.40@88.8mph

06-18-2001, 12:35 PM	#3
QUIN Registered Member Join Date: May 1999 Location: Chillicothe, OH. Posts: 1,289	hey rick, did you try changing the TPS? mine was doing that about 2 years ago and i swapped tps, set it, and it cleaned it right up. i assume you thought of that, but maybe you overlooked it,,,,, just a thought. Q ------------------ 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!

06-18-2001, 12:37 PM	#4
QUIN Registered Member Join Date: May 1999 Location: Chillicothe, OH. Posts: 1,289	although we could very easily be fighting the same problem!!! which i would love to figure out!!!!! Q

06-18-2001, 01:29 PM	#6
QUIN Registered Member Join Date: May 1999 Location: Chillicothe, OH. Posts: 1,289	hey man, 'when' (not if) you figure it out, please let me know so i can check the same thing on mine! sounds like we are in very similar situations here. if i figure it out i will do the same for you of course. may the force be with us, Q

06-18-2001, 06:07 PM	#7
exgmguy Registered Member Join Date: Feb 1999 Location: Utica, Michigan Posts: 2,631	Blower? Speed density? Uh oh....

06-18-2001, 07:57 PM	#8
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	Unless you have an A trim for a SD car, you'll have to convert to MAF. Maybe. If you had an FMU you might be able to get away with it, lol. As a general rule, without proper tuning SD doesn't like big changes. If you disconnected the BAP sensor while the car was running and nothing happened, that's your problem. You either have a rotted out vacuum line going to it, or the BAP is bad. If you disconnect that thing it should lope, burp, load up, and run like it's got a .600lift cam in it. I should know, I've done it just for laughs once. At idle just for a minute . Anyway, my vacuum line was bad going to it, and it really caused some problems. That's where I'd look.

06-19-2001, 07:24 AM	#9
Rick 91GT Procharged! Join Date: May 1999 Location: Hanover, PA Posts: 1,539	Yes a A-trim for a SD car, according to Vortech and a couple tuners it can be done as long as it has the blow off valve and the air is released into the atmosphere, and it has the FMU. He plans on going to Mass Air later this year, or sooner if Vortech is wrong. The Accel DFI is a Speed Density system adn lots of people run these with blowers, however I do understand that a DFI is tunable. *PROBLEM SOLVED!* Well we fixed the problem, it was the top vacuum module that is located on the passenger side shock tower. Thanks for all the advice and help. ------------------ 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