ok I got a 1987 GTA L-98 350TPI ,700R4 , 3.23 gear's,235/55R16's.with 120,000miles.



MODS Done To It Already;

1. 3" inch exhaust.

2. opend element cone filter.

3. MAF deleted.

E/T By G-tech:

16.23@86.7mph By leaving it in "D" and letting it shift at 5,250rpm

16.11@88.9mhp Manually shifting at 4,750RPM.

Now I'm Not sure how right the g-tech is but That seem's slower then a stock l-98 GTA.
But shifting my self at lower RPM did halp it run a bit faster.
so any help would be good it dsoe need a tune up For sure tho.
Has had one sence 1989.

 

Do you still have a Cat? I'd guess it was plugged if so. I had an 89 vette that went from 16.8 (G-tech) to 13.7 when I gutted the cats.
Just a guess,
Charlie

 

Yea, you have something really going wrong there. L98s should run 14s stock. Look at the cat and do a complete tune-up. How and why did you delete the MAF? If you just threw it in the trash, then thats your problem. Your car needs it, unless you converted to a 730 ECM.
JP

 

Yeah if you just removed the MAF that would be the first thing I;d do in my search for lost performance. Put it back on if thats what you did!!

Also, a clogged cat(s) will DESTROY backpressure and rob a ridiculous amount of power!

Tune up time! If neither of these is you rproblem then it is time to do a full tune up. Many people on these boards when they first get thier thirdgen see some pretty crazy gains from initial major tune ups! My IrocZ went from 14.9s to 14.5s w/ nothing but a freakin' tune up! You could see a gain of like 1 -1.5 seconds easy if stuff has been really neglected!

 

Well the all the mod's listed where do before i bougt it.
The MAF was Deleted by Don Miller Pontiac.
It got faster,was in the 16.30's by G-tech when i frist bought it them mMod's brought it Down to 16.11's.
But I was cjatting with preveiouse owner and said he Never gave it a tune up senc He boght it in 1989.
I knew the Owner Very well he was it buying stupid crap instead of Maintaince I bought the Car in hope's of Saving it from a horrable Death.........
He ran Supertech aka Wal-mart 20W-50 oil,he was running1/2 qt filter .changed it every 8,000 miles.

OIL CHANGES

I ran maxlife 20w-50 and changed it once a week witch was around 400 miles.
for 2 minth's then i filled with amsoil 20w-50 nad i been changing oil filter ever 2,00miles and oil every 4,000.
So Fare it has cleaned out rather Nice oil is still clean when i dump it but i change it away's,every 2,000 and every 4,000.

TUNE UP:

Brass cap and rotor,8mm wire's , and some Ac delco plug's.



Future Mods
52mm TB,swap the 3.23's for 3.73's.
swap the 235/55r16's for 255/55r16's.

then it should be set and ran around town Just how I want it too.
Cause I'm still working on the 91 so i Don't want to waste too much on the 87 GTA.

 

when i got my 91GTA it had 350 TBI, 700R4,3.42's. it had 186,000miles,pluged air Filter.
it Ran 15.69@91.2mph .
after complete Tune up, I swapped in 3.73's right away ,K&N Xtreme Box filter.and knocked out the Cat ran all new 3" exhuast that cheap single pipe in daul tip's. by this time it was at 190,300mile's.

it then Ran 14.86@95.78Mph.


But 200miles after it ran the 14.86 it spun #7 Rod bearing.
So 14.80's ain't bad for an engine about to pop.
But oh Well it's getting a Daul TBI 406 in it now anyway's more
info in the TBI section.

so it really suprised me that the L-98 350TPI only hit 16.11's.
But both car's ran on g-tech pro not sure if there the "Real E/T's"
but it gave me an idea on the gain's anyway.
But i spose lower gear's healthy Tun up and the 91 GTA has the Ramair2 on it so I spose thats why it's Faster.

so even tho there prolly not the right time's (damn G-tech).
but i atleast prooved that the 91 was about 1.2 second's Faster.
I alway's Get told TBI has no performance but in this case it's ouit doing the TPI's Cause i have beaten a few L-98's street racing,some of the LT-1's I could beat on the Ave but we only ran like 0-45mph, an it was only like by a fender and hlaf the door that was ahead of them.But some of them L-98's I could get about 4 ft inbetween my rear bumper and there front bumper, but some modde put one's would hang with me till 70-75mph.
But the 91 was out of steam around 87-90Mph. manually shifting you get it to run strong till about 90-93 then it would fade rather quick by 100Mph it's all done. But i am sure the 406 will run it in to the low 13's to mid 12's i'm told with the power i'm making I should hit mid 11's Launch and Traction pending you know. I'd be happy with 12.40's But we will soon see,Cause when the 91 is done i'll run it at union grove,Heck after i get the 87 Running right and few mod's i'll even run it at the union grove track I'll be sure to post them when i get the time slip's for both.

 

What is the altitude there?

 

Wisconsin mid west Not sure about the Altitude....
Car has been threw heck....


To Learn more about the 91 GTA Ramair2 click link.
https://www.thirdgen.org/techbb2/sho...hreadid=215527

 

I got 2 GTA's.....
but my 91 isn't a TPI so we can't chat about that here.

but we can the 87 GTA.

Well I got a used 87 L-98 GTA Black & Gold I added the Gold for some odd reasin.
But car look awsome till it got slammed into
Car was out front and Drunk slammed into it....

Dude hit it and backefd up and ran they cautgh him But he was uninsured.

I Didn't have much cash so i got a firebird hood and fender's and front bumper i had laying around,and well a buddy oi mine jas an awsome Black&sliver 86 FireBird with a 327 in it.
so we decided to Clone it with my poor GTA so i put on the Firebird Front Clip.
painfully yanking them shiney Gold GFX off I got one tail light lance swapped and wiring done But not the other side so it look's goofy as heck well then it hit me Oh My i'll have get rid of them shnazzy 16's.
B ut then my Buddy Brant was like hell don't do that Clone my body use your wheel's and Color sceme. I was like hell yes........
But 2 of my rim's where beat up on the GTA ,but i found a set of l;ook alike 15x7's so what i Did is put 2 of the 15's on the front and 2-16's on the rear ,
it looked so sweet i did it to my 91 GTA as well.
so in the end it came oput all good .......
Hopfully by summer the GTA/Firebird will be ready to go looking awsxome But Every one is now going to look at it as just a "FireBird",only thing that will erk me.
But i'm thinking it will be more fun smoking sombody with a car that say's firebird rather then GTA That way they won't see it coming Right???

 

My Main concern is getting the 87 GTA L-98 running 14.60's-14.40's on the street.
It just tick's a guy off when ypu see the LB-9's are running 14.40's 14.20's even 13.80's on the street.
But you Got and L-98 but all you can get is 16.11's....

 

1987 GTA L-98:
https://www.thirdgen.org/techbb2/sho...hreadid=202931 <<scorll down it's there just barried....

1991GTA Ramair2 406TBI:
https://www.thirdgen.org/techbb2/sho...hreadid=215527


Like i say Main Concern is getting 14.40's-14.60's from the 87 GTA L-98 . unless it's going to cost a lot of money then i'll have to go slow for now.

But i do have the 3.73 gear's and 235/55R16's.

I'll Have too wait on these more then likely:

the 52mmTB and eddie intake and runner's will have to wait.

1.it will get the Much needed tuen up tho and the Gear's.
run it and see what it dose with the tune up.

2. then i'll install the gear's,so what it dose with the 235/55R16's.

3. it might struggle with the 3.73's till i get the bigger tires and the 52MM TB, intake and runner's.......
then if i ain;'t in the 14.60's at least I'm just going to give up on performance till the Engine Spin's a Rod bearing Like most 350's do.
and build a 406 for it.
then i'll have a 406-TBI car and 406-TPI a car..
................:hail:...................... :hail:...................... :hail:..................

 

You should be able to run high 13's with the stock L98, 3.23's, good 245/50/16 tires and headers/cat-back. If you have not replaced the plugs/wires/cap and rotor do that first, and make sure your timing is set to 6 to 8 degrees BTDC. Don't waste your money on 3.73's if your going to keep the TPI, same goes for the 52mm throttle body. If you do any intake upgrades replace the base first.

 

You may also want to verify your fuel pressure at WOT under load (like wind it out in 3rd gear) to see if you have a fuel delivery problem before you spend money on any performance parts.

 

put the MAF back on and see what it does. When was the MAF removed?

 

I did forget about that. If they did not re-pin your harness for a 730 ecm and corresponding map sensor then put a known good maf sensor on. You can check and see if they did convert it by looking on the rear passenger side of the plenum for the map sensor.

 

The MAF was Gone when i had boutgh the car...But the I do believe it has the MAP sencor . my TBI had the little retangal Black gizmo on the side of the air filter and there was also and Blue deal the went in the filter too on the TBI it was blue and said AC. when i put the open element i hed get a mounting kit ot mount it to the K&N xtreme box.....
now is this rectangle Black back on my TPI the same as the TBI???cause if thats the map setup then it is there......
Both the Black sencor and the blue secore's are on it.
the Black baoc it sitting mounted up by Firewal wear hood meet's it. the Blus A/C Deal is mounted in the cone filter,along with some other MAF looking Device.


PS:
I wouldn't be wasting money on the 3.73's as i Already have a set.

and when i was going to put on the 52mm TB I had planed doing thre tinake and runner's at the same time,sorry if a confused ya there. "GMGOD".
IF I RUN THE 3.73's on the TPI i'll need the new Base runner's TB 52mm and i'll ptolly up the cam well i got it apart and replace timing chain well i'm at it.

I was Told for racing on the avenue ti run 3.73 gear's and edelbrock base intake the runner's and the 52mmTB.

Base Plate:
http://store.summitracing.com/produc...earchtype=ecat

52mmTB:
129-1534 TPI 85-88, Twin 52mm www.jegs.com


Runners:
???? edelbrock had them now i can't find them??

 

Now I did Get a MAF a new one $215.00 Then I went and got all the Ducting and the Air Box,For Another GTA in the Junk yard....
Installed them Pluged it in got and ses light and it ran for ****...
ulled + vcable off for an Hour.
Started car back up Light Went out . seem ed to Run Ok Idled Rought now tho.
reG-teched it and it Ran a tun's in the 16.30's it slowed down.
Then after second Run it threw SES light.
scanned it Bad MAF
pulled the New MAF off re mounted what was there before Pligged Back in the Balck deal in the Cone Filter and Light went out After resetting Computer run Smooth Again re Gteched it back in the 16.11's....
Took the Proper MAF Back to J&H they tested it came Back Good ..... so the Computer isn't ecsepting the OEM MAF...

Now I am What is the deal?? has this car been cobbled beyond fixing??

it Run's Should i just tune it up and leave it be??
in my opinion run this 350 till it die's then drop a nice holley TBI or Carbed , 406SBC in it and call it good like the 91.

 

Do a search for the user name VADER with MAF troubleshooting as the criteria, sounds like one of the maf relays are bad.

 

Vander?? would vander Know what is up with this mess of a car??
Coll thank's Guy good looking out.:hail: :hail:

 

Yea, try the power relay. Its like a $10.00 part. What code is it? If nothing else, it could be the ecm thats bad.

 

If it's the ECM Then i'll take the $3,300 Lose and Junk the damn thing. it's Not worth a $255.69 Part Hell no.
I'll Just Crush it if it's that.........

 

hmmm, i don't know where you get ecms but the last one i bought i paid $20 at the junkyard. If you are going to crush it, give it to me instead, i could use another nice car.
JP

 

I by that stuff Brand new. da Junk yard's around here Refuse to sell that sorta of stuff cause they can test it and there is no return'son the ones that di i ain;'t wasting $20+ on a stupid ECM.
Car Run's fine Run's better with out the MAF it's .3? faster in the 1/4mile with out it but acording to the G-tech it's running 16.11's....

All I wanted to do is get up in the 14.60's-14.40's all i want to do guy's.......
E CM for one is brand new and was tested......
It passed.

My Main deal is I wanted to Modded it up.....
:hail: :hail: :hail: :hail: :hail:

 

If your gonna scrap it, I'll give you a couple bucks for it.

Something is really messed up here.

You had a MAF car, and it was converted to MAP, then you put a MAF sensor on it without properly converting it back?

How did the car run when you tested it, like crap, idled good, felt good the whole way and just no power? What?

 

he never said it was converted to MAP, and just the fact that he plugged the MAF in means the car wasn't converted to MAP, right. I say it is silly to sacrifice a car, or 2 seconds of performance because of $20. I will ship one to you if you want.

 

Don Miller Pontiac.

I will assume (theres that word) that they are not that dumb.

 

I agree but then why would he be able to just plug the MAF back in.

 

Hell, I donno. Doesn't make sense to me either.

For the hell of it, whats the number on your computer?

 

this whole post makes absolutely no sense whatsoever.

That being said - if I was you I'd check into that 91 being legit or not. GTA's never came with TBI. Ever.

And the Maf definitely needs to be on the car. More than likely it is the burn-off relay.

I'm not into prom burning....but is there a way that the dealership could have turned off error code throwing for no MAF?

 

I'm not sure but someone could have easily cut the wire running to the ses light. 91GTA, Do you have a pic of your engine bay?

 

The 91 GTA was L-98 350TPI 3.42's Dude blew it up dropped in a 350TBI close to the same miles and sold it to me for a song....

I ran the 350TBI for a while did a few mod's burned up some tires had fun Blew it up. and it's now in the process of get a dual TBI 406.
Holley commander 950 set up with 2-670cfmTB's.
we clear now on the 91GTA the Ramair2 part before ya go nutso on that is cause it's getting a Ramiair2 Hood.......

there now that the 91 GTA is been exsplained.
Lets go onto thr 87 GTA.

sorry Guy's My bad I figured you would of "assumed "the TBI was a conversion......
But thats all on me My bad.......:hail: :hail: :hail: :hail:

 

it's the 87GTA we are talkin about.
the M A F is gone ......
M A F is not the issue ....
car start's run's like new, no ses Light's. id you put the M A F back on it gives and ses Light but code reader say's error..Flashing Code 999.
But when i leave it off car run's fine.
But it's only running 16.11's according to the g-tech pro.....
I want to get it in the mid to low 14's......

I was listing the MOD's already done....

1. M A F removed.(not the problem )

2. 3" high flow exhaust.(straght pipe with cat).

3.cone filter open element.(reason they had the M-A-F done).

you Guy's went gonzo over the MAF delete.
that is not the issue.....

the issue is i wanna drop 1.5 ta 2 second's off my E/T's if possable

I want to be in the 14.40's with this beast.But i'm starting to lose faith.....

Just Who ever did it didn't remove the M A F plugin just stuffed it back out of the way.....

But at the back of the Plunom there is a funny looking gizmo My 87 Z-28 TPI didn't have..........
on the fire wall above wear the Coil sit's is a little rectangle Sencore or somthing Mounted ALSO there wasn't one on my 87 Z-28.......
My sumption is it was done just wasn't the neatest or cleanest job.....

 

MODIFICATIONS I WOULD LIKE TO DO:

1.complete tune up.(hasn't had one sence 1989)

2. EDELBROCK INTAKE AND RUNNERS.

3.52mm TB.

4.MSD INGNITION UPGRADE.

5.HEADERS.

6.NICE DUAL EXHUAST.

7.3.73 GEARS.

8.B&M FILTER KIT SHIFT IMPROVER.

9.CUSTOM BURNED CHIP.

10.255/55r16'S.

11.CAN SHFAT UPGRADE.(292*DUR.525LIFT).

12. UPGRADE HEAD'S.

13.NICE 10.2-10.6:1 C/R.

Now all of this should wake this old beast up.

 

Stop typing like this, it is hurting my head.

 

sorry guy i didn't mean too

 

Its cool bro.

 

we have yet to prove that, i wouldn't waste money on mods to an ill-functioning engine, it will get you nowwhere, do use all a favor and buy the six dollar burnoff and power relays, the fact that you were able to plug the MAF back in means it hasn't been converted to SD, as far as i know. also do the tune-up and lest us know what happens. this isn't that complicated, there is obviously something hurting your performance, we just have to find it.
JP

 

Alrighty then frewsh tune up and a MAF relay right..
Ok If youe sure I'll Do them first Man........

Thank's for the help.....