Heres my problem, I have a 91 rs 305 tbi my engine mods are hyper tech stage II chip, msd 6a box, msd 8.5 wires, accell super coil. flowmaster catback with a catco highflow converter, when the car warms up and drive it for about 30 min then shut it off when i go back to start it whithin the next 30 min or so it starts fine then starts to idle ruff and i have to rev it up some and it sputters then its fine and its worse the nicer it gets. I have changed the map, coolant, and o2 sens. but the problem still happens. my plugs in cylider 7,8 are usually burn't bad. i am considering adjusting the fuel pressure in the tbi but would like suggestions if you have any Thankyou

 

let the car warm up all the way then turn it off. open the hood and see if you injectors have a little drip drip drip when you first cut the engine. if it drips it just means you injectors are worn out. also take a paper towel and wipe the injector tower, if there is any gas on it this will show you if the top o-ring is gone, this is not common but it did happen to me.
the gas will run into the 7 and 8 holes because the back of our engines tilt down hill a little, that would explain the plugs.
does it clear up after you give it some gas or does it stay rough?

hope this helps

lata
tim

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91 Camaro RS-LO3,Auto.
14.301 @ 94.39mph
The car is going street strip for next season. 13's here i come!!!!!
Edlebrock TES Headers, Cat Eliminator Pipe, Borla Adjustable Cat Back,Marche Pulleys, HyperTech Chip,Transgo Shift Kit,B&M Convertor(2000stall),Steve Spohn Rear Rig( all rod ends), Poly Front Bushings,Ported TB, 350 Injectors, Edlebrock Performer TBI Intake, Performer Heads, 1.6 Roller Tipped Rockers
http://www.mycar.net/mafb/registry/detail.cfm?id=299

 

it does it worse when the outside temp it high. i have new injectors in also. when i run the a/c it seems to kill it almost instantly. i was wondering if it could be a bad ecm or faulty wiring after it dies and you restart it the car starts fine then runs bad about 30 sec later

 

Check your fuel pressure.......you may have a bad fuel pump or clogged filter.

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92 Camaro RS LO3, 5-spd, T-tops
Mechanics:
Open Air Element w/K&N Filter, Flowmaster 3" Cat-back Exhaust, Z28 Grille w/aftmkt fog lamps
Electronics:
Alpine 8030 Alarm System, Valentine One Radar Detector (How did I ever drive without one?), Pioneer DEH 7450 Head Unit w/6-pack CD changer, Pioneer DEQ 7600 Sound Processor, 2 Kenwood KAC-90 Amps powering 2 12" Pro Red subs and 4 Infiniti speakers.
NEXT UP: SLP 1 3/4" Headers/Y-pipe, Centerforce Dual Friction Clutch kit

 

I'd have to agree with Pukka, mine had the same problem when my fuel pump was failing. Replaced it, works fine now.

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"The world would have no problems if everyone had a presence of mind."
'91 Firebird
305/TBI(L03)/700R4/T-tops
Mods: Catco high flow cat - B&M Shift kit - TA tail light conversion - K&N - White faced guages on the way
Stereo: Pioneer DEH-P8200R - Pioneer 6x9's - Kenwood 8" Tube
'87 Firebird
LB8/700R4/220K - Twas a good car until the accident.
Firebird parts - Now with an '80 Firebird for sale!
Moderator of Transmission board over at TransAmGTA.com

 

replaced the pump 2 years ago could it have gone out by now?

 

My problem wasn't exactly the fuel pump, but the rubber hose that syphoned gas from the tank. There was a rupture in it as if someone cut it with a knife. Here's the kicker. the more gas got sucked through it, the more the tear expanded due to the heat and pressure. This explained why the car ran fine "cold" but struggled when started up "warm". The only way you are gonna know for sure is to put a gauge or scan tool on it and watch the fuel pressure for drops