I have a 91 Z28 with a 305 TPI. I have a hypertech chip, full exhast, sparkplugs, wires, cap, thermo, K&N, and and air foil. When i am at a sto light i have to put the car in neutral or it will struggle and then turn off. My stater is going because some times it doesnt crank over. Could that be all of my prbblems? If not what so u think it is. I hav been it coudl be the chip, the computer, or a fuel problem. Oh yea, the computer is not spitting out any codes. Thanks for whatever u can do.

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1991 Camaro Z28 305 TPI: Dual K&N Filterchargers, flowmaster 3" cat-back exhaust with 4" chrome tips, Kenny Brown Strut Tower Brace, 17x9.5 Chrome ZR1 style rims, 275/40ZR17 Kumho tires, Eibach Pro-Kit Springs, SLP Headers and Y-Pipe, MSD 8.5mm Super Conductor Wires, Bosch Platnium +4 Spark Plugs, Throttle-Body-Bypass, KYB shocks-struts, Comp Cams Airfoil, HYPERTECH Superchip and 160 degree Thermostat, Rebuilt Tranny with Corvette Gears, Servo, and 2000 RPM stall converter, Custom Super White Sidemarkers, and SYLVANIA Cool Blue Headlights,$2000 Competition Stereo

 

Vacuum leak or low fuel pressure?

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87 Formula 305TPI T5
Cat Back, Underdrive Pulleys, AFPR, Chip, Etc.

 

Mine did the same thing when an injector went bad. I did not see new injectors on your list.

 

Check your base line idle and throttle postion sensor voltage.With the IAC unplugged you should idle at 450rpm (engine needs to be warm)and with IAC plugged in the idle should be around 750 rpm. TPS voltage should be .54 volts (+ or - .075 volts) But your problem could be as simple as a vacuum leak. When I had this problem, my throttle stop screw backed out a full turn causing too low of an idle and a low volt reading on the TPS.The second time, I had a vacuum line come unplugged causing the engine to idle rough and stall.Hope this helps, good luck!

 

where is the vacumm line

 

I had a similar problem too not long ago! I pulled out the IAC and it was filthy. Cleaned the pintle and surroundings with some carbie cleaner. Then I had to readjust idle speed and TPS.

After all that the car does not miss a beat and idles as smooth as hell!

Mike

 

the IAC sensor is in the airbox on my V6 but Where is it in the V8 TPI system. I'm assumin gits somewhere in the induction but where. What and where is the TPS sensor.

 

The IAC on the TPI is below the plenum intake. The TPS is pretty much above it on the same side of the intake. They are both very close together you can't miss them.

 

The IAC motor screws into a port on the bottom of the throttle body. The TPS is on the passenger side of the throttle body controlled by the shaft that opens the throttle plates. IAC has a 4 conductor plug for forward and reversr (pintel in/out) The TPS has a 3 conductor plug. Connect voltmeter + to center wire, - to chassis ground to check for .54 volts. On most TPI units, loosen 2 screws on TPS sensor and rotate CW or CCW to get proper voltage. No adjustment on IAC.