My 87 z28 is driving me nuts! off of the line it hesistates so bad for a good second or two that people on a four way stop think that i am letting them go. if i step on it my tranny knocks because my bushing is broke. I bought a tranny mount and i bought an o2 sensor, but will that be enough to get rid of this hesistation?

87 z28
305 4 barrel rochester

 

Go ahead an fix that bushing... best not to break your tranny... as for the hesitation, install the O2 sensor, if it doesn't go away, clean out your intire throttle body and as much down into the intake as you can... they get gummed up after a while... if it still does it, set your timing. Two degrees stronger than factory spec should be safe, any more than that and you'll need hi-oct.

also I assume regular maintanence parts are in pretty good shape (spark plugs... cap + rotor, ect.)

95% says that solves the problem.

------------------
1985 Camaro SC - 2.8L, auto.

Mods:
Removed air baffles, mandrel bent cat-back pipes (but stock replacment muffler, Dynomax Turbo and Catco converter are on thier way)

 

Don't worry about cleaning out the throttle body....you don't have one. 305 Q-Jet right? I would suggest getting some carb cleaner and clean that sucker out. Something tells me you are running too lean, and your car is hesitating from too much air but not enough fuel. Check fuel pressure. If the pressure is low...get a new fuel pump. Are all your vacuum lines connected? Is the EGR working properly? These are all things to check out. I couldn't tell you one way or the other the exact diagnosis. But I just have a feeling you are running lean. Get back to us on that. Thanks.

-ws6formula-

------------------
1989 Pontiac Formula WS6
69,000 miles.
------------------------
305 TBI, 4.10 gears, SLP Zexel/Torsen Limited Slip Differential, 700r4 B&M TransPak, LT4 Hot Cam/Valvesprings, GM Aluminum Driveshaft, 2700 RPM Stall, Edelbrock Performer RPM intake manifold, Turbocity TB. Ran on 6-19-2001 again: UPDATED: 14.1 @ 97.68 mph. Dyno'd Bone Stock @ 172.6 rwhp, 266 ft-lbs. of rw-torque.

 

Oh yeah, install that O2 sensor. It couldn't hurt, but I don't think it will completely clear all of your problems. I think your problem is fuel delivery. Your transmission is knocking? Or is it banging on the underbody? If it's banging, then get a new tranny mount. If it's knocking, get it checked out. I don't think your tranny has anything to do with this hesitation you are having. Check out your Air/Fuel ratio, and set them to stock specs and see if that helps you.

-ws6formula-

------------------
1989 Pontiac Formula WS6
69,000 miles.
------------------------
305 TBI, 4.10 gears, SLP Zexel/Torsen Limited Slip Differential, 700r4 B&M TransPak, LT4 Hot Cam/Valvesprings, GM Aluminum Driveshaft, 2700 RPM Stall, Edelbrock Performer RPM intake manifold, Turbocity TB. Ran on 6-19-2001 again: UPDATED: 14.1 @ 97.68 mph. Dyno'd Bone Stock @ 172.6 rwhp, 266 ft-lbs. of rw-torque.

 

thanks for the replies guys. anyways, im running really rich and tonight when i was driving around my car really began to miss. the tachometer was bouncing up and down between 500 and 750 rpm at idle. i had no power and my missing got worse the faster i went. i think this hesistation problem is just getting worse. I just changed the plugs and the wires yesterday, could it be that one of the plugs is bad? right after i changed the plugs all of my problems went away for last night, then this morning it all came back, then tonight it got really bad. any help would be greatly appreciated, thanks

 

It sounds like your car is choking upon throttle because you are running lean. Rich wouldn't be what you are describing. I don't think it has to do with anything with the ignition. As far as the tach jumping at idle...I think it's your EGR system. Maybe you are running to cold of a spark plug? I don't use anything but AC Delco plugs and wires, they don't get much better than those. I would just suggest getting it checked out anyway. I can't diagnose it from my computer screen, other than those suggestions...I'm all out of ideas. Any others fellas? Thanks.

-ws6formula-

------------------
1989 Pontiac Formula WS6
69,000 miles.
------------------------
305 TBI, 4.10 gears, SLP Zexel/Torsen Limited Slip Differential, 700r4 B&M TransPak, LT4 Hot Cam/Valvesprings, GM Aluminum Driveshaft, 2700 RPM Stall, Edelbrock Performer RPM intake manifold, Turbocity TB. Ran on 6-19-2001 again: UPDATED: 14.1 @ 97.68 mph. Dyno'd Bone Stock @ 172.6 rwhp, 266 ft-lbs. of rw-torque.

 

i used bosch platinum plugs, and im not very satisfied with them. for the wires i went with the 7.5 mm autolite, which arent anything special. ive had this little tiny plastic line that connects to something between the sixth and eight spark plug, down there somewhere and it has been split in two and has since melted, could that be a problem?