95 z28 that has a low end miss
#11
03-24-2010, 04:28 AM
Hey guys I'm new to the forum and have done a lot of searching but haven't quite for exactly what I'm looking for. I just bought a 95 z28 auto, motor rebuilt about 30k ago with new plugs and wires at that time
TIG- so says the seller or did you see receipts?
, opti is 2 yrs old, new tps, original coil (161k).
TIG- are you sure of this???
It idles slightly rough and rich,
TIG- rough?? here's a question, is the egr still connected? If so, either get it scanned to see if you are getting an egr code or block off the silly thing. next, have you checked for vacuum leaks and finally, replace the bad spark plug and/or cable
it kinda chugs when you get on the gas below 2k rpms,
TIG- do you mean when you slam down the pedal or when you are just trying to slowly accellerate?
above 2500 it starts to run great and pull hard. Crusin at 55mph it bucks real bad until i get the rpms up above 2500. I bought this as a spare summer toy and don't want to just start throwing parts at it cuz money is tight. I really want to get it right the first time. oh also the cats are hollowed but have been for 40k. Thanks and look forward to hearing back!
TIG- so says the seller or did you see receipts?
, opti is 2 yrs old, new tps, original coil (161k).
TIG- are you sure of this???
It idles slightly rough and rich,
TIG- rough?? here's a question, is the egr still connected? If so, either get it scanned to see if you are getting an egr code or block off the silly thing. next, have you checked for vacuum leaks and finally, replace the bad spark plug and/or cable
it kinda chugs when you get on the gas below 2k rpms,
TIG- do you mean when you slam down the pedal or when you are just trying to slowly accellerate?
above 2500 it starts to run great and pull hard. Crusin at 55mph it bucks real bad until i get the rpms up above 2500. I bought this as a spare summer toy and don't want to just start throwing parts at it cuz money is tight. I really want to get it right the first time. oh also the cats are hollowed but have been for 40k. Thanks and look forward to hearing back!
please see above prefaced with TIG
you can get a MSD coil for $39. have you
cleaned the MAF?
replaced the O2 sensors? I run NGK's without a lick of problems. GM O2's aren't the only brand that "works"
scanned for errors?
removed all the plugs to verify no cracks in the insulator and that they are in good shape? Heck, replace them, they cost $2 each.
have you replaced the wires? Again, under $40 at Jegs for 8.5mm wires
it's a 95 so your O2 sensors are before the cat
if it's stock exhaust manifold I know it's a PITA to get to the wires/plugs/O2's so it sounds like a good time for long tubes and ORY
#12
03-24-2010, 05:07 AM
Cant you just use a paperclip to get the codes on a 95? it is obd1 so you should be able to read it without a scanner. I've always read everything up to 96 with a paperclip. You can gut the cats without the ses light coming on until 96. Mines a 93 with no cats.
#14
03-26-2010, 08:46 AM
Well to answer some of the questions above. The car was a good friend of mine so I know the rebuild and parts are legit. I was excited cuz I thought it was a fpr but that only helped a little. I cleaned the MAF, replace the map, iac, fpr, pulled the throttle body and cleaned it and ran some lucas fuel treatment through it. The cats have been hollowed for 40k with no problems. I have a snap on mt2500 but can't seem to get it to communicate with the car. I think I'm gonna bite the bullet and have it scanned at a dealership so I stop chasingmy tail.
#17
03-26-2010, 08:21 PM
my 95z was doing the same thing i just put new injectors in the car and that solved my problem
#19
03-27-2010, 04:33 PM
$2 each for NGKs at advance auto parts
under $40 for 8.5mm jegs wires
if you have stock exhaust manifolds, those plugs are such a bear to get to that i would not be surprised if they aren't in tight or the boot of the wire is not connected all the way
