95PurpleHaze

Ok so I finally got my toy- a 1995 z-28 6spd. When I bought the car, it was not running (owner thought the motor was blown), it turned out the cat was blocked . So Ive had the car for about 3 weeks, so far had all the fluids changed, cat is just a shell, and installed flowmasters on it. It doesn't however seem to have near the power it should- and the exhaust tips are coked black. Its at my mechanics today getting the plugs/wires changed and a K & N intake system installed, in the hopes that this will get it running right- it just seems underpowered. As a matter of fact, I had a 6 cylinder mustang automatic almost beat me- now tell me theres nothing wrong with that pictures. Ive heard alot about this MAS- could this be my problem? Its not missing- rather it just idles rough. Thanks everybody, your expertise is greatly appreciated

robsquikz28

iTrader: (246)

congrats on your new car and I have no idea wat a MAS is? Do you mean MAF like mass air flow? Why is it at your mechanics? Do you know how to work on cars or not?
how much are they charging you to perform that job?

MasterTomos

iTrader: (15)

Im sure he means the MAF...(mass airflow sensor is probably what he was thinking)...is the car throwing any check engine codes?

95PurpleHaze

Unfortunately my mechanical apttitude is about the equivalent to a monkey winning a spelling bee MAF- thats what I meant. No codes, check engine light is on when you first start it, once the motor is running nothing shows up. I had the plugs/wires cleaned yesterday and also the MAF cleaned- car had two plugs (near drivers side firewall) fouled, I drove it for about 15 mins after and honestly I couldnt tell the difference between before and after- which is strange considering it was down two cylinders previously. So we are changing the intake and throttle body today- it currently has some cheap aftermarket cold air intake on it that covers one of the two holes on the throttle body- so we are putting in a bbk 58mm and a K & N system. Any advice on where to go from here? Seems extremely underpowered for being a 5.7L. thanks

camar0corey

iTrader: (22)

Do you have the plugs/wires changed or just cleaned? That job is such a pain in the ***(sounds like the car is on stock manifolds with emissions garbage yeah?) I hope you had that stuff replaced.

Sounds like its running really rich.

95PurpleHaze

thanks. yes im pretty sure the manifolds are stock. it is running extremely rich- plugs and wires were completely changed. how do i lean it out a bit? we are putting a custom side exhaust with empty cat and slug pipe exiting on the sides through sweeper tips in front of the rear wheels today. im hoping it just isnt getting enough air in to make power so the k & n intake & the bbk 58mm throttle body should help

camar0corey

iTrader: (22)

Sounds like a neat exhaust setup, try to get some pictures and video of that!

Yeah well from your description it sounds like it was choked when you got it, hopefully now that you are getting more air in there it won't run as rich. Also was the PCM never messed with? Also if the o2 sensors are shot its going to run rich.

95PurpleHaze

Lol im outta my league here and not quite sure what the PCM is. Any way to tell if the o2 sensors are shot? We plugged his diagnostic tool into the comp under the dash, couldnt get a reading all it said was "fail". J

defaultexistence

iTrader: (11)

you need to do a compression check on those cylinders that you said in your other post and i quote: "two cylinder plugs were fouled and wet with oil." before dropping another dime into it ...if those cyl's arnt compressing because of rings or head gasket, you have bigger issues and low/no power kina like a v6. all that fancy **** aint gonna fix it it will runn shittier cause it will then need a tune AND be ****'d up...do things rite the first time when it comes to mods&motor get your power-train in check first...my 2cent
p.s. it also sounds like you need new o2's

big_bird_93

iTrader: (1)

Seeing as how the cat was clogged i would say the 02's didnt get any attention from the previous owner. I would replace them.

mrchyzy16

iTrader: (1)

Yea i vote for o2's as well. When they go bad, the computer trys to compensate by adding fuel and retarding timing. Which means less power and bad gas milage.

95PurpleHaze

I just got done looking at it from the underside on a lift. These have two O2 sensors? We only saw the one, on the left front side- it appeared to be new. Also found out Warrior motorsports of Carlisle PA (tag on bottom of block) did the short block work, bored to .30 over. Didnt realize there are two O2 sensors- where would I find the other one

b1gwi11

There should be at least 2, one on either side. My 94 only has 2, I know later years had 2 in front of the cat, and 2 after the cat, but I'm not sure what year they started putting the second 2 on.

FASTFATBOY

iTrader: (23)

Dont put that 58MM throttlebody on, it requires manifold modification. Leave the stocker on it for now.

It may have burned the ex valves on the 2 drivers side cylinders where the plugs were fouled. Do a compression test. When the converter gets clogged and people continue to drive thats what happens sometimes.