Fixing a 95’ z24 for my brother in law, and its got me beat, so I’m hear to beg for help.
One day while driving it at highway speeds it lost all power and wouldn’t idle right. After getting it home and reading the computer the MAP sensor code was posted, we installed a new MAP sensor, didn’t fix it.
It threw the map code again, so we did a continuity test on the wire harness witch checked out ok.
Next we paid for a new computer/ECU. the old ones rubber seals were none existent and looked like water had got inside. Didn’t help 170 more bucks down the drain.
Did a compression test all is well.
Then I lost my head and blamed the trimming chain, after wasting 2 hours pulling the trimming chain cover off, looks great and the dowel pins line up perfect and the guides are in good shape, may change the water pump while I’m in here.
Any ideas? Sell it for scrap?
first of all
Quote:
we paid for a new computer/ECU. the old ones rubber seals were none existent
the 95 z had a recall on the seals of the pcm...so you probably couldve gotten that replaced by GM...sorry you had to buy a new one though
...
2nd...you say it doesnt idle right??? um..can you be more specific??? idles too high/too low? ..idles ruff...tries to die then jumps back up...anything like that would be great...
but right off hand id say try replacing your o2 sensor in your exhaust manifold USE ACDELCO ONLY! and then try the throttle position sensor....
but those are just guesses without knowing what kind of idle trouble your really having
Im the second person to have the joys of working this, I was told the TPS was tested and was ok.
As for the idle when it’s first started it runs fine until the idle drops to 750rpm then it starts to bounce 300-1600 till it stalls out
Uhhh don’t let it be a stupid TPS after all this.
acutally...sounds like the o2 sensor in your exhaust manifold ...go get you an AC DELCO 02 sensor for your car and replace it...should be around 17-25 bucks ...
when you start it up does it take just a minute then start to drop rpm,then jump up real high then come down slowly till it almost dies(or DOES)? if so thats probably the source....try that first then well move on to your tps since its already been tested
i think Mesra is right. sounds like the sensor is throwing wierd mix ratoios and causing it to bounce and stall.
try the IAC as well, it might be fubar.
thx for all the help, ill give all those ideas a try and get back to you all.
cheers
Are you still pulling the MAP code? If you are then I would check for vacuum leaks. As mesra said check the O2 sensor first. I had a bad IAC on my 96 3100, it idled too high. I think they're pretty easy to test with a voltmeter. I didn't have one so I just unplugged it when the idle was in the normal range and the car idled fine for 20 minutes. As soon as I plugged it back in the idle jumped back up to 2000 rpms so I knew it was bad. Does the car run fine at other speeds or is just the idle affected?
You can't outrun the radio.
i guess i shoulda told him this sooner...... lol......
if you wanna check to see if your 02 sensor is ok without replacing it simply UNPLUG IT and see how it runs...if you start it up and it runs fine then theres your problem...if it still does it move on to another...
ok update, I got the engine all back together and found a bad ground on the battery tray, after drilling out the rusted out bolt and cleaning it up it idles fine now.
But it’s still not running right, if I punch the gas the rpm raises smooth till 4000RPM then it feels like its bouncing off a rev limiter.
reset your battery...unplug it for 20 minutes
then let it idle when you start it first
If your car is not moving there is a Rev Limiter that prevents engine from over reving with no load.
Garett
if it's manual it doesn't have the rev limiter in idle. I'm guessing it's auto?
There is an idle relearn procedure for that car, check out 60degreev6.com
You can't outrun the radio.
spark plugs? mine used to stumble cause they didnt have the spark plugs spaced right and i have a 95 z thats all i gata say i just started on mine so....yeah dont noe much lol
akunamata
CHECK OUT MY DOMAIN!!
http://www.cardomain.com/ride/2236703
Ok I took it out on the road, and yup it’s fine now.
no CEL. 750rpm idle on the dot, seems to have power, slow car though.
It was the stupid ground on the battery tray.
And Garett was right about the rev limiter. Just not used to that sort of thing, guess it to stop kids from dropping it into drive to spin the wheels =)
Thanks for everyone’s help hope this post helps out some other poor sucker with a broken z24
