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94 Z28 issues

Old 12-11-2014, 01:36 AM
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94 Z28 issues

My 94 Z28 has been having a few issues lately that i haven't been able to figure out. Every once in a while the check engine light will come on after the car sits roughly idling in traffic for a while, but as soon as i start driving it again the light goes off. A few days ago as i was on the throttle, the engine all of a sudden hesitated and decelerated a bit and i heard a loud pop from under the hood, felt like the car was about to die on me but it picked back up and the abs inop light came on. And lately following that incident the car has a very strong hesitation if the throttle is pushed further than halfway, the engine backfires and a loud clicking can be heard from underneath the hood.
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Old 12-11-2014, 05:26 AM
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Re: 94 Z28 issues

Scan it for codes. Even if the light goes off, the code that turned it on is stored in memory.

https://www.camaroz28.com/forums/com...95-lt1-874306/
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Old 12-11-2014, 08:55 AM
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Re: 94 Z28 issues

I had the car scanned and looked through the history of codes. Gave a code 44, for the left o2 sensor which I replaced recently in hopes that it would fix the issue. Even after replacing the sensor I still have all of the same problems.
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Old 12-11-2014, 11:01 AM
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Re: 94 Z28 issues

DTC 44 indicates a lean O2 reading for an extended period of time. That could be a bad O2 sensor, but it could also be a wiring problem. Could also be caused by an intermittent injector problem.

After you replaced the O2 sensor, does the SES light still come on? If so, have you scanned it again for codes to see if it's still DTC 44?

After you heard the loud pop under the hood, did you check for damage - inlet air elbow torn or blown off the throttle body, vacuum line(s) blown off, damaged MAF sensor, possible damage to throttle blades or MAP sensor?

Last edited by Injuneer; 12-11-2014 at 11:05 AM.
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Old 12-11-2014, 12:41 PM
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Re: 94 Z28 issues

I didn't have a chance to check everything when it happened, but however I just checked all the sensors, tubing, lines and the throttle body. Everything still looks pretty good, as far as that goes. As for the ses light, it only comes on like 1 day every couple of weeks and only comes on in idol when I'm in traffic so it hasn't come on since I replaced the sensor, but I worry it still may. The only code it shows is the same one in the history, the 44. How would I check the injectors to see if that would be the problem? And what else should I look into?
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Old 12-11-2014, 12:54 PM
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Re: 94 Z28 issues

Also everytime I drive and push the throttle about to halfway it stutters and struggles for a few seconds, then it picks up again.
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Old 12-11-2014, 03:56 PM
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Re: 94 Z28 issues

As far as the code, clear it by pulling the "PCM BAT" fuse for 15 seconds. PCM BAT fuse on a 94 is in the fuse panel at the drivers end of the dash. That way, if you scan it again and again find DTC 44, you would know that it's still a problem and is what is turning the SES light on periodically.

Check the inlet air elbow VERY carefully. A backfire could have blown the bottom of the elbow off the throttle body, but not the top of the elbow, so it still looks intact. Also check for cracks or tears in the elbow. Air bypassing the MAF sensor can cause the engine to stumble when you open the throttle suddenly.
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Old 12-11-2014, 06:46 PM
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Re: 94 Z28 issues

I pulled the oil dipstick, and found milky oil, so I'm pretty sure it's a blown head gasket. I know there are several other things that could cause milky oil. Is there anyway to make sure that the gasket is blown?
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Old 01-14-2015, 09:06 AM
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Re: 94 Z28 issues

The hose that comes from the radiator passenger side right under over flow hose its leaking right where it connects to the metal tude . . Whats a easy fix or something
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Old 01-14-2015, 09:57 AM
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Re: 94 Z28 issues

Always better to start a new thread for your specific problem.

In any case - what year is your car? The hose for the steam tube from the back of the heads is different for 93-94, compared to 95-97.

Courtesy of Shoebox

93/94 hoses:
http://shbox.com/1/93-94_hoses.jpg

95-97 hoses:
http://shbox.com/1/95-97_hoses.jpg

Sounds like you are referring to hose #4 in the 93/94 diagram. If that's the one, and it's just cracked on the end that slips over the metal tube (part #6) you may be able to cut the split end off and reconnect the hose.

That hose was originally sold as part of the steam tube assembly, but has been discontinued. May be able to find something on ebay.

Again, from Shoebox:

1993-1994 steam pipe behind heads, incl bolts, seals and hose to radiator
GM part #10108635 (entire assembly)
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