Fuel and Ignition Fuel Pumps and Systems, Ignition and Spark Systems

1995 z28 runs and then dies

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Old Dec 9, 2009 | 10:22 PM
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Angry 1995 z28 runs and then dies

I have had this problem for about 4 months. It will run from anywhere between 15 and 30 mins, but then it dies. Then after it dies it won't start again for about 2 hours or so, and then it does the same thing all over again. It also failed a light noid test. I've asked all around about the problem, but no one can be for sure what is the problem. It has a brand new ecm and the distributor was replaced last November. So if anyone could help I would really appreciate any ideas.
Old Dec 10, 2009 | 05:27 AM
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Have you scanned it for codes? Have you checked the fuel pressure? Was the distributor replaced before or after the problem (not clear whether "last November" = 2008 or 2009)? By "failed a light noid test" do you mean that you did not get injector pulsing when it wouldn't start? There are some codes that will shut down the injectors.

Is the engine stock or modified?
Old Dec 10, 2009 | 10:15 AM
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injuneer

I did scan it but the scanner says no link. Checked for fuel pressure and its fine. The distributor was replaced in 2008. As for the light noid test, it fails when I'm trying to crank it after the car dies. The engine is stock. Also I don't get a check engine light which probably explains why the scanner doesn't link up. I've also checked every fuse. thanks for the help
Old Dec 10, 2009 | 10:26 AM
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When did you check the fuel pressure, right after it stopped running, or after it had cooled off?
Mine was doing the same thing at one point. I would wait until the engine cooled and checked the pressure, it was fine at about 43 psi. Then I checked it right after it died, still hot. Around 5 psi. The pump was overheating and failing, but when it cooled off it was fine. Just my experience.
Old Dec 10, 2009 | 04:02 PM
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I did scan it but the scanner says no link.
The '95 has an OBD1 PCM but has an OBD2 ALDL connector under the dash.. Did the person doing the scan set up for OBD1 or look at the ALDL connection and incorrectly try to scan an OBD2 ?? This is a very common problem with the unique '95 setup. Your stalling problem is looking like opti, ICM or coil. Not saying to go after parts, but these parts in our f-bodies causing stalling and then running after cooling down are fairly common on the forums. Ya really need to figure out how to fix the scanning problem..

Last edited by bobdec; Dec 10, 2009 at 04:06 PM.
Old Dec 10, 2009 | 05:36 PM
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my experiences would say fuel pump or coil..
Old Dec 14, 2009 | 03:24 PM
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checked fuel pressure before and after and it's fine.
Old Dec 14, 2009 | 09:47 PM
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Originally Posted by jman1093
I did scan it but the scanner says no link. Checked for fuel pressure and its fine. The distributor was replaced in 2008. As for the light noid test, it fails when I'm trying to crank it after the car dies. The engine is stock. Also I don't get a check engine light which probably explains why the scanner doesn't link up. I've also checked every fuse. thanks for the help
Not all codes turn on the SES light. DTC 16, for loss of low resolution cam position signal from the Opti shuts the fuel system down, but it does not set a code. You don't have to have an SES light or an active code for a scanner to connect. I suspect your scanner connection problem is exactly as "bobdec" explained. You need to use an OBD-I scanner, either with a 12-pin/16-pin adapter plug, or jumper wires, as shown on Shoebox's site:

http://shbox.com/1/xraycable.jpg
Old Dec 18, 2009 | 11:06 PM
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just took off the intake hose and found that it was melted on the bottom. Could this cause the engine to run and die, and if it were to die would it take it a while to crank back?
Old Dec 19, 2009 | 10:20 AM
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By "inlet hose",do you mean the big rubber elbow (bellows) that connects the MAF sensor to the throttle body?
Old Dec 23, 2009 | 08:58 PM
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Yes the hose from the throttle body to the MAF sensor. Could this cause the problem?
Old Dec 23, 2009 | 11:02 PM
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Could be a problem, since it allows air to bypass the MAF sensor, and the PCM uses the mass flow reading from the MAF sensor to determine how much fuel to add.
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