1994 z28 shuts off while driving
#1
1994 z28 shuts off while driving
Thanks in advance for helping. I bought this z28 about 2 weeks ago and it ran great ( just rebuilt engine with a few mods) I had been using premium gas it since I had it I had to get some at a place I don't usually get gas for it at but was low so I got some and made it about 2 miles and the car quit it would kinda try to start but no rpm and acted like it was missing. I towed it home and it started so I drove it around and after a while 10 min. maybe it quit like someone cut the key off. it started back but low rpms and the missing but cleared up and run great. it has done this 2 or 3 times in the last few days. one time it would not start for about 10 minutes. I thought bad gas so I added some octane boost to it and other things to it but still the same yall think bad gas?? or what. it doesn't run hot but the driver side fan doesn't work.. I am still checking on it.
#2
Re: 1994 z28 shuts off while driving
Octane boost isn't going to cure dirty or water contaminated fuel. Fill it up with new fuel. While 87 octane will produce reduced engine power, the engine should still operate satisfactorily.
Check the fuel pressure. Contaminated fuel could have affected the filter. Fuel pressure should be 41-47psi with the engine running, and the vacuum compensation line of the fuel pressure regulator. Reconnect the vacuum line, and the pressure should drop by about 8psi.
Shoebox has a photo of the fuel pressure regulator components and the Schrader valve where fuel pressure is tested:
http://shbox.com/1/fp_reg.jpg
Has the SES light come on at any time? Do you have a way to scan it for codes? Requires an older style Auto Xray OBD-1 scanner, or software like Scan9495. Unlike the 1993 and earlier models, you cannot flash the codes on the SES light by shorting the ALDL connector. There are a couple codes that do not turn on the SES light.
https://www.camaroz28.com/forums/com...95-lt1-874306/
Scan9495 can also log the PCM for a period of time, and we can help you review the data log file for problems.
If you have an "early" 1994 model, one fan comes on at 226*F, and the second fan does not come on until 235*F. "late" models have both fans running, first both on low speed, and then both on high speed. There are codes for the fan relay circuits.
This diagram shows the two variations of fan control:
http://shbox.com/1/1995_pcm6.jpg
Check the fuel pressure. Contaminated fuel could have affected the filter. Fuel pressure should be 41-47psi with the engine running, and the vacuum compensation line of the fuel pressure regulator. Reconnect the vacuum line, and the pressure should drop by about 8psi.
Shoebox has a photo of the fuel pressure regulator components and the Schrader valve where fuel pressure is tested:
http://shbox.com/1/fp_reg.jpg
Has the SES light come on at any time? Do you have a way to scan it for codes? Requires an older style Auto Xray OBD-1 scanner, or software like Scan9495. Unlike the 1993 and earlier models, you cannot flash the codes on the SES light by shorting the ALDL connector. There are a couple codes that do not turn on the SES light.
https://www.camaroz28.com/forums/com...95-lt1-874306/
Scan9495 can also log the PCM for a period of time, and we can help you review the data log file for problems.
If you have an "early" 1994 model, one fan comes on at 226*F, and the second fan does not come on until 235*F. "late" models have both fans running, first both on low speed, and then both on high speed. There are codes for the fan relay circuits.
This diagram shows the two variations of fan control:
http://shbox.com/1/1995_pcm6.jpg
Last edited by Injuneer; 08-11-2015 at 09:15 AM.
#3
Re: 1994 z28 shuts off while driving
thanks a lot I will ck the fans again the ses light has not come on. I just cked the driver side fan and it is pluged in and not froze up. sorry it takes a while to get back to yall I work strange hours
#5
Re: 1994 z28 shuts off while driving
sorry it took a while to write back had to work the a/c does not work right now the people who rebuilt the engine goofed up the threads on the low pressure line where it goes into the a/c part in the fire wall. working on emptying the fuel tank today... thanks again for the help
#6
Re: 1994 z28 shuts off while driving
I got a chance to empty fuel and put in a few fuel filter. cranked right up. have not had time to drive it much. when you work 60 to 70 hrs a week there isn't a lot of time left to check on things. again thanks a lot.
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