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Car starts but dies when reved


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I have done a lot of reading so far but Im still not sure whats wrong. The car starts and runs but as soon as you start giving it gas and putting it in gear to drive I loose all power all and the lights dim. The motor gets really jerky. It started when driving at about 70mph steady on the highway and was intermittent for a while after that until it was all the time. It is an L28 motor that I have started removing some egr parts and plugging everything I removed. I have a spare alternator and it has been suggested that is the problem but im not sure. I always thought that the alternator just led to a drained battery and a car that wouldn't start not something like this. Also there is a relay or a wiring connection behind the glove box in the dash that is clicking and once I got the glove box out it was sparking. I will try and get a picture of that but Im not sure if the problem is related or not. I will also try to look in the book and post what part I think it is that is clicking and sparking. Any help would be greatly appreciated. I should have time tomorrow to do the alternator and test that theory.

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There is not enough information.

 

You need to provide details e.g., year/make/model of car, carb or FI, specific mods that you have done etc.

 

Have you checked battery voltage? A discharged battery can cause the symptoms you listed.

 

Sparking relay - get a schematic and find out what the relay does. Do a search as members have posted schematics.

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Sorry I have been having computer trouble too so I was trying to get as much of the problem as possible in there. Its a 1980 ZX FI no real mods yet just cold air intake and a hacked off muffler. The gauge for the battery voltage has been high since I got the car and sometimes it has had trouble starting on hills. I don't know if that helps at all.

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Ok so from the repair manual the relay that is clicking is either the seat belt warning, the fuel pump relay 1 or one other thing that my mind is drawing a blank on. We hooked the battery up to another car that was running and still had the same problem so that further takes me away from alternator. The AFM flap operates smooth. We pulled the distributor apart and everything in there looks clean, a little bit of wear was on one of the connections but we sanded it off and still had the problem. I need to get this car running again soon the weather is to nice not to drive it. Any other suggestions? Oh and I am not finding any vac. leaks either.

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Try typing "280ZX dies" into Google. You should get a large number of hits with your specific problem. What you are describing appears to be a common problem for the 280ZX.

 

Also, try the ClassicZ Club website. They specialize in stock Z cars and have probably delt with this problem.

 

Do you have a Haines 280ZX manual? Follow the procedures for working on the fuel system.

 

Post back here when you find the solution to help others who may have the same problem.

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Ok so from the repair manual the relay that is clicking is either the seat belt warning, the fuel pump relay 1 or one other thing that my mind is drawing a blank on

 

 

I think you're onto something with the fuel-pump relay. Especially if it's sparking, it could be shorting and grounding something out (hence why it seems to effect the entire electrical system). It would also cause your car to stumble, since it's FI any drop in fuel pressure would be immediately noticeable in engine operation.

 

After doing some reading on random google results for "280zx dies" (as Miles suggested), it seems it has a lot to do with the +12v coming from the ignition switch. My guess is that your coil, starter and fuel pump relay are all tied together somewhere on those circuits (the "start" and "run" positions on your ignition lock cylinder switch) and maybe that sparking relay has something to do with it.

 

Also, have you checked your ignition module?

Edited by kamikaZeS30
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I have had a lot going on this week so I haven't had as much time to fool with the car as I wanted. All these suggestions are very helpful and it looks like I have plenty to read about on this rainy day now. Thanks guys and I will be sure to post what had to be done to fix it.

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I did that google search and read about 5 of the threads that came up. It seem like everyone's car dies and then they have to wait to get it to start again. The motor doesn't actually die, so that was my fault on that one. The rpms drop out and the throttle becomes unresponsive until you get off of it and let the motor even its self back out. I hear it sucking air, so I have a pretty good feeling its that fuel relay. The only thing that keeps me feeling a little funny about that is sometimes I smell gas after we rev it. Looks like Im taking a trip back to the junk yard tomorrow. They have an 82 or so zx in there, hopefully it has the same relay.

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I did that google search and read about 5 of the threads that came up. It seem like everyone's car dies and then they have to wait to get it to start again. The motor doesn't actually die, so that was my fault on that one. The rpms drop out and the throttle becomes unresponsive until you get off of it and let the motor even its self back out. I hear it sucking air, so I have a pretty good feeling its that fuel relay. The only thing that keeps me feeling a little funny about that is sometimes I smell gas after we rev it. Looks like Im taking a trip back to the junk yard tomorrow. They have an 82 or so zx in there, hopefully it has the same relay.

 

 

Is your 280ZX equiped with a fuel pressure regulator? Try a search on it.

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I would imagine so. Looks like Im gonna have to try and find out how to check it. Unless you know and wouldn't mind sharing? I might just pick one up from the junk yard today just to be sure. Should only be about 5 bucks.

 

 

Check out a Haines manual for a 280ZX. There might be a section on checking out the fuel pressure regulator.

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Ok so I picked up a new relay at the junk yard and still have the same problem. That was something quick to try. I will try and swap the fuel pressure regulator some time tomorrow hopefully, and possibly the alternator. Would the voltage regulator going bad have the voltage to high or to low though?? Computer is still acting funny so Ill check back when I can.

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The haines manual only has removal and installation of the regulator. I have a spare one laying around so after I swap the alternator its on to that. I have the alternator pulled off but not out yet, didn't realize what time it was when I got started and ran out of day light. Tomorrow though it will be out and hopefully swapped. The spare alternator looks a little bit different so Im going to have to compare them before I put it in.

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  • 3 weeks later...

So it turned out to just be the alternator. I swapped it out along with a few blown fuses this past weekend and everything has been running just fine again. No more sparking clicking relays, no loss of power when driving. Next broke part that needs fixing/ replacement is the brakes. Its funny though because now that the car is fixed and working fine again, the computer is working just fine again too. Nothing was done to fix that though, it just decided to stay on now.

Edited by CaptainJoe87
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  • 3 weeks later...

the ECU is working properly now because the entire wiring harness is getting the appropriate amount of power generated thoroughly through it for everything to work efficientally. always check your battery cables, fuses, and grounds when trouble shooting an electical problem first. 9 times out of 10 it will be one of those three things and you can save yourself alot of headaches. get a test light and a multimeter on the cheap and learn to use/love them because they can save you alot of money and time.

Edited by brucevilanch
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