CTZCC.COM
http://forums.ctzcc.com/

Backfires on start up, 80 280ZX
http://forums.ctzcc.com/viewtopic.php?f=4&t=9512
Page 1 of 1

Author:  Tomwas1 [ Tue Sep 11, 2018 9:45 am ]
Post subject:  Backfires on start up, 80 280ZX

Usually takes two to three tries before she starts, once started if I step hard on the pedal it will hesitate and backfire until it runs a couple of minutes. Did complete tune, rotor to plugs everything in between, Installed new fuel filter. Still same scenario, any tips, ideas,suggestions. Once it warms up it runs great. Thanks

Author:  Frank T [ Tue Sep 11, 2018 10:01 am ]
Post subject:  Re: Backfires on start up, 80 280ZX

Howie, you wanna tell him what you did when yours did this?

Author:  Tomwas1 [ Tue Sep 11, 2018 8:40 pm ]
Post subject:  Re: Backfires on start up, 80 280ZX

I did search the tech forum and found nothing on these symptons.

Author:  Paul [ Wed Sep 12, 2018 5:49 am ]
Post subject:  Re: Backfires on start up, 80 280ZX

Sounds like the Mass air flow needs an adjustment, as long as all other sensor are working properly, like coolant sensors to the computer. First thing is to pop the cover off, that will take some patience. A razor blade or tiny screw driver to get the glue off and eventually it will pry off. Then you loosen the screw that holds the spring wheel. Very important :arrow: Have you finger on the spring wheel so it dont go twang on you. Not a total big deal if it goes twang, just have to wind it back up until it's close to were it should be, basically to where the car runs. So all you need to do is just let some tension off, so back it off about 3-5 teeth and try it out, sometimes a little more. This has always solved any hesitation issues with any ZX I ever had..................and I can't remember how many I had. :roll: BTW you will also clean the carbon pad that the needles ride on with a Q-tip and some rubbing alcohol. Look at it carefully to make sure the carbon has not worn through. If so, then Houston, we got a problem.

Author:  Tomwas1 [ Thu Sep 13, 2018 11:42 am ]
Post subject:  Re: Backfires on start up, 80 280ZX

Wow :shock:

Author:  Frank T [ Thu Sep 13, 2018 5:24 pm ]
Post subject:  Re: Backfires on start up, 80 280ZX

Uhh, Howie.......?

Author:  HowardJ [ Thu Sep 13, 2018 10:14 pm ]
Post subject:  Re: Backfires on start up, 80 280ZX

Frank T wrote:
Howie, you wanna tell him what you did when yours did this?


Frank this is a straight six and my 1985 is a V6 fuel injected 3.0 so I'm not sure if my solutions will help.

What Frank's thinking about with my car may be one of two issues I had/have. I had carbon build up on the contact points inside the distributor cap so I scraped them with a small file until they shined. Did you change the distributor cap? An old cap can also develop a hairline crack that would cause your hard start issue. A bright light shined inside the cap might reveal what looks like a pencil line along the wall of the cap. This fixed the "pulsation" that I had while trying to maintain a constant highway speed.(Not your issue!) The other issue was a cold engine "stumble" that was a malfunctioning vacuum solenoid that is electrically controlled to stop/regulate vacuum flow, for the first three minutes, to the fuel temperature sensor in an initial cold start up. This blocking of vacuum allows a richer fuel mixture while the engine comes up to operating temperature. This condition in the 84-85 models causes a lean mixture condition and stumbling. So I'm not sure how this might help with your issue if you don't have similar components.

As far as the excessive cranking before it starts my guess would be that there is moisture inside the distributor cap. If you remove the cap look for moisture droplets or dark "dots" or "specks" which would be dried water droplets with carbon powder in it. The running engine warming up and the movement of the rotor evaporates the moisture and stops the "arcing" inside the cap (which makes the engine run like crap) until there's no more moisture (2-5 minutes).

If this doesn't help you or was a total waste of your time and mine we can always blame Frank T. for having write this long response. :lol: :shock: :mrgreen: Good luck .

Howard J

Author:  Frank T [ Thu Sep 13, 2018 10:46 pm ]
Post subject:  Re: Backfires on start up, 80 280ZX

Haha! :lol: OK Howie, good points. I thought you guys were driving similar cars for some reason. Mea Culpa, Nolo Contendre, Probis Obiscus, Habius Corpus, Ante Dominus, Santo Somalia amigo.

Author:  Tomwas1 [ Fri Sep 14, 2018 8:50 am ]
Post subject:  Re: Backfires on start up, 80 280ZX

Thanks Paul Frank and Howie. Mine is fuel injection, probably has similar components. As I posted, I did Complete ignition tune, same symptom before and after. I'm living with it, after a few minutes warming up it runs like a 280zx should. I appreciate everyones help and suggestions. :) :thumbs_up:

Author:  Paul [ Fri Sep 14, 2018 10:39 am ]
Post subject:  Re: Backfires on start up, 80 280ZX

If it runs good after warming up I wouldn't worry too much about it. If it gets to ya, then clean terminals to coolant sensor for computer, and then move onto the AFM BTW the 300zx has a different MAF and non adjustable. Th Z31 might be a better system per say, but so far the record for breaking down due to a Dizzy sensor going bad, or the MAF goes bad sure out weighs the 280zx. The 82-83 turbos are the only Distributors I ever seen just quit on you. It's not very common for these cars, but it can happen. EX: When my fathers Pathfinder broke down in Vermont, (same dizzy,) I just brought me up a couple Dizzys I got cheap at the junkyard and brought back the pathfinder. First Dizzy did the job. :thumbs_up:

Author:  mikeatrpi [ Sun Sep 30, 2018 7:23 pm ]
Post subject:  Re: Backfires on start up, 80 280ZX

Hi Tom! Is there any change if you unplug the cold start injector? Its the extra fuel injector on the intake manifold.

Author:  Tomwas1 [ Tue Oct 02, 2018 8:40 am ]
Post subject:  Re: Backfires on start up, 80 280ZX

Will try that mike. Thanks

Author:  Tomwas1 [ Tue Oct 02, 2018 12:35 pm ]
Post subject:  Re: Backfires on start up, 80 280ZX

Mike, tried it, no change.

Author:  mikeatrpi [ Tue Oct 02, 2018 5:46 pm ]
Post subject:  Re: Backfires on start up, 80 280ZX

Tom I have an AFM, and I think a distributor too, out of my 82 NA. I don't know if they'll fit your car, but you're welcome to try the parts and find out if they help or not.

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/