91 Festiva Electrical short

[koRnhead]

well you can wire in any large relay and it will do the job.....that happened to my Dad's festy, driving down the road and bam just nothing!! turned out to be the relay, and we just wired in one out of a 300zx we had laying around.

[koRnhead]

you are carbed correct? otherwise I would take a look at the VAF, they do funny things when they go bad!

[Spike]

you are carbed correct? otherwise I would take a look at the VAF, they do funny things when they go bad!

Front first post, first words:

Jus baught a 91 efi 5 speed

In other words, check the VAF. :p

[koRnhead]

Right at least check the VAF! I had gone to Culvers one night, fine as can be, leaving it suddenly bogged like the intake came apart. Then finally just died altogether. The kicker, that may relate to you is my voltmeter was reading 12v even tho the alternator was fine.....changed the VAF and all was well again.

[tooldude]

That sounds like a possible ignition switch problem, loose or burned contacts. Most shorts are not going to undo themselves without physical movement, burning through, or blowing a fuse. There may not be a short. You need to explain "won't run when it's shorting" - it won't crank or it cranks and won't fire up. It sounds a lot like an intermittent connection. So how do you get it to finally run then, jiggling the switch? If you turn on EVERYTHING on the car, one thing at a time, is there anything that doesn't work properly?

[Jblair]

The problem iisintermittent, i baught the car and couldnt get it to fire, it cranks perfect, i towed it home and when it was the in the driveway it fired up. It died after about 30 seconds, when it died everything seemed to surge ie dome light dimmed quickly, head lights dim. I checked battery with a test light and it had a dim glow, i know something grounded. So far everything seems to work, electronic (stupid) shoulder belts has a issue so i pulled the fuse. I check the spark, it doesnt consistantly spark, the w by whole system except distributor is new. Ignition switch and main relay are kinda what im thinking. The reason i know its a short, the battery is draining if it stays connected and it also runs the batteru hard if key is in hot. Having to write you on my phone. Kinda hard

[koRnhead]

I would try a VAF just to see.....

[Jblair]

Ok, just took column apart, ignition switch is marked with u pull it colors. They got inhere before. Wires look ok, some minor corrosion but doesnt apear to be enough to cause the issue.

[Jblair]

I would try a VAF just to see.....

what is vaf, that vehicle air flow would cause short?

[Jblair]

Ive opened up the harness from main relay all the way to battery cable, wires are in great shape. I cleaned all connecters from main fuse panel to all connectors off main harness. Im charging mybattery, cranking so much its running low. Any other ideas where i should go? Im thinking ill clean all ground contact points to engine. I think slight corrosion in the whole system could be causeing enough resistance to stop spark. Seatbelt system has a short, but there is still a short somewhere in the system as far as i can tell, i dont know why its aintermittent loss of spark. Stumped!

[tooldude]

I can't believe you could have a short large enough to cause a no-start and yet not blow a fuse, unless the battery was very weak. Yet you say the car cranks OK. A short completely outside of the fuse protected circuitry would have to be between the B+ post and the exiting terminals in the main fuse box where the former fusible links connected. That would be a direct B+ short to ground that even a moderately strong battery might burn out. There may be more than one problem, concurrently, so that ignition problem could be a separate issue. If something is staying 'ON' you will have to find that circuit. It may be best to start with the ignition switch to make sure it's not powering a terminal when it should be off. Also, if you know there's a problem with the seat belt system, unplug the passive restraint module and see if that is what's staying 'ON'.

[Jblair]

Awesome insight. Thank you for the advice. I took the seat belt 30amp fuse out, draw stopped. No fuses burnt or blown and ignition switch wiring looks ok. You help me rule out the shorting concept. Do you know how the main relay could fit in this equasion? It was suggested to bypass the relay as a test to see if it would work. Im not sure witch of the 4 wires to connect. Tried following from the schematics, just not sure. Tried to find a new relay to throw at it, they dont have one. Im wondering if there is alternative make that would swap? Also i was considering making a relay with the old pigtail and creating a connecter. I may be on a goose chase with that idea but im narrowing down to a few components that could fail in this scenario. After battery fully charges and i clean a make new block ground, im out of ideas. Guy that worked on this before me threw parts at the car but missed a few basic diagnostic peices including changing spark plugs way over due with plug wires corroded to plugs.

[koRnhead]

Yes any relay will work, from another car. And yes the VAF is the air flow meter. But that silly thing has a lot to do with our little cars starting. And ive seen them do very odd things to drivability when failing. Simple enough to try if you can find another in a JY or a local member.

[tooldude]

What is your suspicion with the main relay as removing the seat belt fuse stopped the current draw? (Did it stop ALL current draw, do you have an ammeter to test it?) I take it the car is still not starting, maybe just a tuneup problem.

[Jblair]

Im not sure if the problem will be solved ive got to try today. Current draw stopped at belt fuse removl. The entire ignition system is new. New iggy switch, new coil, new iggy module, cap rotor, wires, plugs, previous fuseable links now cartridge fuses, the main relay is a ugly beast, relays being.mechanical devices tend to go out, 20yrs of use makes me suspicious. I let battery charge over night, i may see a live car today.