speedricer05

ok...i told you i'd be back...my 83' 280zxt won't start...i'm thinking it may be doing this because it's cold...the only reason i think this is because it JUST started to get cold...and that's when the problem started...i know it's a common problem with Z cars...but why? what do i need to fix to make this go away? i just want my Z back...

BoulderZ

Clogged cold start valves are bad about causing such problems and are easy to test with the FSM. However, I work nearly exclusively on '78s, so I'm not even sure if an '83 turbo *has* a CSV. I've also seen electrical systems that just don't like the cold, either (coils that don't work below a certain temp, etc.). So, maybe no spark. Try the old arc-to-the-block while Friend cranks the motor to see is you've got a spark. Got spark? Then maybe no fuel... a $1.50 for a can of starter fluid can test that. Pull the air filter out and spray starter fluid in while Friend again cranks the motor. Started? Then you weren't getting gas, probably that CSV, but... if it dies when you stop spraying, you don't get sustained gas, either (i.e. from the normal injectors). That could be a couple of things, but the head temp sensor and it's cousin the thermotime switch, et al, could be bad *or* the plug connecting to them may not have a good connection (common issue, especially with 20 year old wiring...).
Another possibility, I had an alternator that started to fail as a temp-sensitive behavior. Started cold okay, warmed up and failed. Thing is, if the alt doesn't generate a charge, it opens a relay to the fuel pump and turns it off. Oddly, that's supposed to be a safety feature to turn off the pump if you crash into something and the alternator stops spinning.
Finally, a bad fuel pressure regulator could have stuck open with the cold or who knows why. But low pressure means no spray out of Z injectors, and no starting or running. A test by putting a pressure gauge in line *to* the rail will tell you if you're getting pressure or not.
It's a lot to test, but none of it's too hard. Hopefully one of those does it for you. Good luck!
Dave

speedricer05

yeah...i was stuck by the side of the road one of the times...and i tested the coil to see if it had spark...it didn't. So, does this mean the coil has to be a certain temp to work right? if so, how to i fix it? thanks for all the tests...next time it won't start, i'll try some of those.

BoulderZ

A lot of electrical components start to fail very gradually, and very minor changes in conditions can cause them to work/fail intermittently. Temperature and vibration can be common culprits for breaking a circuit that's just barely holding together. The problem with the coil working or not at certain temperature ranges is a symptom that it's about to stop working altogether, and there isn't really any way to repair a coil, it's basically a disposable part. Though if it's stock it's now nearly 2 decades old, so it's not like it hasn't been a good part. It's just really old. Fortunately, they're not expensive. You can even get a nickel plated (chrome-like appearance) one made by Crane if you're trying to dress up the engine compartment, for about $50 US. You can probably pick up a nice (though not special in any way) basic coil at NAPA or your favorites parts counter for less than that.
Sorry to hear it it stranded you roadside! I've been there a few times and each time it's always more of a pain than I gave it credit for. For some reason, patience in working out a problem in the garage or driveway is never a problem. But roadside in the dark or cold the maximum acceptable time for a repair is about 40 seconds.
Hope your car comes around!
Dave

speedricer05

i already had a msd coil in it...but that wasn't giving any spark...so i bought an accel one...same thing...so, i towed it home that night...it cranked up fine the next morning...but died that night at work...i took it to my mechanic and he noticed the battery was not grounded to the chassis...so i did that and...knock on wood...my car hasn't given me any more problems