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Discussion Starter · #1 ·
My 1981 280zx non-turbo has a problem of very hard starting only in the winter months! It seems like its getting too much fuel and is flooded. It does eventually start but you have to rev it up to clean it out. It does not have this problem in the summer at all! Please help me!
 

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Discussion Starter · #2 ·
> My 1981 280zx non-turbo has a problem of
> very hard starting only in the winter
> months! It seems like its getting too much
> fuel and is flooded. It does eventually
> start but you have to rev it up to clean it
> out. It does not have this problem in the
> summer at all! Please help me!

Have you adjusted the valves? The colder the engine, the less valve lash there is. Possibly to the point that they aren't closing all the way when cold. I don't think that is very likely though, since they would have to be adjusted pretty tight, but I've heard of that happening.
 

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You'll need a manual!

Your description indicates a fault somewhere in the cars cold start system. I assume it starts OK when it's 60°F or warmer outside?
If it is a cold start system problem then it could be:
1) Faulty air regulator - this adds additional air during cold start up and will cause you to run rough (rich) if it is stuck closed.
2) Engine temperature sensor circuit - this tells the ECU that the engine is cold and it increases the pulse duration on your 6 main injectors. If this fails you will belch huge clouds of black smoke, gas foul and die forever.
3) Thermotine Switch - this tells your cold start injector (7th injector - located on your intake manifold) to fire. This would be a problem running rich after start-up but not during.
4) AFM - idle switch and air flow sensors in AFM could be sending erroneous signal

You could also just have a bunch of corroded electrical connectors that need to be cleaned. Get a can of electrical contact cleaner at the auto parts store and take a Saturday morning to pull all your connectors apart and thoroughly clean them. YOu may not solve this problem but the car will probably run a lot better in other ways.
Phantom
 

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Re: You'll need a manual!

> Your description indicates a fault somewhere
> in the cars cold start system. I assume it
> starts OK when it's 60°F or warmer outside?
> If it is a cold start system problem then it
> could be:
> 1) Faulty air regulator - this adds
> additional air during cold start up and will
> cause you to run rough (rich) if it is stuck
> closed.
> 2) Engine temperature sensor circuit - this
> tells the ECU that the engine is cold and it
> increases the pulse duration on your 6 main
> injectors. If this fails you will belch huge
> clouds of black smoke, gas foul and die
> forever.
> 3) Thermotine Switch - this tells your cold
> start injector (7th injector - located on
> your intake manifold) to fire. This would be
> a problem running rich after start-up but
> not during.
> 4) AFM - idle switch and air flow sensors in
> AFM could be sending erroneous signal

> You could also just have a bunch of corroded
> electrical connectors that need to be
> cleaned. Get a can of electrical contact
> cleaner at the auto parts store and take a
> Saturday morning to pull all your connectors
> apart and thoroughly clean them. YOu may not
> solve this problem but the car will probably
> run a lot better in other ways.
> Phantom

let me add to this if you take the cleaning approach like Phantom said, that you also buy some di-electric grease and coat those shiny clean contacts you worked so hard on. i did this on everything from the injector harness (engine was missing badly) to those pesky temp sensors (very touchy!!) to bulb sockets. EVERYHING on these cars could use a healthy dose of this stuff.i don't know how they did it, but the Japanese managed to copy the Prince of Darkness (Sir Lucas) himself!!!
 

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Nissan Harness +20 years = Lucas

> let me add to this if you take the cleaning
> approach like Phantom said, that you also
> buy some di-electric grease and coat those
> shiny clean contacts you worked so hard on.
> i did this on everything from the injector
> harness (engine was missing badly) to those
> pesky temp sensors (very touchy!!) to bulb
> sockets. EVERYHING on these cars could use a
> healthy dose of this stuff.i don't know how
> they did it, but the Japanese managed to
> copy the Prince of Darkness (Sir Lucas)
> himself!!!

True - but it takes about 20 years for the Nissan harnesses to reach a level of non-reliability that the Lucas harnesses can obtain in about 18 months.
Good tip on the di-electric grease. Radio Shack??
Phantom
 

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Re: Nissan Harness +20 years = Lucas

> True - but it takes about 20 years for the
> Nissan harnesses to reach a level of
> non-reliability that the Lucas harnesses can
> obtain in about 18 months.
> Good tip on the di-electric grease. Radio
> Shack??
> Phantom
Hey Phantom,

Been There, Done That, Am Wearing The T-Shirt At Work Tonight. On the back, the Lucas three position switch Dim, Flicker, & Off.
Old Lucas snicker. What is the best use for a Lucas refrigerator? Baking a roast.
:) mikey
 
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