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HybridZ

vacuum problems?


Brian1

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Alright, so I just replaced my water pump(which for some reason made my temp gauge start working again) because my heater stopped blowing hot air. Now, I got everything back together and my heater is working, everything is fine, and I go to take my dog to the vet, I get half way down the street, and as soon as I hit about 13mph in 1st gear, the car immediatly looses all power, stops making noise, and just starts coasting until i let off the throttle a little bit, or shift up to 2nd. When I shift up to second gear, the car will go up to about 21mph, and then do the same thing again.

 

It only does it under load though, when im idling, I can rev it up just fine.

 

My car is a 1983 280zx turbo 5spd

 

new plugs, wires, fuel filter, fuel pump, air filter, cap and rotor are fine, checked my afm at the ecu, and it doesnt loose volts when the motor cuts out.

 

Any ideas?

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I had a similar problem on my 1980 Z that ended up being the B.C.D.D out of adjustment. I have a non turbo and this device in on the bottom of the throttle valve I don't know if the turbo engine has this. Another symptom on mine was high idle. Other possibilities could be the ignition module on the side of the distributor, a clogged fuel filter or weak fuel pump starving the engine, of possible misrouted vacuum lines.

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well i fixed the belt, but to no avail.

bcdd.. boost controlled deceleration device?

 

I have an open down pipe, (took off the cat) so i can hear the exhaust pretty well. when the engine cuts off, the exhaust stops making sound completely, like the car just turned off, but if I listen closely, I can still hear the engine turning in the bay, and the only sound coming out of the exhaust is the sound of my turbo slowing down. When I let off the throttle the exhaust suddenly comes back on, and the car is idling fine again.

 

Is that what your car was doing wardle?

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Might try checking your TPS, TPS connector and AFM connector. If either one got knocked loose or has corroded pins, it could cause the problems you're having. The only other thing I can think of, is the ignition is cutting out for some reason. I would check the crank angle sensor and ignition module as was already mentioned as well.

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the power transistor that makes the coil make high voltage for spark. DID you get anything wet while changing out the pump. I think I would pull the dizzy cap make sure everything dry in there. Check afm & tps connector for moisture or corrosion as above. Beyond that something got knocked loose ? during repair. Have you checked your timing? sounds kinda like what happens on a z31 when the maf goes. Have you looked at the EFI bible at atlanticz I think. Only time I had crazy stuff like that on my 83 was when I had a faulty battery. Of course this could be coincedental to the water pump but generally what is the last thing I did solves the problem.

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alright, I just checked all of my connections under the hood, and everything is connected and sending volts. I was looking at the AFM but I cant really tell where the connector to it is, I checked the voltage at my ecu, which checked out fine, but I cant really tell where the connector on the actual afm itself is. Is it under the afm? And I set my timing like a week or 2 ago.

 

as for getting things wet, yes, I changed my water pump in a bit of a rain storm actually haha.

 

Alright, Ill go check my cap and rotor, see if anythings wet.

 

As for the zclub, do you know how I might get ahold of them?

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okay, just checked the distributor and its all dry under the cap.

another thing i noticed while driving was the i gotta go up to about 11 mph, then shift to 2nd so it doesnt cut out, then go up to about 18 mph, then shift into 3rd before it cuts out again, then once I get up to about 32 mph, it will cut out and I cant go any faster even if I shift into 4th or 5th.

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Check the 2 vacuum hoses on the top of the intake, closest to the firewall, are correctly routed and not broken. Maybe try switching them. I once had a problem where my 83ZX would idle well but cut-off completely upon acceleration. Started just after an engine wash - apparently the hoses came loose during the wash and they just re-attached them.

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Dont those hoses run to the vacuum tank thing for the ac and cruise control?

 

Because one of my hoses on the vacuum tank got a tear in it, so I just cut it a little bit shorter and plugged it back in to its little T-fitting, but it didnt really matter to me because my ac doesnt work anyways.

Ill go check them out, and try switching them around anyways, thanks.

 

Can anyone tell me what the ignition module looks like and how I might test it?

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Can anyone tell me what the ignition module looks like and how I might test it?

 

Hi Brian, it is the little metal box that is mounted on the coil bracket. I'm not sure how to test it, other than swapping to a known good one.

 

The AFM connector is located on the side, but you have to pull it downwards (after removing the retaining clip).

 

Are the spark plug wires crossing? Try swapping back to your old ones, some leak EMI so bad...

 

Northwestz.org is the only Portland z-car club that I know of.

 

Hope this helps!

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Hello Brian1,

Another thought, I did get my engine wet when I had this similar problem. I also took apart the throttle and cleaned it before. the adjustment of the throttle sensor can have that effect as well The B.C.D.D. only caused my high idle. drying out everything and adjusting the TPS fixed the rpm problem. dont try to take apart the TPS I broke the cover on mine. Good Luck

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  • 3 years later...

My Z is having the same symptoms about the rev. My engine is fairly good it only has around 84000 miles on it but today something weird started happening. First gear was good and so was second at 3rd gear my car wouldn't go over 2500 rpm i would literally have my foot down on the gas and it moves like i just downshifted or something and if i keep it on the gas for to long the muffler sputters like as if a cartoon car just broke down. So i drove home at low speed from the base i work to look in my engine. I found pieces of a belt but I'm not sure where it came from. Also my gas just start dropping like a rock in water idk if that's connected to do my problem. Can somebody point me in the right direction cause nobody in panama city knows how to work on my car and i would rather get what i need to fix my car and do it myself. My engine right now is the original L28E. So would it be something close or something different altogether?

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Get the FSM from www.xenons130.com and go through the trouble shooting - eg measure the resistance of the AFM and CHTS, etc.  You may have a bad connection at the AFM - I make a kit to replace all the connectors because this is such a common problem with the S130 especially being 30+ years old.  The CHTS and AFM at two of the major sensors that can cause these problems.  The CHTS connector isn't as bad as the AFM which use usually corroded or the retaining clip is missing, etc.  Other things to check for is the ignition module on the dizzy and making sure you don't have any vacuum leaks (take the oil cap off when idling, etc).

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