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Car (with 280zx turbo engine) gradually started to die and now it only idles lean and nearly dies with any throttle


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#1 smellyfumes

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Posted 13 October 2017 - 07:09 AM

So about a week ago my car started to have issues when it got up to temp. It would originally start, idle, and run fine, but after the car began to get warm it would lean out like crazy (have a wideband installed) and there would be no response when throttle was applied under load. It did this for a few days until it decided to completely die on my way home from the gym. After a few minutes the car would start and idle lean on the side of the road, but then die immediately with any throttle (not under load). The engine is from a 1983 280zx turbo. After a little bit of research I'm wondering if it is my Crank Angle Sensor in my distributor, but I'm still very confused. I don't think it's a wet Throttle Position Sensor because I had that problem recently and I removed it/dried it out and the car ran fine. Also the symptoms are different due to not even idling rather than failing at 2000rpm.

Short video with symptoms: https://streamable.com/nn9ls



#2 datzenmike

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Posted 13 October 2017 - 08:49 AM

Fuel filter plugged?


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#3 racerx

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Posted 13 October 2017 - 08:56 AM

Next time that happens, pull over and feel how hot your ignition coil.

#4 smellyfumes

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Posted 13 October 2017 - 12:01 PM

Both my fuel filters were changed a month ago after the car had been sitting for some time. They don't seem to be clogged and I have good fuel pressure (30-55). I posted somewhere else and they also said ignition coil. Would that cause the leaning out when the throttle is applied. I'm going to look for a replacement to just be safe and check it off. Also my car doesn't seem to have a water temp sensor. Could this been deleted by the previous owner. It ran fine for the past two years without one. I thought they were necessary for the ecu like the AFM is. 



#5 racerx

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Posted 13 October 2017 - 12:47 PM

Before replacing coil, ohm it out.

#6 smellyfumes

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Posted 13 October 2017 - 12:59 PM

Sorry I should of mentioned that I had to get a tow home. The car only idles for less than 10 seconds and doesn't move. The throttle doesn't do anything. What do you mean ohm it out? Just test it with a voltmeter?



#7 racerx

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Posted 13 October 2017 - 02:10 PM

Ohm out the coil, check resistance value not voltage. Find out what the values are for your coil. Go on line on how to test coil. You do have a multi meter?

#8 Skib

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Posted 13 October 2017 - 02:28 PM

you dont have a CHTS? Thats an important part of the L28et EFI


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#9 datzenmike

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Posted 13 October 2017 - 07:35 PM

 Idle mixture is hard wired into the EFI system I believe and why there is a throttle position switch on the throttle body. It tell when the throttle is closed (idle) and when at full throttle. Full throttle ignores the sensors and O2 sensor for full performance. Anywhere between the two the fuel mixture is tightly controlled. 

 

If running lean is to be believed, maybe the throttle position switch is fooling the EFI into thinking it's idling.

 

Air is metered by the MAF. It's  very much like a swinging door pushed open by the amount of air drawn in. If stuck it will say less air when more is actually getting in and this would be lean.


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#10 Skib

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Posted 14 October 2017 - 08:50 PM

Are you running the L28et harness and ECU?


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#11 smellyfumes

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Posted 15 October 2017 - 08:40 AM

I am running the stock ECU and 83 harness. I'm also confused about the absence of the coolant temp sensor. I'll take a pic to make sure I'm not being an idiot. I have a multi meter and am going to test the coil today. I'll double check my AFM is not stuck as well and I'm going to remove and dry my TPS as well. I'll report back. 

 

thanks for the help