Ok, I've been having this problem for quite some time now and no mechanic has been able to identify the cause. First off, I have a 1990 300zx n/a which I bought from a prior owner that used to run NOS in the engine with JWF ECU. Here's the problem- Whenever it rains my car's tach starts idling dropping below 500rpms when I'm at a stop and will cut off if I do not keep my foot on the gas pedal. When I'm driving my exhaust sounds real muffled as if water is clogging the system. I took the car to a person that "specializes" in 300zx maintenance, and he said it was a problem with the fuel injectors. Well I took his advice and changed the fuel injectors, and all was fine until it started raining, then the same problem started happening again. If anyone can help me figure this problem out it will truly be most appreciated.

Sincerely,

I can't drive cause it's rainy outside!

 

do you have splash gaurds? I'm assuming that you have an intake as well....you could be getting water into your engine every time it rains if it rains real hard and splashes a lot of water into your intake. This could be potentially very bad since you can hydrolock your motor. Your MAF sensor could also be getting wet and causing your problems. Check to see if you have splash gaurds under there. FYI, your tach lets you know your RPM level....not your odometer...that's how many miles are on your car...just for future ref.

 

I will check, thanks for the quick response and correction.

 

here's a few shots in the wet dark........

1) When it's rainy, can you get it running and check ecu codes? There might be a clue there.

2) Have you, or can you clean your IACV? A dirty IACV will cause idle problems under normal conditions. Maybe the moisture is compounding an existing problem there.

3) Ditto with any other electrical connection that is not water tight.


Bummer to buy all new injectors and still have a problem.

 

Funny i had the same problem. when it rained i would get moisture in the injector connectors and it would start running rough and then it would be ok opnce it was warm out. i also change 3 of my injectors and cleaned up my connectors and PROBLEMS SOLVED

you might find that if may be difficult to track down some new connectors, but i can take the newer ones from the Z31. There was a recal on those on the Z31 and the new connectors that nissan was selling fit the Z32. You will need to solder the connections on. Your Z speciallist will know what to do with them

 

3rd with the electrical connections. a lot of problems solved because of it