Just bought an 88 300zx M/T N/A. I drove it home but it has very little power. My 3 cyl metro has more power. The engine sounds fine, no chatter or anything of the like. It idles fine too. If revved it backfires. I changed plugs, wires, cap, and rotor, but no change. any ideas?

 

Most likely a timing issue then, get a timing light and check.

 

Welcome to ZDriver!

I DD a 94 Geo Metro.

Like Skully said, check timing. Also check ecu diagnostic codes.

 

Checked codes. The ECU threw 13 and 42. Fuel temp sensor and cylinder head temp sensor. Im gonna just replace the chts but I cant find anything on the fuel temp sensor. I just called the local Nissan dealership and they didnt either. I'm still gonna check the timing on my next off day. Hopefully I'll make a breakthrough.

 

timing is fine. the engine seems fine running at idle but struggles in gear.

 

Awesome, did you replace the sensors yet?

 

nope. cant find them.

 

Motorsport! Temperature Sensor, Cylinder Head, 84-89 300ZX - The Z Store! Nissan-Datsun 240Z-260Z-280Z-280ZX-300ZX(Z31/Z32)-350Z-370Z Parts

https://conceptzperformance.com/Cart...ion.php?II=591 <--- its the same unit for z31's, same part #.

I guess to edit, sensors do go bad, but sometimes the wiring is in worse shape than the sensor, check the connections clean them, etc.

 

Whoever worked on the car before me did a bang-up job on the wiring, so I'm gonna have to go through all that anyway, so I'll be sure to check all that. I've done some more research and I think I'm gonna replace the ignition coil and see if that helps. I'm to the point where I expect something new every time I pop the hood. I mean, the headlights are spliced together (poorly), the EGR line has a hole that's patched with a hose clamp with a piece of a diet coke can, the airflow adjustment screw was closed, and the cat is busted hollow. What next? lol

 

By the way, Skully. Thanks a billion for the links!

 

You got the factory service manual at XenonZ31 Reference right? It's a freebie DL. Other docs there too. Check'em out.

Don't worry about your Z. You will get it running. You're just filling in for the regular maintenance previous owners didn't give it. Z31s are magic.

 

Yeah. Its a solid machine. Like you said, I just have to make up for all the neglect. Its gonna be killer when I'm done. I'm more of a body guy, so once I get it operating correctly I can really get into it. Ive always wanted a Z and this is my first, so its gonna be my baby.

 

Yep! That's the Z. How about a pic under the hood? Thanks.

 

best 300 bucks i ever spent.

 

Looks really good!! Awesome!

 

Got the FSM. Very useful. Thanks for the link. I'll take some pics under the hood tomorrow. Busy as hell. lol

 

Well, I replaced the coil and it went from 20-30% power to maybe 50-60%... Still havent checked the sensors. Maybe that'll be it.

 

Yep, the sensors are notorious on Z31s. CHTS especially. I would use my multimeter to check the 2 solenoids on the air regulator too.

The wiring? After 26 years, connectors get corroded and grimy, will just disconnect on their own one day and make you crazy. When you get the time, go through all your harness connections in the engine bay and disconnect them, spray/squirt clean them and reconnect. That baby wants to run right! You will see. It's a Z31

 

By the way, guys... I recently found the issue... 3 bad injectors... Yeah 3. I feel like an idiot. lol