I have a 84 z31 turbo new plugs,ngk wires, cap, rotor,new 02,new chts w/ subharness. Runs great cold bogs on acceleration when hot until boost kicks in, if i disconnect the CHTS it runs great but i get no boost. WTF?

 

Welcome to ZDriver!

Pull the ecu codes. You will probably have an extra code now that you've run it w/ the CHTS disconnected.

 

chts should have nothing to do with the boost. Your turbo works or it doesn't. replace chts probably do away with your problem. cheap fairly easy to do. search there is a write up on the web. if using stock boost gage better to get a mechanical one. harbor Freight $20. I don't put a lot of faith in the ecu codes. my experience they don't often lead to the problem.

 

Just got the codes had 3 in system - 23,24 and 31. I had disconnected the battery for the weekend reconnected then drove it for a while interestingly enough for some reason when i put ecu into test mode car ran even worse for first 4 blocks

 

That was one of the first things i replaced with sub harness

 

As mentioned before had codes 23,24,31 reset codes went for another drive and now i have 12,13,31 Any ideas? could the MAF cause the bad idling and bogging at operating temp? Oh it also dies when coming to a stop from speeds.

 

How did you "reset" the codes? Disconnect the battery?

Was it doing the same thing as always when you got the new codes on the second time?

Sounds to me like a wiring problem. Have you checked the ecu connections? Do you have the a/c removed or disconnected? Have you checked the alternator for proper output levels?

 

I replaced the MAF yesterday running better, however at operating temperature slow as hell getting off the line as it approaches 2600 rpm or so it starts to haul. Runs great at RPM's greater than 2600. When coming to a stop it dies every time but only at operating temperature. Tried to adjust the Idle so i disconnected the AAC she barely runs then, I then adjusted the screw in and out with no change in Idle. Timing is set at 20 degrees. Just to reiterate new MAF, Alternator, battery, belts, CHTS w/harness, O2 sensor. Codes had been reset by disconnecting the battery. Any help would be greatly appreciated!! the car has 70k on it and this was the 1st O2 sensor could the "off the line" issue be a fuel mixture problem? oh, the A/C is disconnected explaining the 31 code. Probably unrelated by i noticed that the rubber stopper for the neutral safety switch is missing on the clutch pedal. I also disconnected the ECU and re inserted connectors. The only code now is 31

 

I replaced the MAF yesterday running better, however at operating temperature slow as hell getting off the line as it approaches 2600 rpm or so it starts to haul. Runs great at RPM's greater than 2600. When coming to a stop it dies every time but only at operating temperature. Tried to adjust the Idle so i disconnected the AAC she barely runs then, I then adjusted the screw in and out with no change in Idle. Timing is set at 20 degrees. Just to reiterate new MAF, Alternator, battery, belts, CHTS w/harness, O2 sensor. Codes had been reset by disconnecting the battery. Any help would be greatly appreciated!! the car has 70k on it and this was the 1st O2 sensor could the "off the line" issue be a fuel mixture problem? oh, the A/C is disconnected explaining the 31 code. Probably unrelated by i noticed that the rubber stopper for the neutral safety switch is missing on the clutch pedal. I also disconnected the ECU and re inserted connectors. The only code now is 31

 

1984 300zx single turbo at operating temperature she is slow as hell getting off the line as it approaches 2600 rpm or so it starts to haul. Runs great at RPM's greater than 2600. Tried to adjust the Idle so i disconnected the AAC she barely runs then, I then adjusted the screw in and out with no change in Idle. Timing is set at 20 degrees. has new MAF, Alternator, battery, belts, CHTS w/harness, O2 sensor. Codes had been reset by disconnecting the battery it no longer has any codes in the ECU. Any help would be greatly appreciated!! the car has 70k on it and this was the 1st O2 sensor. could the "off the line" issue be a fuel mixture problem? I also disconnected the ECU and re inserted connectors.

 

Check your injectors maybe?

Its been a long time since I did anything on a z31 but i know on my z32 with a bad injector, once it gets to around 3000 rpm it will balance itself out and move like its supposed to.

Keep in mind with the injectors, theres a recall on all z31s, nissan will replace the injectors for free.

Also maybe look for vacuum leaks?

 

check for vacuum leaks, test the coil, test the MAF, try a hotter plug, OHM the injectors...etc

 

It's not a recall. And if you ask the dealership about it, they'll give you the "You're stupid" look and send you on your way.

It's also been reported that the kits to do the "FUEL INJECTOR SAFETY CAMPAIGN" are no longer available.

 

Sorry for this but ...... Grenada Nissan in Mississippi replaced mine 4 Months ago..and im pretty sure theyll replace them again... There is also a place in Memphis,TN that will place injectors on ALL 84+ Z Cars for free....Two weeks ago one of our members got a set of injectors dropped in down in Jackson,MS....so why shouldnt they be doing it everywhere else?....idk

 

Like I said, it's been reported. A couple people in another area haven't been able to get it done. Their dealership told them the parts were no longer available. I haven't had any experience with it since all my cars were done over a decade ago.

 

I dont want to burst your bubble either, but you dont know what youre talking about.

Ive had the injectors replaced in three z31s over the past 5 years.

If they look at you like youre stupid, tell them to do their ****ing jobs.

 

Also saying that if one dealer says it's NLA, most of the time someone somewhere has one. If I can find a brand new front frame for a 73 camaro at a dealer when it's supposedly NLA, chances are you can find an injector service kit. and if the tech doesn't want to do his job, call his supervisor. it's exactly like the flunkies at autozone, pepboys, kragen..etc they say they don't have it, can't get it's discontinued and then you go on there computer and it says they have one in stock, or the store across town has one.

 

And when was the last one you had done? The campaign is over 15 years old now.

Like I said. I've never had a problem, but I haven't had to have it done in a decade. So this is what I was told on another message board.

http://www.z31performance.com/forum/...p?f=14&t=18876

 

Great diatribe! however what does a bad injector have to do with the stated issue? If you disconnect the CHTS the car runs like a champ if you disconnect the CHTS when the engine is cold it will not start, when warm i disconnect the CHTS and the car runs fantastic but the emissions are off the chart. A bad injector is a bad injector not a sometimes problem. Since the last post I have ohmed out the power transistor and according to the Chiltons manual it doesnt have continuity where it should. So i will be ordering one today. With any luck that will resolve the problem.

 

Have you had any Power Transistor issues? could that be my issue with no pick up with CHTS connected ? as outlined in earlier post

 

Still having the same problem runs great cold when gets to operating temp its like some one thru a switch and the car can not get going from a stand still, accelerates real slow until it hits about 2800 rpm then the boost kicks in and it takes off. It stalls at almost every stop when hot also. No codes in ecu produces code 44 when running diagnostic so the ecu should be good. I just replaced the brand new CHTS that was aftermarket with another brand new one from Nissan with no change (i have the proper voltages at the Pj on the ECU for the CHTS ). Any suggestions other than lighting it on fire!!!!!!!!!(new maf,new 02,plugs,wires, cap,rotor,fuel filter, ignition control module,battery,alternator,timing at 20 degrees.

 

Still having the same problem runs great cold when gets to operating temp its like some one thru a switch and the car can not get going from a stand still, accelerates real slow until it hits about 2800 rpm then the boost kicks in and it takes off. It stalls at almost every stop when hot also. No codes in ecu produces code 44 when running diagnostic so the ecu should be good. I just replaced the brand new CHTS that was aftermarket with another brand new one from Nissan with no change (i have the proper voltages at the Pj on the ECU for the CHTS ). Any suggestions other than lighting it on fire!!!!!!!!!(new maf,new 02,plugs,wires, cap,rotor,fuel filter, ignition control module,battery,alternator,timing at 20 degrees.

 

Merged all 3 threads.

Please don't make a new thread every time you log in. Continue the discussion of the same issue on the same thread so we don't have to start over every time.

 

While it's running, pull the vacuum hose off the fuel pressure regulator. See what happens.

 

Removed the vacccum hose, no change still slow as hell getting up to boost point. At idle the engine runs smooth pulled the vacuum hose and no change there either.