:confused1:i had a weird idle which upon investigation reveled i had a misfire on the drivers side front clynder. ive cleaned the injectior connection, done the screwdriver test, and it was clicking, ohmed the injector which came back with 12.9 i believe this is acceptable? ive also checked that i have a spark swapping the coil packs made no differnce and i pulled the plug and grounded it to the plenum and i got a nice fat spark. the plug itself looked normal no blackness or chunks missing etc. ive cleaned the ptu connections. all im thinking now is taht it could be the injector connector is so badly corroded its past salvage? any advice greatly recived my mot is due this week and im assuming im not gonna be passing with a misfire, due to emmisions.

i think our cars must be twins ! mine was running on 5 again this morning but it was the damm injector plugs again, i really need to cut the f*ckers off and put new ones on

yup agreed, mines having its injector plugs and coil pack connectors renewed soon. had a chat with the guy across the road an old rally entusiast he had a quick look and told me basically clean my connectors better theyre not fully clean and this may have made the issue worse or ittermitent from the removal of the grease and spreading the fillings about etc, ie clean them better it will probally work. the throttle position sensor was the one that he told me off for lol

Have to let me know where you get the connectors from, I also found out that you can buy a new loom from the US about £400 but takes around a day to fit it

Might be a long shot, but my missfire was caused by a water leak under the plenum leaking onto my coilpack and shorting it out. Might be something to check. Just slide a long srewdriver down to your spark plug and see if theres any water on it when you pull it back out.

yeh new loom is summin im more and more tempted with, considering this is sucha common falut im assuming zedworld have/sell replacement connectors so im gonna give them a call tomorrow see it i can get some and maybe new cas and water temp, while im at it those boys look set to cause issues soon.

Apparently a new loom is one of the best things you can spend your money on with these 15-20 year old cars. Can stop lots of little niggles etc by ensuring spot on connections with all sensors etc.

The common thing is to import a LHD loom which fits fine, but has some spare loom that gets tucked under the battery tray and these cost around $375 which is around £230+import duties.

Edited August 2, 201015 yr by turbocraigy

think il save up and get one but time being i think repairing the one ive got is the best option, you would think taht sum 1 out there would produce a non genuine but quality repacement for it, within the uk. (some one out there nudge nudge)

A friend put me on to the loom idea, he said it was a must b4 a real mods and big power. Don't fancy doing it myself tho Its one I'd pay someone else to do

guys hope you can help me, I am new to this whole thing of 300ZX. I bought one last weekend and I am already having problems. Today I drove the car and all was fine, then stoped at a petrol station to pump my tyres, after when I started the car it was not working well at all. It was shaking, it seems like it was working with less cilinders. Do you have any idea what could it be. I went for a drive and got it into high revs and it kind of opened up and it was all ok, but when it went back to low revs it went wrong again. Can you please give me any ideas

first place to start for me would be to pull the coil pack leads off one at a time with the car running, that should give you an idea which one is playing up.

now you have to work out if its fuel or elec problem, the quickest way is to take a LONG screw driver and put one end on top of the plate that holds the injectors in and the handle end to your ear. you should hear a loudish clicking which is it firing (check them all)

still no joy?

next is to take the coil packs out check the plugs, if all is fine put the plugs back ang get a spare plug put it in the end of the coil pack and ground the plug and check for a spark. goes without saying its done with the engine running and one at a time !

still no joy???

check the ptu the connectors maybe shittty and look for split wires.

still no joy?????

check the ECU for fault code (look on the forum theirs a few post) its easy so dont worry

but it my just show code 21 which aint much help.

try that for now mate and let us know how it goes

P.s watch out for the fan while your under the bonnet with it running,the bitch will cut your fingers off !!!!

guys hope you can help me, I am new to this whole thing of 300ZX. I bought one last weekend and I am already having problems. Today I drove the car and all was fine, then stoped at a petrol station to pump my tyres, after when I started the car it was not working well at all. It was shaking, it seems like it was working with less cilinders. Do you have any idea what could it be. I went for a drive and got it into high revs and it kind of opened up and it was all ok, but when it went back to low revs it went wrong again. Can you please give me any ideas

Ok, thanks for the tips. as i didnt have time to do all this tonight all I did was left the car for a good 3 hours of rest. I have just been outside and started it up and it was all ok. I took it for a quick spin and it seemed to be running smooth until I put my foot on the gas a little further. It all went bad again. Do you know how it will fix it self automaticly and then just mess up again?

Ok, thanks for the tips. as i didnt have time to do all this tonight all I did was left the car for a good 3 hours of rest. I have just been outside and started it up and it was all ok. I took it for a quick spin and it seemed to be running smooth until I put my foot on the gas a little further. It all went bad again. Do you know how it will fix it self automaticly and then just mess up again?

 

Things like this are very difficult to pin point because they can be from many causes.

The PTU on these cars is a common weak point and can cause the car to cut out or run lumpy when failing - this tends to happen with heat and then later after a cool down they are ok again for a while.

It could also be bad connections to coil packs or injectors. The looms on these cars get brittle and/or gunked up with green corrosion. Remember the engine moves slightly under varying loads and this can effect these connections if poor.

You need to learn quickly, use the search function to help - there is years of help & advice.

Ultimately though if you've just got it I would booked it in to a specialist for a health check whilst you learn more and more....

Yes, I will probably book it in for a specialist to check it out as I dont even know what a PTU is. I dont want to start taking things off and then not being able to put them back together. Like you said I will have to learn quick, but hopefully I would not need do much on the car it self.

Thanks for the tip and will let you know how thing get on, if you are interested.

code 21 is ptu mine had same problem iall have aspare changed ptu now fine

PTU is the Power Transister Unit, Look at the Left side of Cam Cover its the Square thing fixed underneath that big connector.

 

It is a Series 1 which were prone to overheating which cause electricity to spark plugs and coilpacks to be unstable.

 

Car Never had any previous issues before hand with it. When your issues Started (bobo_999) was it a Hot Day???

Yes, I will probably book it in for a specialist to check it out as I dont even know what a PTU is. I dont want to start taking things off and then not being able to put them back together. Like you said I will have to learn quick, but hopefully I would not need do much on the car it self.

Thanks for the tip and will let you know how thing get on, if you are interested.

 

Wish I could help you more, but unfortunately London is rather far way from me to have a look!

Please do let us know how you get on and what the solution was because its very helpful for future Zedders that may have similar issues and use this site for help & advice. All too often people forget to add the conclusion to threads.

Best of luck:):duffer:

pretty sure mine is caused by injector connectors being fubar, need replacing the shake dislodge loose signal so i loose cylnders and gain them etc. its booked in on the 16th with a specialist just to get it done sick of faffing baout with it. bobbo999 welcome to zed ownership was in the same place as yourself last year

They are worth it tho :)

car is going in tomorrow hopefully find out whats up. bobbo999 did you sort your running issues?