z32 #6 cylinder problem

[enduro80]

hello all ok so im having a problem with my 6th cylinder not firing.checked coil pack,fine..spark,fine...compression,fine...got injector from pep boys,put in car ran great for 10 min.then lost spark.then started later inthe day nowthecar wasnt firing on #6 injector again..then got a nissan injector for it ,put in and car still not firing on that cylinder...we had cleaned all connectors,tested spark plugs..have no idea whats the problem dont know what to do besides send it to nissan?

PLEASE HELP,THANKS

[Ziggy1621]

Have you run the ecu self diag on it?

[enduro80]

ziggy1621 no i did not i actually dont know how..could you help me with that and explain how to do it?

[t.mcginley.jr]

http://www.nicoclub.com/archives/nissan ... ostic.html

If the injector and coil pack are fine then you have an issue before that, either the CAS or PTU. You can check the CAS by removing it from the front of the engine (3 bolts), leave the connector on it and turn it by hand. You should hear each injector click as you rotate it. The easiest way to check the PTU is getting a known good one and swapping it in, it's just two connectors. They sell used ones on ebay and they interchange with a number of other nissan models.

[Ziggy1621]

Would the cas or ptu be making only one cylinder miss?

[t.mcginley.jr]

Normally I think it makes multiple cylinders miss and causes a general rough idle, but if one pin happens to be messed up on a connector it could be causing one dead wire, which would cause one dead cylinder. He will know more when he runs the ecu diagnostic tho

[enduro80]

awesome thanks guys im going to run those tests once i can .hopefully will be posting back with good news...also if i do have a bad ecu how costly of a fix is it to buy a new one

[t.mcginley.jr]

I don't think I've ever heard of someone fixing an ecu, but you can buy used ones on here (classifieds section or classifieds on twinturbo.net) or on ebay. Usually they are $100-150 I think

[enduro80]

hey guys okay..so i did the test and seem to be throwing codes 21: ignition signal circuit ,and 34: detonation sensor circuit..so what does this mean and how can i fix it...also started car today and now cylinder #6 and #5 are not firing ..

[Ziggy1621]

Well code 21 is fixed by a new PTU and/or new ptu harness harness. The detonation sensor can be bypassed just for testing purposes. If that clears it, then replace it with an OEM one.

PTU http://www.z1motorsports.com/product_in ... ts_id=4181
Ptu harness http://www.z1motorsports.com/product_in ... ts_id=1776

Knock bypass for testing http://www.z1motorsports.com/product_in ... ts_id=5580 (again, I wouldn't leave this in, just for testing)

Knock sensor http://www.z1motorsports.com/product_in ... ts_id=1727

[enduro80]

!!well thankyou both very much! my car is running great! seem some dumbass that looked at the car before but dielectric grease on the ptu harness causing it to conduct wrong and mess up.. cleaned that out and no longer a code #21 and all cylinders running now .. but seem the code #34 was right and the knock sensor is bad. saw that after i ran that bypass and then no codes.. so all i have to do is order that knock sensor but i assume i can still drive it?? till the part gets here ... again i thank you guys so much!

[enduro80]

also! if i ran the car with a resistor in it like in the bypass test till the part got here.how bad would that be? could it cause damage to my z?

[Ziggy1621]

just don't drive it like ou stole it until after the part is in of course Glad you got it worked out!

[enduro80]

hahah well ill try ...other little things.. oil pressure starts at 0 and goes up as i drive and fuel gauge always says full.. any known issues with that?

[Ziggy1621]

Does the oil pressure level off at a safe level? If so, I'd say replace the gauges

[enduro80]

@ Ziggy1621 ,At an idle it stays at -0-. As soon as you step on the gas it climbs just as the Tachometer does .Just wondering if I should go with a sending unit .Strange that it drops out during idle .I'm not getting any top end noise or anything so I doubt it' s an oil pressure issue , but then again who knows .Again thanks a ton . You guys have been a world of help ..

[Ziggy1621]

No prob! Maybe one of the other guys can chime in as to what goes out more frequently.