so confused
09-13-2010 | 11:18 AM
#1
Thread Starter
Registered User
Joined: Sep 2010
Posts: 5
so confused
so i just bought a 1990 300zx 2x0 and its really tricky to start you have to put the clutch into like a sweet spot sort of thing to start it and then once you start driving it dosent like to go into second but once its in its fine and when you push the clutch all the way in to stop at a light the rpms just go down and the car dies...
any ides on what the problems are?
any ides on what the problems are?
09-13-2010 | 11:34 AM
#2
Registered User
Joined: Sep 2008
Posts: 283
From: Collingswood, NJ
if the car doesn't die when it's in neutral my first guess would be the clutch isn't completely disengaging.
I would check the fluid and try to bleed it.
Also, does it crank when you try to start or does it act like the clutch safety switch is cutting off the start?
I would check the fluid and try to bleed it.
Also, does it crank when you try to start or does it act like the clutch safety switch is cutting off the start?
09-13-2010 | 09:40 PM
#3
Thread Starter
Registered User
Joined: Sep 2010
Posts: 5
i found out today that the clutch pedal wasnt actally hitting the starter switch fully so i fixed the starting problem but then i replaced the spark pugs and now it wont start at all it cranks but nothing unless you give it gas and hold the gas at like 1000rpm but it sounds really bad so idk i think clutch fan is shot so im guna replace that and hopefully it helps but idk
09-14-2010 | 10:23 AM
#4
Encyclopedic Knowledge
Joined: Aug 2005
Posts: 3,316
From: Naperville, IL
The clutch fan will never cause your car to run like poorly unless it's overheating. lol
Did you use NGK spark plugs? If you didn't, that's your problem. You cannot use other spark plugs on the 300ZX.
Did you use NGK spark plugs? If you didn't, that's your problem. You cannot use other spark plugs on the 300ZX.
09-14-2010 | 02:43 PM
#5
Registered User
Joined: Jun 2009
Posts: 94
From: ElDorado Springs, MO
Wasted you should go through and clean all your electrical connections then put them back together with some dielectric grease. PTU, CAS, TPS, coil pack & injector connectors would be a good place to start. Unhook the battery first.
09-14-2010 | 02:45 PM
#6
Encyclopedic Knowledge
Joined: Aug 2005
Posts: 3,316
From: Naperville, IL
Working is not the same as working right.
https://www.zdriver.com/forums/showp...0&postcount=19
https://www.zdriver.com/forums/showp...0&postcount=19
If you haven't changed the plugs in your NA yet, I'd bet you don't know what the inside of the cylinder head looks like, either. In which case, of course you wouldn't understand why we recommend ONLY NGK plugs. It's not because Nissan says so. So let's look at the VG30DE[TT] cylinder head design.
Notice that the hole where the spark plug enters the combustion chamber is raised a bit. Now let's look at some spark plugs...
Notice that the ONLY spark plug with a design to overcome this lip in the cylinder head is the NGK plug. The other two plugs would not even extend into the combustion chamber! They'd be firing from inside the recess of the lip. Furthermore, the closer to the center of the combustion chamber the plug gets, the more evenly it burns the air/fuel mixture. No multi-electrode design will be able to overcome the extra length into the cylinder that the NGK plugs get. The VG30DE[TT] cylinder heads are simply designed in such a way that they do not function as well with other plugs.
Next time you think you're smarter than Nissan engineers, remember... you're not.
Notice that the hole where the spark plug enters the combustion chamber is raised a bit. Now let's look at some spark plugs...
Notice that the ONLY spark plug with a design to overcome this lip in the cylinder head is the NGK plug. The other two plugs would not even extend into the combustion chamber! They'd be firing from inside the recess of the lip. Furthermore, the closer to the center of the combustion chamber the plug gets, the more evenly it burns the air/fuel mixture. No multi-electrode design will be able to overcome the extra length into the cylinder that the NGK plugs get. The VG30DE[TT] cylinder heads are simply designed in such a way that they do not function as well with other plugs.
Next time you think you're smarter than Nissan engineers, remember... you're not.
Last edited by ZLover4Life; 09-14-2010 at 05:38 PM.
09-14-2010 | 03:06 PM
#7
Registered User
Joined: Jun 2009
Posts: 94
From: ElDorado Springs, MO
Yeah I've seen you spark plug pic before but I still don't see an Autolite in the lineup. The business end of an Autolite APP3923 and a NGK PFR6G-11 are the same length.
What NGK plug do you have in the pic? If it's a PFR6B-11B then they were only for the TTZs anyway.
Either way I have a pair of NA heads on the bench and the Autolite and NGK plugs both extend out into the combustion chamber just fine. I usually only use NGK plugs but couldn't find the proper ones for the Z locally so I got the Autolites at Wal-mart. After finding out the the NGKs were about $7 each higher I decided to leave the Autolites in there where they have been for 40k miles.
What NGK plug do you have in the pic? If it's a PFR6B-11B then they were only for the TTZs anyway.
Either way I have a pair of NA heads on the bench and the Autolite and NGK plugs both extend out into the combustion chamber just fine. I usually only use NGK plugs but couldn't find the proper ones for the Z locally so I got the Autolites at Wal-mart. After finding out the the NGKs were about $7 each higher I decided to leave the Autolites in there where they have been for 40k miles.
Last edited by xpwarrior; 09-14-2010 at 04:03 PM.
09-14-2010 | 06:14 PM
#8
Encyclopedic Knowledge
Joined: Aug 2005
Posts: 3,316
From: Naperville, IL
Just be honest with yourself - you put crappy plugs in your car. That's also largely why they were $7 less per plug. LOL (Price is set by cost and demand... there is no demand for **** parts, and good parts cost more to make.)
09-14-2010 | 06:56 PM
#9
Registered User
Joined: Jun 2009
Posts: 94
From: ElDorado Springs, MO
That's because Autolite is garbage and doesn't belong in a lineup with NGK, Bosch, and HKS. You wouldn't see Z32 owners comparing Nissan or Mobil1 oil filters to Fram, either. (Autolite and Fram are of the same company...)
Just be honest with yourself - you put crappy plugs in your car. That's also largely why they were $7 less per plug. LOL (Price is set by cost and demand... there is no demand for **** parts, and good parts cost more to make.)
Just be honest with yourself - you put crappy plugs in your car. That's also largely why they were $7 less per plug. LOL (Price is set by cost and demand... there is no demand for **** parts, and good parts cost more to make.)
Anyway I thought the whole point of your pictures was to point out that the plugs were too short but that only applies to a TTZ. The NAs don't have to have the extended tip.
I am honest with myself. I am sure that from your point of view I have built my car from all kinds of crap parts including Ebay headers, Ebay clutch PP and flywheel. I did splurge and get a Z1 single piece driveshaft when I went 5-speed but you hate those to due to the dreaded increase in NVH.
Crap parts or not the cars runs extremely well and does everything I want it to do. I would sure hate to be the guy that spends all kinds of money on every top of the line part to build his car and then have something simple happen like a blown head gasket and end up having to part the car out because he couldn't afford to fix it.
09-14-2010 | 07:30 PM
#11
Registered User
Joined: Jun 2009
Posts: 94
From: ElDorado Springs, MO
I pulled the upper plenum on mine to remove the water lines and it would not run at all when I put it back together. Had to go in and clean the injector and coil pack connectors. Just taking them off and on was enough to totally screw up the connections. I had like one injector and two coils firing and it was running great before.
You can also check the trouble codes in case the ECU knows what the problem is.
Last edited by xpwarrior; 09-14-2010 at 07:47 PM.
09-15-2010 | 05:42 AM
#13
Registered User
Joined: Jun 2009
Posts: 94
From: ElDorado Springs, MO
I never said that the NA heads don't have a lip. The deal is that the TT and NA Zs use different plugs. The TTZs need the longer plug with the extension that you have pictured and the NA takes the shorter plug. PFR6B-11B for TT and PFR6G-11 for NA and the PFR6G-11 is the same length as the Autolite and judging from your pictures the same length as your Bosch and HKS.
I do have pics of the shorter plugs in the NA head and will post when I get time. They don't stick out as far as a TT plug would but the electrode is in no way recessed in the head.
I do have pics of the shorter plugs in the NA head and will post when I get time. They don't stick out as far as a TT plug would but the electrode is in no way recessed in the head.
09-15-2010 | 07:55 PM
#15
Registered User
Joined: Jun 2009
Posts: 94
From: ElDorado Springs, MO
My owners manual and my Z say different. Did you read the last line in Zlovers spark plug picture post about being smarter than a Nissan engineer? I guess you must be.
Wait aren't you the one that stuffed a new style injector in an old style rail without an adapter then couldn't figure out why the cylinder was full of gas and wouldn't crank over?
Wait aren't you the one that stuffed a new style injector in an old style rail without an adapter then couldn't figure out why the cylinder was full of gas and wouldn't crank over?
09-15-2010 | 08:50 PM
#16
Ruff Ryder
Joined: Sep 2005
Posts: 6,140
From: palm desert
My owners manual and my Z say different. Did you read the last line in Zlovers spark plug picture post about being smarter than a Nissan engineer? I guess you must be.
Wait aren't you the one that stuffed a new style injector in an old style rail without an adapter then couldn't figure out why the cylinder was full of gas and wouldn't crank over?
Wait aren't you the one that stuffed a new style injector in an old style rail without an adapter then couldn't figure out why the cylinder was full of gas and wouldn't crank over?
09-16-2010 | 04:03 PM
#17
Thread Starter
Registered User
Joined: Sep 2010
Posts: 5
alright so i got it running and it runs...ok... not great and theres a nasty like metal on metal knock coming from the back of the engine on the passenger side. and it still dies when you push the clutch in anyone have any idea what the problem is now?
09-16-2010 | 04:50 PM
#18
Encyclopedic Knowledge
Joined: Aug 2005
Posts: 3,316
From: Naperville, IL
There's a general rule when asking for help on a forum - you can't provide too much information. You got it running HOW?
How frequent is the knock? I assume it varies with rpm?
And does it die if you push the clutch in while revving a little?
These are all things that should've been detailed in that last reply...
How frequent is the knock? I assume it varies with rpm?
And does it die if you push the clutch in while revving a little?
These are all things that should've been detailed in that last reply...
09-16-2010 | 06:48 PM
#19
Tough Guy
Joined: Nov 2003
Posts: 851
From: NJ
My owners manual and my Z say different. Did you read the last line in Zlovers spark plug picture post about being smarter than a Nissan engineer? I guess you must be.
Wait aren't you the one that stuffed a new style injector in an old style rail without an adapter then couldn't figure out why the cylinder was full of gas and wouldn't crank over?
Wait aren't you the one that stuffed a new style injector in an old style rail without an adapter then couldn't figure out why the cylinder was full of gas and wouldn't crank over?
I learned from my mistake, now learn from yours.
09-16-2010 | 07:10 PM
#20
Registered User
Joined: Jun 2009
Posts: 94
From: ElDorado Springs, MO
Sorry that was mean of me.
Hoov thanks for posting the pics and saving me the time. I understand why people think the longer plug is better but with the short plug the flame kernel is still totally exposed to the combustion chamber except for the area of the ground electrode. The NA came before the TT and Nissan designed the ridge around the plug and chose the shorter plug. From what I understand the extended plug was designed for the TT to fix a detonation problem under boost not as a performance improvement.
If someone has dyno numbers proving the extended plug is better in a NA then I will whip out my CC and order a set.
Rockchucker is making 222rwhp on his NA and he is using the short NGK iridiums.
If it makes you feel warm and fuzzy to use the extended plug in a NA then go for it. I just don't think it's right to tell a new guy that he has to use the extended plug or his NA won't run right.
Wasted did you ever check for trouble codes?
Hoov thanks for posting the pics and saving me the time. I understand why people think the longer plug is better but with the short plug the flame kernel is still totally exposed to the combustion chamber except for the area of the ground electrode. The NA came before the TT and Nissan designed the ridge around the plug and chose the shorter plug. From what I understand the extended plug was designed for the TT to fix a detonation problem under boost not as a performance improvement.
If someone has dyno numbers proving the extended plug is better in a NA then I will whip out my CC and order a set.
Rockchucker is making 222rwhp on his NA and he is using the short NGK iridiums.
If it makes you feel warm and fuzzy to use the extended plug in a NA then go for it. I just don't think it's right to tell a new guy that he has to use the extended plug or his NA won't run right.
Wasted did you ever check for trouble codes?
09-16-2010 | 07:19 PM
#21
Ruff Ryder
Joined: Sep 2005
Posts: 6,140
From: palm desert
Sorry that was mean of me.
Hoov thanks for posting the pics and saving me the time. I understand why people think the longer plug is better but with the short plug the flame kernel is still totally exposed to the combustion chamber except for the area of the ground electrode. The NA came before the TT and Nissan designed the ridge around the plug and chose the shorter plug. From what I understand the extended plug was designed for the TT to fix a detonation problem under boost not as a performance improvement.
If someone has dyno numbers proving the extended plug is better in a NA then I will whip out my CC and order a set.
Rockchucker is making 222rwhp on his NA and he is using the short NGK iridiums.
If it makes you feel warm and fuzzy to use the extended plug in a NA then go for it. I just don't think it's right to tell a new guy that he has to use the extended plug or his NA won't run right.
Wasted did you ever check for trouble codes?
Hoov thanks for posting the pics and saving me the time. I understand why people think the longer plug is better but with the short plug the flame kernel is still totally exposed to the combustion chamber except for the area of the ground electrode. The NA came before the TT and Nissan designed the ridge around the plug and chose the shorter plug. From what I understand the extended plug was designed for the TT to fix a detonation problem under boost not as a performance improvement.
If someone has dyno numbers proving the extended plug is better in a NA then I will whip out my CC and order a set.
Rockchucker is making 222rwhp on his NA and he is using the short NGK iridiums.
If it makes you feel warm and fuzzy to use the extended plug in a NA then go for it. I just don't think it's right to tell a new guy that he has to use the extended plug or his NA won't run right.
Wasted did you ever check for trouble codes?
09-16-2010 | 07:38 PM
#23
Registered User
Joined: Jun 2009
Posts: 94
From: ElDorado Springs, MO
According to Wiki the MID4 used a VG30DE and came out in 85. The MID4 II came out in 87 with the VG30DETT.
What do you think the extended tip does to the plug temp? I've read both ways that it makes it colder and hotter. Does the extended tip actually poke out into the combustion chamber? I would think that would make the end hotter but if the purpose was to help with detonation you would think it should be colder.
What do you think the extended tip does to the plug temp? I've read both ways that it makes it colder and hotter. Does the extended tip actually poke out into the combustion chamber? I would think that would make the end hotter but if the purpose was to help with detonation you would think it should be colder.
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