Hi guys what are the benefits of having an S1 PTU?

S1 prone to failure in later years, S2 was re-design by Mr Nissan on later zeds as far as I'm aware

What does a PTU control/do?

Isn't it ignition timing or something equally as black magic like?

In fact, there you go matey

 

 

http://wiki.answers.com/Q/PTU_1990_300zx

Power Transistor Unit it ups the voltage to each of the coils for spark timing and power

PTUs are basically six power transistors in a box. They provide the interface between the ECU and coils to handle the higher current (amps) load required by the

coils to work. S1 units suffered from internal connection failures on the circuit board which Nissan overcame with the S2 units. You can read more here on S1 units and repair:

 

http://www.pexcom.com.au/z32cms/e107_plugins/content/content.php?content.270

 

-Andrew

Isn't it ignition timing or something equally as black magic like?

 

lol... what he said....

very informative thank you very much, mine starts and runs fine anyway of telling if its had the upgrade or not do we know???

Yup! simply look at it, if it's Grey alloy colour with what looks like fins it is series 1, if it's Black and hard plastic, it's series 2.

Smithy

Thing is thoughi know everyone gets excited and blames ol series one, but how many zeds are there driving around on 20 plus year old series 1s with no falut to the unit? Yes they can fail but look at it differently are you really suprised after playing with thevrest of the engine loom those years havent taken thier toll.

Totally in agreement with you Stephen. My 1990 z had a series one ptu on it for 26 years and was only changed because I had a series 2 in a box of spares and just figured it would be an upgrade and may make the car run more stable.

The said series 1 ptu is still in good working order and has been kept as a spare ready for when the good old series 2 gives up..

I understand that the series 2 has a higher load capability and can make the engine slightly smoother or responsive but from the change of mine I've noticed no difference that's recognisable.

I say if it ain't broke, leave it the heck alone! You find it stays working longer then! If your series one goes breasts skywards then either replace it with a series one again cheaply or spend a few quid and get a series two loom connector and a series 2 ptu.. Either one you put on the car will probably make no difference to the way it drives or runs.. So in my honest opinion, I'd rather have the cool looking heatsink rather than the boring old plastic box..

Hide the boring old box, don't forget, if you're getting a new Wiring Specialties Loom, they only connect to the later series 2 PTU:thumbup1:

I understand that the series 2 has a higher load capability and can make the engine slightly smoother or responsive but from the change of mine I've noticed no difference that's recognisable.

 

A golden oldie thread! I'm not suprised you noticed no difference. Series 1 - six power transistors in a box, Series 2 - six power transistors in a box.

A golden oldie thread! I'm not suprised you noticed no difference. Series 1 - six power transistors in a box, Series 2 - six power transistors in a box.

 

Yup.. Only difference really is the series 2 has no heatsink.. If that's not a downgrade, I'm not sure what is.. :lol:

"I'm livin' in a box, I'm livin' in a plastic box"

Yup.. Only difference really is the series 2 has no heatsink.. If that's not a downgrade, I'm not sure what is.. :lol:

 

Yes it does. If you flip the S2 PTU over you will see a metal plate. That and the mounting bracket forms the heatsink.

So can somebody tell us IF series 1 have inferior design and prone to fail MORE SO than the S2.

Most places say series 1 are prone to internal connection failure, perhaps because of heat or because they are fragile.

I know they do the same thing but are the internals the same.

 

I'm not trying to claim that S1 always break, but if there is some truth to the myth.

 

My series 1 had internal connection failure so in a way that convinced me (as well as reading stuff inline and being told by people) that they were an inferior design and the problem doesn't happen with s2s.

Edited September 16, 20169 yr by Alic

so whats the talk then about 1 v 2 ptu and over heating why did nissan change it on later cars ? did it really over heat. if its the same bit with no heat sink is there a chance the heat sink never worked as they planned and removing it stopped it over heating just an idea. seems every one one here just repeats what other tell them whats the facts and who had done any tests on this issue,

so whats the talk then about 1 v 2 ptu and over heating why did nissan change it on later cars ? did it really over heat. if its the same bit with no heat sink is there a chance the heat sink never worked as they planned and removing it stopped it over heating just an idea. seems every one one here just repeats what other tell them whats the facts and who had done any tests on this issue,

 

All I can say Dan, is I've had a factory installed series 1 ptu on my car that hadn't failed in 26 years.. I know of people who's series 2 have failed and also series one. I think the secret to keeping the series one going is relocation away from heat sources like under the nose panel but at the end of the day, I don't see that a series one or two have any difference in functionality. They both work and as far as I'm aware, the series 2 is the same module just with better quality wiring that gives a higher and more stable voltage capacity.. Since changing to S2 I haven't noticed any difference in the cars running at all..

So reliability being an issue on series 1 I don't believe to be an issue.. Its simply age related in my opinion and experience aswell as the care taken if the unit and its connections. Like any electrical device, it can and will fail over time but the better it's cared for, the longer it might last..

All I can say Dan, is I've had a factory installed series 1 ptu on my car that hadn't failed in 26 years.. I know of people who's series 2 have failed and also series one. I think the secret to keeping the series one going is relocation away from heat sources like under the nose panel but at the end of the day, I don't see that a series one or two have any difference in functionality. They both work and as far as I'm aware, the series 2 is the same module just with better quality wiring that gives a higher and more stable voltage capacity.. Since changing to S2 I haven't noticed any difference in the cars running at all..

So reliability being an issue on series 1 I don't believe to be an issue.. Its simply age related in my opinion and experience aswell as the care taken if the unit and its connections. Like any electrical device, it can and will fail over time but the better it's cared for, the longer it might last..

 

 

There is no intended performance or difference in running intended with a S2 PTU. It is purely for reliablity, and even though your S1 PTU is ok it is notoriously unreliable. In fact Nissan did a factory recall on all S! PTU's in the U.S, and replaed with S2 versions.

So can somebody tell us IF series 1 have inferior design and prone to fail MORE SO than the S2.

Most places say series 1 are prone to internal connection failure, perhaps because of heat or because they are fragile.

I know they do the same thing but are the internals the same.

 

I'm not trying to claim that S1 always break, but if there is some truth to the myth.

 

My series 1 had internal connection failure so in a way that convinced me (as well as reading stuff inline and being told by people) that they were an inferior design and the problem doesn't happen with s2s.

 

Lets just say this Ali, theres a lot of series one still in service today, I have two perfectly good serviceable units in my workshop. It's a factor of many things that can kill both S1 & S2 units. Let's face it, the hicas unit was changed, certain electrical components, mechanical components etc, not necessarily cos they worked better but they were improved in size and tidiness aswell.

Simple fact is, both units do the same job and both have a service life that's unknown.

Even storage can affect them, like if the car is dry stored, kept warm in the winter, exposed to ice or wet conditions etc.

It's not a simple question or answer it's just a case of if it's still working it's great, if not then replace it.

Obviously changing from S1 to S2 has the extra cost of a loom adapter to change but in my opinion, neither are better than the other. If there's hard facts to prove otherwise I'd stand corrected but the proofs in the pudding and S1 never let me down or the previous owner in 26 years..

Just saying like

There is no intended performance or difference in running intended with a S2 PTU. It is purely for reliablity, and even though your S1 PTU is ok it is notoriously unreliable. In fact Nissan did a factory recall on all S! PTU's in the U.S, and replaed with S2 versions.

 

From what I understand, the US recall was due to materials used that the US deemed hazardous to health. Not reliability issues. I read an article on it on the US z forum a while back whilst investigating the reason for the safety stickers being sold on ebay for the ptu

From what I understand, the US recall was due to materials used that the US deemed hazardous to health. Not reliability issues. I read an article on it on the US z forum a while back whilst investigating the reason for the safety stickers being sold on ebay for the ptu

 

From the horses mouth:

 

NTB94-096 PTU_Recall_TSB.pdf

Lets just say this Ali, theres a lot of series one still in service today, I have two perfectly good serviceable units in my workshop. It's a factor of many things that can kill both S1 & S2 units. Let's face it, the hicas unit was changed, certain electrical components, mechanical components etc, not necessarily cos they worked better but they were improved in size and tidiness aswell.

Simple fact is, both units do the same job and both have a service life that's unknown.

Even storage can affect them, like if the car is dry stored, kept warm in the winter, exposed to ice or wet conditions etc.

It's not a simple question or answer it's just a case of if it's still working it's great, if not then replace it.

Obviously changing from S1 to S2 has the extra cost of a loom adapter to change but in my opinion, neither are better than the other. If there's hard facts to prove otherwise I'd stand corrected but the proofs in the pudding and S1 never let me down or the previous owner in 26 years..

Just saying like

 

I can see your point but you're ignoring everyone trying to correct you by claiming that 'it's 26 years old and mine still works.' series 1 may well be less reliable than s2 but because it hasn't happened to you doesn't mean that it's not the case. Same as I can't claim that because my one failed that they are shite and need to be replaced. This all sparked from someone having intermittent problems with spark and misfires and what have you, which I suggested was a ptu because thats what happened to me and the S1 are supposedly not as robust as the S2.

 

Of course old stuff can break and I'm sure some s2s do fail, but I'm not trying to convince people that they should change to S2, I didn't change to series 2 when mine broke and I dont intend to. But just stop blaming it on old parts and dismissing others because you have a 'hunch'

 

From what I understand, the US recall was due to materials used that the US deemed hazardous to health. Not reliability issues. I read an article on it on the US z forum a while back whilst investigating the reason for the safety stickers being sold on ebay for the ptu

 

It was because they kept breaking :pinch:

 

 

Not having a go, you just seem to be trying to dismiss the problem.