Hey

 

Some of you might know, but my car is running on 5 still. I was under the impression that it may be the coil pack, so after checking all the plugs and finding only one that was obviously not arcing I changed the coil and crossed everything. It didn't work. The coil was not at fault.

 

Running out of ideas now, but I am just about to do the most simple and change the sparkplug incase its that, but I have some questions.

 

So my questions are:

 

Could it really be something that simple?

 

Is there any way to check for a spark?

i.e. Remove the coil and plug and spark it against something.

 

Is there any way to check the plug connection to the top of the coil?

I.e. Volt meter or anything

 

Has anyone any other ideas?

 

Thanks in advance.

You can check for a spark by removing the plug and coil and grounding it on the engine somewhere.

Worth reading the workshop manual for diagnosis steps. Its in the FAQ section and shows you the proper way of doing the checks.

it maybe the plug that connects to the coil pack on the wiring loom side as the wires have a tendancy to go brittle

Also, the cooling fan is on constantly evern when started from cool in the morning. Any simple check for this problem?

could also be the output from the PTU to the coil, usually they fail completely but have been known to fail on 1 cyl

But according to the guy I got the car from the PTU was changed.

 

Anyone round Southampton got a good one I can try please?

did it have a new series 2 or a 2nd hand series 1 PTU tho, the old series 1's are very prone to failure if they replaced with a 2nd hand one.

 

there are some tests here:

http://www.300zx.co.uk/cgi-bin/manual.cgi?list=efec&dir=&config=&refresh=&direction=forward&scale=0&cycle=off&slide=118&design=default&total=190

 

they are not always conclusive & sometimes trying a known good PTU is the only answer.

Thanks.

 

Come to think of it, it must be the PTU because before it died the car was running sweet, then after it was changed it ran on 5. Nothing else changed.

 

Right, I need another.

Change the sparkplug that was not sparking, and still nothing.

Also, the cooling fan is on constantly evern when started from cool in the morning. Any simple check for this problem?

 

sounds like the temp sender is faulty, or needs a good clean

acts like a choke and tells how much fuel to put in,

dead easy to swop/clean

 

#14

 

http://www.300zx.co.uk/forums/showthread.php?t=26120

Simon

 

The replacement PTU was a Mk1 and was seen running on the sellers car before handing over the cash.

 

The auto electrician diagnosed that connections in "1" and out "1" on the old PTU were not giving a reading.

 

And as stated before, the car was running sweetly before the problem. Which reared its ugly head after a prolonged period of idle in hot, direct sunlight conditions, with the bonnet raised whilst idling.

 

Trust this info helps.

 

apprentice

Ok. You are never going to believe this but here it goes.

 

Was fiddling around in the engine bay this morning trying to solve said problem, and decided to investigate the PTU, in order to remove it. Removed the pipe work above it and checked the top plug. There was no problem with the top plug so I plugged it back in. I then moved down towards the lower plug and removed the metal clip, I then decided to make sure the plug was attached correctly by moving it....it then clicked into place....started the car and it ran sweet as a nut!

 

All this worry for nothing. Turns out all it was is that the plug was not connected flush. I am now one uber happy bunny who has been enjoying the zed to its full potential since! I have now purchased the remaining 5 sparkplugs and will replace them all tomorrow.

 

I would just like to thank everyone for their help in this matter, and hope this silly episode will assist others in the future! Thanks again.

With regards to the fan I have also found the problem.

 

The yellow plug on my car is broken and needs attaching with a zip tie, thats all. Damn this has been a good day!

glad its sorted

With regards to the fan I have also found the problem.

 

The yellow plug on my car is broken and needs attaching with a zip tie, thats all. Damn this has been a good day!

 

That tellow plug is for the temp sensor. Make sure the inside of the plug is clean and free from verdigris. If not a quick fix is to cut it off and solder on a spade terminal.

Great news Simon... I knew it had to be something straightforward!

 

Enjoy it!!

 

Take care,

apprentice

Thanks again Pete. You are a gent.