Hi all,

 

Got another issue with the Zed.

 

I picked it up from Lee's on Sat, ran like a dream all the way home. However, after leaving it over night in the rain (as I have no garage), I went for a drive on Sunday (nice weather). I got 2 miles down the road and it started revving erratically and then just cut out completey and would not restart. I had to get the breakdown people out.

 

After spraying a bit of quick start we finally got it going again and he was following me home. It cut out again about half way back and again wouldn't start for about a further 45 mins. Got it going again and it was just revving eratically and changing gears with very high revs. (its an Auto).

 

Finally got it home and checked all the connections in the engine bay and everything seems ok.

 

I tested it again yesterday on the drive way by just starting it up and leaving it to run. It idles nicely while its cold but as soon as it get to operating temp it switches off and won't start.

 

I then stripped back all the carpet in the passenger footwell and found it was damp so I dryed it all out and brought the sponge carpet base in to dry properly. After leaving it over night last night (again raining) the below picture is how it looked. Could this be the issue?

 

If the floor is wet, its ok when cold but as the ECU heats up it lifts the damp and shorts something?

 

I also ran an ECU diagnostic check and it came up with code: 12 - air flow meter circuit

 

Just want to get this sorted as soon as possible now as I'm starting to get really down about it. I can't even drive it back down to Lees now as I would have to stop about 40 times in its current state and then leave it 2 hours before I can do another 2 miles:headvswal

 

If it is the damp, how do I fix the leak? Its not coming from the top of the targa so I am suspecting the overflow pipes. Where are they?

pour water over the car but add bright food colouring, it helps trace where the water is coming in.

Definitely looks like your ecus are getting wet, wrap them in plastic bags for now to protect them

"wrap them in plastic bags for now to protect them " thats a pretty good idea for now.

 

I've heard theres a rubber pipe that connects to something behind the front wheels.... Can't find it though?

Airflow meter circuit could be water in the maff connection under the nose panel get some WD40 on it and give the contacts a good clean. The drivers side front targa drain appears in the space behind fusebox behind the kick panel on the drivers side.

Im not sure but this may be the case on the passenger side too, if so its likely to be behind the block of relays you will see if you remove the kick panel. If the tube has popped off, as they can do, then you need to effect a repair to get them watertight again.

Also give Lee a buzz he will be able to guide you.

Edited June 2, 201510 yr by Iangreenfield

Thanks Ian, would that make it cut out when warm and change gears erratically?

It could be one of a number of things but a dry ECU has to be a priority.

Check and clean the Maff connection though if its wet or corroded then it can cause issues.

Have you checked the usual suspects PTU connections, water temp to ecu connection etc.

I have checked all the connections that I can see, they all look ok.

 

I have found this article though.... My PTU is the older version. Is this something I can just swap for the newer version?

 

http://pexcom.com.au/z32cms/e107_plugins/content/content.php?content.273

I'd give lee a quick ring mate for some advice. Could be a number of things, that front nose panel could be making the maf damp. Changing the ptu is a good mod to do anyway even if it's not the issue.

is the PTU just a straight swap for the newer one? I can only find the newer one on ebay.

is the PTU just a straight swap for the newer one? I can only find the newer one on ebay.

 

Its a very straight forward rewire job, there is a sub harness available for it to convert from the older type PTU.

ah ok. I'll get the ecu dried and sort the leak first and also check the MAF again. If still no better think that the PTU could be the next thing to try.

 

Hate changing parts if I'm not sure its that thats broken:(

Thanks all anyway for helping

I might have a spare s1 ptu lying about ill have a look later.

Thanks Ian, is the s1 the same one as mine?

If your PTU is a box shape with alloy fins on top its and S1, S2's are thinner and smooth.

 

Heres a thread with useful write up in it from Jeff

http://www.300zx.co.uk/forums/showthread.php?156487-targa-drains&highlight=front+targa+drains

I've got a good and known working S1 PTU spare here. Lee took it off my Zed when he hardwired the S2 one in for me :)

Yes mine is defo an s1 then.

 

That write up is really helpful... just need to get on with it prob tomorrow ngt after work now. Looks like a pain to me though lol!

good stuff Mondo, how much do u want for it? Could be worth a try

Yes mine is defo an s1 then.

 

That write up is really helpful... just need to get on with it prob tomorrow ngt after work now. Looks like a pain to me though lol!

 

It is a tight area, you might be better taking the seat out to work on it.

If you are really struggling I might be able to pop over and give you a hand one evening, we can scratch our heads together.

Get some platic sheet and tape it over the targa's to stop more water getting in if your car is outside. Or get on of those half car covers from halfrauds.

Edited June 2, 201510 yr by Iangreenfield

All the signs point to the maff

 

That is a classic problem particularly with a vented nose panel. The fault code confirms this.

 

Try unplugging it and see if anything changes. Take it out, clean up the contacts, clean the wire dry it out and refit. I'm sure there must be a guide somewhere.

Thanks Ian, I'll give it a go first and see how I get on. I'll get a plastic sheet over it when I get home.

 

I should have thought of that yesterday! :blushing:

I'll take that out tonight and have a look. I might also block up the holes on the vents to stop water getting in :yes:

Just a quick one.... if nothing changes when its unplugged I take it its faulty..... sorry if thats a daft question. Just wondering what it should do when disconnected?

Yes mate,

 

The ecu will go into limp home mode if the voltage is outside of range, so disconnecting shouldn't make a difference if there is already a fault.

 

If it's in limp home it won't rev over 2500rpm

 

Swapping for a known good unit is a good test

 

Be aware that the fault may not be with the actual sensor of the wiring/ecu has got wet

If the ecu has got wet, should it be ok once its dried out or will I need a new ecu?