Looking for help to diagnose my non starting engine issue

[MasterCookieman]

First off sorry for the massive post, it’s been years since I last posted anything, so wanted to be thorough, but it also helped me remind myself of what I've done to date.

The weather is improving and I’m hoping for some help to finally get my Zed running.

To quickly recap, the best I can from memory – after discovery of serious rot (around 2013 I think), I set about rebuilding my Zed, using a donor.  I painted my car myself, and it looked amazing, but a couple months later the paint began crazing and cracking.  To this day I still don’t know why this happened. 

About two years had passed now, I just wanted to get the car running properly so it was driveable, I’d deal with the ruined paint another time.  The engine did run, but badly, even though it used to run fine.  Something must have been disrupted during the transplant from one car to another, the only change was removing the EGR valve, changing the clutch, and replacing the sump.

Codes pointed to the knock sensor.  To replace the knock sensor, I removed the upper and lower intake.  Long story short, little did I know the timing belt had now slipped, despite being warned to check the timing; I was sure it was fine, but of course when I finally started the engine, I broke a couple valves off.  It was not a good day but my own stupid fault.

Ruined paint, broken engine…I considered giving up.  However, I looked through photos and remembered all the good I’d done so far, and the money I’d spent.

So, in 2017 (ish) I got two good used cylinder heads from a member.  I give these a seriously good cleaning, along with the lower intake and the block too.

It was around about now I saw a house and put an offer forward which was accepted.  I suddenly had to divert all my efforts into getting my flat in a condition to sell.  So my Zed was put on hold. 

 

Fast forward to 2019. 

Since moving into the house, all spare time and money pretty much went into sprucing it up (I’m currently ripping out the horrible old bathroom).  However, I finally made time to start putting my engine back together.

I did the following, pretty much in this order -

At some point I bought some stainless headers from the U.S, I don’t even remember when this happened.  My car is an NA, so no turbo plumbing means they do fit, but it is tight, but haven’t managed to fit O2 sensors, so relying on the ECU to use defaults.  I bolted the headers onto the ‘refurbed’ cylinder heads, then I fitted the original CAS and pulleys.

I had bought a used plenum which had been cleaned throughout and sand blasted.  I painted this.  I did the plenum coolant bypass at this time too.  I cleaned and swapped over my throttle bodies, and did the same with the ICV, with all new gaskets.

I replaced all the PCV pipes with new ones, I also replaced the now very beaten and bent rear PCV hard pipe with a section of 10mm microbore heating pipe.  A bit of a bodge I admit, but the original hard pipe was finished.

I fitted the cylinder heads with new gaskets.

Refitted the lower intake, with new gaskets.

Fitted the spark plug plastic inserts and bolted on the new plenum.  I probably attached the balance bar and fuel vacuum doo-dahs at this point too.

Refitted the timing belt, following online guides, ensuring all was lines up perfectly, even to the number of notches between pulleys.  Turned engine over my hand multiple times and am very happy this is perfect.

Connected injectors wiring.  Refitted all spark plugs that were new before I started the rebuild.  Bolted in coil packs and connected the plugs.

Refitted all the pulleys, replaced thrermostat, water pipes etc, and added coolant.

Connected remaining electrical connectors – TPS, CAS, injectors, PTU, MAF, coolant sensors etc.

Refitted air intakes etc.  Checked oil.

Connected freshly charged battery.

 

I was excited, but anxious as I sat ready to turn the key…but when I did unfortunately my Zed didn’t start.

The engine turned over fine, but nothing more, didn’t try to fire up, simply turned over.

I checked all of the connections and pipes, all is fine.

So, I checked that the fuel pump was working by pulling off the filter pipe in the engine bay and on turning over, it filled a glass jar full of fuel, so it’s pumping fine.

Winter came and that was it for 2019.

 

Present day -

In 2020 I (finally managed) to pull off the CAS and manually turned it, so I could test the injectors.  I could hear them clicking, so I assume the fuel is getting into the cylinders.  I haven’t reinstalled the CAS, but had painted it, so know where it was located before I removed it. 

So, next is to check for spark.  I plan to check the PTU, but haven’t found any very helpful guides for this.  I found something that simply suggested checking the output voltage for 12v, with a multimeter.  I’ll give this a shot, but when I came to put the coils back in I discovered I had more than 6, and I couldn’t identify which had been installed originally.  So it’s possible there’s a dodgy coil pack (or more than one) in there, but I’d expect the car to try and start, stutter, shake, something…rather than just turn over.  I’m sure I can test the coil packs somehow, but haven’t looked into this yet.

To check for spark is there any reason this won’t work - https://www.amazon.co.uk/Silverline-633982-Ignition-Spark-Tester/dp/B00157O4YK/ref=sr_1_7?dchild=1&keywords=coil+tester&qid=1591189600&sr=8-7

If I can confirm I have spark and fuel, then next would be a compression tester I guess?

A mechanic that lives across the road who heard me attempting to start the engine; suggested it sounded as is the timing was off, it was missing.  I know mechanical timing is correct, so I considered that could the CAS (electrical timing) be out.  However, until recently when testing the injectors, the CAS has never been touched.  When transplanting it, it was done on the bracket, the position remains the same, so it should be fine, right?  Although, it IS now connected to a different cam, so would this make a difference…  If I wanted to check the timing with a timing light how do I do it when the engine doesn’t run?

I’m looking for any help anyone can offer in diagnosing my problem, basically, what would you be doing yourself if in my position?

I am concerned about spending any more money testing things now, or replacing suspect faulty parts.  I’ve reached a point where I’m questioning where it ends, when I call it quits, I mean it’s been about 9, maybe 10 years since this all started.  I’m not getting any younger (or thinner) and I have a whole house that I need to spend money on.  That said, ignoring my failed paint job, I feel like I’m close to having a working car.  I just want it to start and run, even if it runs badly at first, this should fire up my Zed motivation once again!

 

Things to consider that I ponder at night –

The TPS and ICV will likely need setting up, as they’ve been removed etc.  Not sure if they’d stop the car from starting, but I don’t think they would.  This was a job I had planned when I had the car up and running.

For no good reason, the left pod controls are dead, no display, nothing.  I realise this probably isn’t related, but nothing has changed inside the car for years, and the all electrics worked fine…so a bit strange for it just to stop working.  I had considered that maybe there was an electrical fault caused by me pulling the loom around in the engine bay.  From memory though, the internal loom is completely separate from the engine loom, so it’s probably an unrelated problem.

I’ve never had injector plugs on my loom, at some point someone has cut these off and used crimped spade connectors.  Nasty I know.  When I took these off I made every effort to ensure I was putting these back the same way, as usual taking plenty of photos, but this is another thing that I ponder.

Some photos of some of the above -

https://ibb.co/SmVkLD0
https://ibb.co/cwgFqz2
https://ibb.co/C6p5mBn
https://ibb.co/QnNz3sL
https://ibb.co/wzFpdjg
https://ibb.co/8MJyKYw
https://ibb.co/drNVWks
https://ibb.co/vc2K5qF
https://ibb.co/8DWWW7R
https://ibb.co/zZH4sT4
https://ibb.co/1spCjHt
https://ibb.co/pLBsC6K

[Chris]

Have you run through the simple things first, like fuses?

You say you have changed all the injector plugs, and your neighbour thought it sounded like the timing was off....have you got the right injectors connected to each cylinder? 

[TheRealNips]

Are you using a series 1 PTU? They are know to fail (mine did) and the car will turn over but will not catch. Try a series 2 or different PTU

[Stephen]

Have you been down in the fuse box? I can’t remember wether the car would start but when I had a faulty accessory relay it caused all kinds of issues. This is located in the firing line of a leaky targa drain to. 
Personally I think your “dead” left pod is an indicator of a larger fault. Be worth checking your actually getting power to things like the PTU. It’s been a while but that fuse box does lots of stuff. 

[MasterCookieman]

Thanks for your responses. 

Fuses - I hadn't even really considered them if I'm honest, but yes, I can check these out.  I think I figured they were fine in the past, so should still be fine, but something could have easily blown.

I will check the injector connections again, I'm sure they're in the right order, but assuming the timing is all correct, then if they're in the wrong order this would cause fuel to be injected into the wrong cylinder at the wrong time.  I was actually more concerned that the spade connectors were the wrong way round, as this is what I'm dealing with -

I do wonder what happened in the past for someone to do this.

As for the pod issue, I think I'll check this along with the fuses, see if it's something simple, it's just weird that it's totally dead when nothing inside the car has been touched, other than the ECU to check codes. 

I have a series 1 PTU, and I had considered this as a potential fault.  However, the engine did use to run, so again, although something I've considered, nothing (as far as I'm aware) has changed.  It is something I'll keep in mind and try to test.

Cheers, I'll keep you posted.  Hopefully I can get outside if it ever stops raining...

[TheRealNips]

My series 1 PTU just died, no reason for it to died, one day it worked, the next it didnt. The car would crank, but not fire. Got myself a series 2 and never had a problem since! (touch wood...) If the car has been standing for a while, has a family of mice moved in a eaten through some wires? Crazy, but has been know to happen...

[Chris]

Always check fuses first, I wasted a few hours early this year diagnosing my ABS cus I checked the wrong fuse - I the one I checked was fine, but the real one had blown.

Checking the fusebox for water damage is a good shout if the car was fine before but now has issues after it has been standing.

Worth giving stuff like PTU connectors a good clean with switch cleaner and a brush as well.

[MasterCookieman]

Just thought I’d write a quick update.

I’m 99% certain that all the injectors are connected in the correct order.

I did a basic visual check of all wiring etc from old photographs, taken specifically for this purpose.  Everything is as it should be as far as I can see, the only exception is the two vacant O2 sensor connections. 

I had considered buying some LEDs and pushing these into the injector connectors, hopefully to see when each one is firing…that’s just a thought I’m pondering, not sure if it would work - https://www.ebay.co.uk/itm/10pcs-Miniature-3mm-6V-12V-24V-Lamp-Light-Bulb-Edison-Incandescent-Filament-Rice/174204301531?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20131003132420%26meid%3Df6191fdf4861483c856d9e69ef1d1e42%26pid%3D100005%26rk%3D2%26rkt%3D12%26mehot%3Dco%26sd%3D302546163435%26itm%3D174204301531%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv5PairwiseWebWithBBEV1Filter%26brand%3DUnbranded&_trksid=p2047675.c100005.m1851

 

I’ve decided I’m going to get one of these to confirm that I am getting spark – https://www.amazon.co.uk/Gunson-77074-Spark-Extension-Tester/dp/B003AMXBM4/ref=sr_1_6?dchild=1&keywords=spark+modern+engine&qid=1592255088&quartzVehicle=138-258&replacementKeywords=modern+engine&sr=8-6

 

I went through the fuses, pulled them all one by one, and to my excitement I found a 15A blown in the footwell.  I thought this has to be the cause or some issue, likely the left pod.  However it turned out to be for HICAS/EPS, which I don’t have.  So, odd why there was a fuse in there at all, even odder that it was blown.  I replaced it anyway, and it made no difference to anything sadly..  I checked for a 12v supply at the left pod, but nothing..   Then I found this - https://www.300zx.co.uk/forums/topic/110901-pod-dead/ which details my problem exactly.  So now I’m on a mission to check for a dead accessory relay.  I have a good feeling that this will sort the pod issue.  I now think the pod and engine issues are unrelated, which if true is good.

 

Didn’t get time to look at the PTU at all, as had to go spend one whole hour waiting at the tip to get rid of my old bathroom sink and radiator…

 

[MasterCookieman]

So, I finally made time to spend on my Zed.  The accessory relay was to blame, I had a spare, and replacing it sorted all the electrical issues with the left pod, mirrors etc.  Happy days!

I had come across a long-lost spark tester and compression tester, as expected though the spark tester wasn’t long enough.  I moved onto the compression tester, expecting all to be generally ok, these are the results, they were not ok –

 

Dry Test                     

Cylinder 1        5.5 bar, 80 psi

Cylinder 2        3.5 bar, 50 psi

Cylinder 3        5.5 bar, 80 psi

Cylinder 4        2.0 bar, 30 psi

Cylinder 5        5 bar, 70 psi

Cylinder 6        3.5 bar, 50 psi

 

Wet Test

Cylinder 1        5.5 bar, 80 psi

Cylinder 2        5 bar, 75 psi

Cylinder 3        5 bar, 75 psi

Cylinder 4        5 bar, 75 psi

Cylinder 5        7.5 bar, 105 psi

Cylinder 6        5 bar, 75 psi

 

It’s pretty disastrous, not at all what I was expecting, but it explains why the engine wont run.

I just wondered what you all thought of these results?  My understanding is it points to piston rings….even though the car used to run and drive, but has been standing for years, only turned over occasionally.

It should be noted that I just fitted new cylinder heads, with new gaskets.  The heads were in need of a major clean when I got them, and I scrubbed them well.  When I fitted them, I used the correct torque, and bolting method.  My initial thoughts was that the cylinder head gaskets aren’t sealed properly, but they must be.

[TheRealNips]

Years ago I bought a cheap compression tester for about £20 off eBay and got similar readings and started panicking. I borrowed an expensive tester from a mechanic friend and got results that were in the correct ballpark. I was amazed at how different the accuracy of the testers were, they are only measuring pressure right? Needless to say the one I bought went in the bin. How much was your tester, is it worth borrowing a decent/expensive/branded kit to make sure the results are accurate?

[Stephen]

Glad you looked at the fuse box, that accessory relay is a pain.

If it’s not run in so long and obviously it’s cold those numbers aren’t going to be brilliant. Looks like one bank is lower than the other, significantly. Are you sure you set the mechanical timing correctly when you did the head work? Did you follow the tooth count procedure? 

You can test which injector plug goes where by testing from the ECU pins from the injectors are to the plug. You’ll need some long cables for your meter and a second pair of hands would make it quicker/easier. Label maker and number the buggers once identified. 
 

If you’ve got access to a compressor, a leak down tester or just a bodge to get compressed air into the combustion chamber will tell you so much more. I bet if you hooked one up you’d find air pissing out the head via the valves. 
 

[jimmer]

Why were the head gaskets done ? If it has been boiled at some point it is highly probable the bores are glazed.Those figures are not good and will not help it start if they are actually correct.If you can get it running  they may come up slightly.You will need a really good battery to crank that fast enough and get it started.Have you checked each injector actually works ? I change loads these days that have gone bad,They do not like being laid up for years and that may be the problem.

[MasterCookieman]

8 hours ago, jimmer said:

Why were the head gaskets done ? If it has been boiled at some point it is highly probable the bores are glazed.Those figures are not good and will not help it start if they are actually correct.If you can get it running  they may come up slightly.You will need a really good battery to crank that fast enough and get it started.Have you checked each injector actually works ? I change loads these days that have gone bad,They do not like being laid up for years and that may be the problem.

It wasn't an overheating issue.  The reason for the new head gasket was that years back now, I changed the knock sensor.  Long story short when I did it, the timing belt slipped, despite everyone telling me to check it, I was adamant it hadn't moved (as didn't know the cams were 'spring-loaded' at the time).  Of course, it had moved, and when I turned the engine over, I broke off a couple valves.  I got two used cylinder heads from a member here, cleaned them up and bolted them on with new gaskets.  As for injectors, I've pulled off the CAS and checked I could hear each injector clicking, all seemed well.  Unless they can click and not inject fuel?

 

12 hours ago, Stephen said:

Glad you looked at the fuse box, that accessory relay is a pain.

If it’s not run in so long and obviously it’s cold those numbers aren’t going to be brilliant. Looks like one bank is lower than the other, significantly. Are you sure you set the mechanical timing correctly when you did the head work? Did you follow the tooth count procedure? 

You can test which injector plug goes where by testing from the ECU pins from the injectors are to the plug. You’ll need some long cables for your meter and a second pair of hands would make it quicker/easier. Label maker and number the buggers once identified. 
 

If you’ve got access to a compressor, a leak down tester or just a bodge to get compressed air into the combustion chamber will tell you so much more. I bet if you hooked one up you’d find air pissing out the head via the valves. 
 

I spent a lot of time on the mechanical timing, following guides, making sure cylinder 1 was at TDC and I did count the teeth.  I had considered the timing , I’ve even thought about doing it again, but I really did make sure it was perfect.  I do have an air compressor, and had started looking into the leak down test, it should be fairly easy to do, I think.

I’m fairly certain the injectors are connected in the correct order,  I went back and checked old photos, but also the loom had maintained its shape (like a large stiff claw over the engine), so everything was still in the same position as it was when removed pretty much.  I suppose it is still possible I could have connected them wrongly, but unlikely, though still, possible…   lol

 

12 hours ago, TheRealNips said:

Years ago I bought a cheap compression tester for about £20 off eBay and got similar readings and started panicking. I borrowed an expensive tester from a mechanic friend and got results that were in the correct ballpark. I was amazed at how different the accuracy of the testers were, they are only measuring pressure right? Needless to say the one I bought went in the bin. How much was your tester, is it worth borrowing a decent/expensive/branded kit to make sure the results are accurate?

I’ll see if I can get hold of another tester, I’m guessing the one I have is a cheap thing, but I don’t really know, it’s been around for years and never been used, until now.