Injector cleaning

Makesy

Club Member
Glad to hear you got it fixed Ped.

Well done Huw!

We should have a counter of # of issues Zclub membership has helped resolve
 
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Ped

Club Member
Well, the fueling and hot start issue has returned!!!! Ahhhhhr!

I am guessing either the new sensor has failed, or there is a wiring issue? I redid this wiring connector with new wires, so not convinced it is. I have the other sensor so will probably just swap that out first. Glad I didn't refill it with antifreeze yet, I must have known... Will get a cheap 19mm deep 12 point socket.
 

Huw

Club Member
Oh bugger, well that’s the first component to check. Next on the list to check for ‘car won’t start when hot’ is the cold start valve and the thermotime switch. Attached are the checking procedures. Sorry they are photos, my scanner is caput.



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Ped

Club Member
Oh bugger, well that’s the first component to check. Next on the list to check for ‘car won’t start when hot’ is the cold start valve and the thermotime switch. Attached are the checking procedures. Sorry they are photos, my scanner is caput.
Just as well I have two sensors. The one I fitted had been kicking around in the Royal Mail system for two weeks, surprised it worked at all! EXTRA:D

I did check the other items first as per the manual and they seemed good.
 

Huw

Club Member
Alrighty, the last component to check is the airflow meter. You can only do two checks (in the attachments to my earlier post) a mechanical check of the flap, could be binding when it gets hot but unlikely, and the resistance check of the air temp sensor. After that it’s down to checking for wiring gremlins.
 

Ped

Club Member
Alrighty, the last component to check is the airflow meter. You can only do two checks (in the attachments to my earlier post) a mechanical check of the flap, could be binding when it gets hot but unlikely, and the resistance check of the air temp sensor. After that it’s down to checking for wiring gremlins.
Thanks, not sure when I will get onto it. :confused:
 

Ped

Club Member
Have ordered up a cheap 12 point socket from B&Q... £2.24! :EXTRAlol: Probably only ever need to use it this once. I'll pick it up this evening.
 

Ped

Club Member
Quick update. Swapped temp sensor for another new one, cleaned up all the connectors and checked the wiring for anything obvious. Went for a run and it is still over-fuelling and still has the hot start issue! Bugger.

I noticed the earth cable isn't in great condition and that on the last couple of outings the battery hasn't been fully charged, even though it has been on a trickle charger. When I do get it started and press the 'computer' test, it cycles through and the battery is showing as yellow, not green. The battery is only about a year old, hence I wonder if the earth cable is part of the issue? Regardless I am going to replace it.

Any suggestions on where to get a new one?

PS: The injectors are probably in need of cleaning, I'm just putting it off.
 

Robotsan

Club Member
Quick update. Swapped temp sensor for another new one, cleaned up all the connectors and checked the wiring for anything obvious. Went for a run and it is still over-fuelling and still has the hot start issue! Bugger.

I noticed the earth cable isn't in great condition and that on the last couple of outings the battery hasn't been fully charged, even though it has been on a trickle charger. When I do get it started and press the 'computer' test, it cycles through and the battery is showing as yellow, not green. The battery is only about a year old, hence I wonder if the earth cable is part of the issue? Regardless I am going to replace it.

Any suggestions on where to get a new one?

PS: The injectors are probably in need of cleaning, I'm just putting it off.

I've had issues with trickle chargers. The ctek one just won't keep my M3 battery charged, and keeps trying to tell me there's a fault with the battery. Yet if I disconnect it and just use the car regularly (ie once a week) the battery stays charged perfectly well.
 

Ped

Club Member
280zx_inlet.jpg


I got time on Sunday so stripped the fuel rail and injectors from the car. I've been putting it off cause I'm not 100% sure this will be the issue... the jury is out. Luckily they came apart no problem, other than getting the "just 1mm too long" stud out holding the fuel rail to the front of the block. I'll get a proper bolt for it. Gave the inlet manifold a bit a clean, although it doesn't look like it int he pic!

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280zx_fuelrail.jpg


I dropped them off today at my contact who has a testing rig. He is cleaning, flow and pressure testing them, so should have an answer whether they are OK on Thursday. I have a set of seal kits which I got from the States, they look about right. It came with the o-ring seal to inlet (smallest one) and a isolator bush, plus another thicker isolator (for a different application?).

280zx_seal-kit.jpg


So nothing to do but wait, fingers crossed they are OK and were just dirty. Although the new inlet seals should help too. If this doesn't fix it it will likely be the airflow meter, but just going through items one at a time.
 

Ped

Club Member
So the injectors have been cleaned and checked are are good! I put them back in at the weekend and it's running pretty well (the fuel rail is a bit of a pain to get back in while making sure the injector seals seat properly). It's not too rich, but it's still not quite right.

The hot start issue is a lot better too, but it still not quite right either. I tested the coil and it seemed fine – as per the book, but I haven't double checked it when it's hot. Off to a meet tomorrow evening, so will see how it performs and will retest the coil when it's hot.
 

Ped

Club Member
I went for a run over to White Waltham Airfield for the last classic car meet up of the season there. The car was nice and warmed up so I tested the coil and sure enough it was out. The book states a resistance of between 0.84 – 1.02 ohms, anything outside this is considered no good. Mine was showing 1.2 ohms. The car restarted, but not very easily. Anyway, I have a new coil so will fit that and see if that really is the problem....
 

Ped

Club Member
New coil fitted and car running a bit nicer, but still not perfect. Hot start issue improved, but not gone. Have ordered new plugs, should get them tomorrow.... getting there, I hope.
 
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