Injector cleaning

Ped

Ped

Club Member
I was going to get my injectors inspected and cleaned on the 280zx. The car runs pretty well, but the exhaust always smells way too rich.

I have a contact who has the facilities and kit to do this. I showed him pics of the injectors and he reckoned they should just pull out after undoing the screws.

My only though was that it would need new seals as they are bound to be rock hard. He didnt seem to think there would be any issues.

So... my question was, are all the parts for these readily available? I guess the seals are, but are the black plastic spacers likely to disintegrate on removal? Anything else I should be aware of?

The part number on the injectors is A46-000001.

Thanks!
 

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Huw

Huw

Club Member
Hi Ped

Couple of things to be aware of. This can be a bit of a pig of a job. It’s easiest to remove the fuel rail completely with the injectors still attached once you unscrew them. As the injector tails will not come off the injectors in situ, unless you cut the hoses. The screws that hold the injectors can easily round off as you try to unscrew them from the manifold so be prepared to replace one or two screws. Lastly are the connectors, worth replacing them if you’re going to the trouble of pulling the injectors. They tend to fall apart once disturbed, age related.

The black spacers normally are fine. They will crack if you over tighten them when putting it all back together.

I have a few spare spacers and screws if you need them.

The seals are still available, again I have some spares if you get stuck.

Lastly, don’t reuse the hose clips. Invest in a set of new ones.

Have fun mate 😋

Huw
 
Ped

Ped

Club Member
Thanks guys. Not in a hurry to tackle this as these things are never as easy on a 40+ year old motor. I think I will wait until the early spring since I have a very small garage. Don't want it sitting outside if I can help it in this weather. I will order up the new connectors and some wiring. I think a couple of them will be a bit neat length wise once I chop the ends off.

Thanks for the offer of spares too, much appreciated.
 
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Ped

Ped

Club Member
Quick update on this. I took the car our for a run the other day and it was OK, but still running rich. When I parked up, then later tried to start it while it was still hot, it cranked for ages before reluctantly starting - but only just.

The workshop manual suggested I test the cold start injector and thermo time switch, which I did, and they are fine.
 
Makesy

Makesy

Club Member
Huw is far more capable than myself, but I attempted to clean and rehose the old injectors and was left with a leaky horrible mess. It gave me an excuse to ditch the old rail/system though and replace it with corrado vr6 o-ring injectors, a billet fuel rail and a sytec regulator
 
Huw

Huw

Club Member
Daft question Ped but have you replaced or checked the temperature sensor? They are a common problem for poor running, especially rich running. The resistance tends to increase over time and the ECU thinks the engine is running cold and lengthens the injector pulse making the mix richer. Worth a measure or replace first as it’s easy and cheap. Might even have one you can try out.
 
Ped

Ped

Club Member
Hi Huw,
I wondered about that, but the temperature gauge seems to work fine, so assumed sender was OK. I will see how the book says to test it. Might as well order up a new one, just needs to be for an early series 1.

Just deleted the fuel filter under the bonnet. I am running a prefilter anyway. Thought it might have had slightly low fuel pressure. Just in from a test run, but issue remains. Will put the second filter back in again.

Cheers for the suggestion.
 
Huw

Huw

Club Member
There are three sensors Ped. Ones the gauge (single contact), ones the thermotime unit (big fat one) that helps enriching the mix at start up from cold and then there is the one thats the potential offender. It has a twin pin socket. That’s the one that tells the ECU how hot or cold the engine is. That’s the fella that needs checking or replacing.

It may not be the issue but it’s the first place to look as it’s tje weak link in the EFI system.
 
Ped

Ped

Club Member
I think this makes sense, thank. Will get onto that next.

The diff is leaking too... so that will get added to the list.
 
Ped

Ped

Club Member
Hi All, have managed to take a pic of the temperature sensor and would appreciate help in sourcing a new one, preferably in the UK. Again this needs to be for the series 1 ie: a 1979 model 280zx.

My current sensor has a number on the white plastic bit which looks to me like 27-000004 with a symbol or letter 'A' in front of it?

Thanks in advance!

temp-sensor-280zx.png
 
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Huw

Huw

Club Member
www.ebay.co.uk

Water Temp Temperature Sensor ECU 2 Pin- For Datsun S130 280ZX L28ET | eBay

Find many great new & used options and get the best deals for Water Temp Temperature Sensor ECU 2 Pin- For Datsun S130 280ZX L28ET at the best online prices at eBay! Free delivery for many products.
www.ebay.co.uk

Got one of these a while back. Might be able to get them cheaper.

May just want to check it first. Should be 2.1k to 2.9k ohms at 20 degrees. Or 0.7k to 1k ohms at 50 degrees.
 
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Ped

Ped

Club Member
Got a message back from the chap. He does not have the spec for the item, but hasn't had any problems. So, have ordered it up, and will give it a go.
 
Ped

Ped

Club Member
Still waiting on the temperature sender. It was posted on the 30th May, 1st Class Royal Mail. I don't know what Royal Mail are playing at. If they want to lose customers they are succeeding. I had to wait ages for another item which was 48 hrs supposedly. It turned up after 6 days... Rant over!
 
Ped

Ped

Club Member
OK, so the temperature sensor I ordered in the UK didn't show up after 2 weeks – Royal Mail – assumed lost. So, I ordered another one from RockAuto on Monday and got it on the Wednesday! Expensive, but quick.

Typically the next day Royal Mail dropped off the first one!

When I went to fit the part the access was tight, so I used a deep socket. Only thing is my sockets are hex. If you notice the black topped sensor (from US). The connector is offset relative to the hex body, so it wouldn’t fit in the socket. Just as well the white topped UK one turned up as that did fit and I could tighten it down properly.

Have now fitted it and had a quick test run. It seems a lot better, no hot start issue and way less petrolley exhaust, but I need to take it on a proper run.

20230617_123544.jpg20230617_123609.jpg
 
Ped

Ped

Club Member
If anyone is interested in the spare black one pictured above let me know, as long as you have a 12 point deep socket (19mm)!
 
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