Injector replacement and what not to forget...

[RobinB5]

Never replaced injectors before, didn't even know what they looked like, but thanks to various threads on TLF I managed, to my surprise, to successfully replace the injectors and the fuel filter whilst I was at it. Couple of things to remember for next time: remember to put the 15A fuel pump fuse back in and reset the fuel cut off switch before attempting to restart her. It will save on swearing and the use of nasty words.

 

[Barrykearley]

Well done chap - they are surprisingly easy cars to work on the esprit 💪

[Mysterae]

What was the reason for replacing them? Reliability, performance or the old ones just getting old?

[RobinB5]

7 hours ago, Mysterae said:

What was the reason for replacing them? Reliability, performance or the old ones just getting old?

I know that 'if it ain't broke, don't fix it', but she's pushing 95k miles, there's a noticeable amount of soot coming out the exhaust and the idle is quite lumpy (cycle by cycle variation). Also I wanted to take my maintenance experience to the next level  (I don't have much of a history of working on cars). Looking forward to seeing what the effect on performance is though, shame the weather is forecast to be biblical today, will have to wait.

[RobinB5]

Should have done a before and after recording of idle. Here it is afterwards though, noticeably smoother:

 

[Giniw]

It sounds smooth indeed, the engine doesn't move much

 

Could you have a look at the original injectors filters please? I would like to know their dimensions so that would be nice if you could pull them out of the injectors (but I think the basket filters will be good for nothing after that so if you want to keep them that's not a good idea!)

[Giniw]

PS: if you intend to bin them I might be interested to have them to have a look before I do anything to mines (I don't really want to remove them from the car before I have the seals & new basket filters)

[Mysterae]

Preventative maintenance is as good a reason as any . I'll be adding that to the list then for my planned rebuild, she's once round the clock at over 103k.

[RobinB5]

Jesus bloody Christ, just taken her out for a spirited drive and come back hands shaking. Literally like a new car. So much more power laid down, so smoothly. Scared this shit out of me and I totally loved it   Everyone replace your injectors now !!!   

4 hours ago, Giniw said:

PS: if you intend to bin them I might be interested to have them to have a look before I do anything to mines (I don't really want to remove them from the car before I have the seals & new basket filters)

@Giniw, quote me a price, happy to sell on.

[RobinB5]

For those interested, here the spec of the SJS supplied (RC) injectors. Don't know how they compare to stock performance (S4), anyone?

 

At lest all four spray patterns are "Excellent"  

[Barrykearley]

I’m now somewhat confused after hunting for injectors.

what @RobinB5 has are PL2-320 rc units as can be seen on the spec sheet and the injectors.

Here they are - listed as Elan units?.

https://www.fuelperformance.co.uk/index.php?route=product/product&product_id=13296&search=Pl2-320  

they are suggesting Esprits are PL2-370?.

https://www.fuelperformance.co.uk/index.php?route=product/product&product_id=5074&search=Pl2-370
 

so what are the originals - 320 or 370cc ?

[Barrykearley]

Standard 5235364 Rochester injectors are spec’d at 370cc. 

[Barrykearley]

Secondaries are SL4-270 units or D3764BA

[fjmuurling]

AFAIK the primaries should be 370 cc injectors.

I fitted PL2-370 RC Injectors in my SE.

[Barrykearley]

So begs the question why an esprit specialist has sold @RobinB5 these units. Get on the phone to them chap and request the correct parts 👍

[RobinB5]

On it...

[Chillidoggy]

With any potential performance gains, I like to see a before and after dyno power test. Seat of the pants doesn't do it for me!

[RobinB5]

Well could have been imaginary wishful thinking for sure. Certainly felt totally different though.

But they're being sent back for a refund, the supplier can't provide the PL2-370s. Caveat emptor.

Edit: apparently they should have sent 370s, now being sent back for replacement!

[RobinB5]

Thanks everyone, ah the power of TLF.

[Barrykearley]

This sort of thing really boils my p£ss.

correct items ordered from a well respected specialist. Had @RobinB5 not sent me pics of these - no one would ever have known these were wrong - with the very real potential issue of that engine running lean and a costly rebuilt.

absolutely abysmal. for the record the post above referring to SJS as the supplier is incorrect - it’s not my place to name the actual supplier though.
 

save yourself using the specialists and buy direct from the uk source

https://www.fuelperformance.co.uk/index.php?route=product/product&product_id=5074&search=Pl2-370

 

[sailorbob]

The OE primary injectors are rated at 34.13 lb/hr (358.4 cc/min).

[mike_sekinger]

The RC Injector flow check is performed at 43.5PSI, so that 320cc/min relates to that reference pressure.    What fuel pressure does the 4-cylinder car run?  

[Barrykearley]

30.5-55lb/sq.in

the 320 are just plain wrong.

[RobinB5]

So if ~360 cc/min is required with the PL2-320 injectors I'd need ~49 PSI pressure in the rail (assuming linear pressure vs flow rate). This is on the upper side of the quoted pressure range. So safer going for the 370 cc/min injectors as I assume it's better to have the capability for greater fuel flow rate as opposed to less?

[Chillidoggy]

Just a thought - how do those injectors match up to the originals resistance-wise? I seem to recall someone mentioning that ECUs can sometimes be a bit choosy.