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Online guide to fitting injectors?

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Hi, I just wondered if anyone knew if there is a guide anywhere online on fitting injectors?

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GRRRRRRRRRRRRRRRR browser just lost my effin post.

OK IF Royal Mail get off their ass and deliver mine I could go in further depth...

1) Run the car, pull the fuel pump fuse, relay etc to starve the engine - then try and start it for a few secs to drain the fuel from the rail as much as possible. Disconnect the battery.

2) Get a towel and put it under the main fuel rail connector and crack the nut, fuel will likely pish out so make sure you have something to soak it up and dont let it get on anything that might be hot.

3) Pull the leads on the injectors

4) Undo the 2 bolts facing diagonally up towards the chargecooler that hold the rail down (think there is only 2....)

^^ You can see along the rail here, dunno if they can clear the chargecooler or not, fingers crossed they can - as you can see I took the chargecooler off when replacing the inlet manifold.

6) Gently prise up the fuel rail in line with the injectors - the can be stiff as buggery so be careful - there are also clips securing each injector so ping these off as well, they can ping off when you pull the rail up so be careful of losing them

7) Job done really - might be worth replacing the o-rings

Be totally mindful of the fuel as well - goes without saying really.

Have some rags ready to mop spills up asap - best done also with the engine cold

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You will need to take the chargecooler loose and move it out of the way. You can leave the coolant hoses attached.

Definitely replace the o-rings and lube them before inserting the injectors. Also make sure the injector holes in the manifold and fuel rail are clean and free of debris.

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Pukka, thanks guys

I hoped it'd be that easy. Just sizing up those main and secondry injectors from WC.....They look awfully good value.....

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Personally I would buy the BOSCH. Nothing against WC or the Lucas injectors. just $$

For the Primaries I bought the 36lb/hr (370cc/min), LOW impedance 2.8 Ohm

"Peak and Hold" Bosch Ford injectors. Part # Bosch/Ford E5ZE "36lb Bosch-Brown Top 0280150803"

They were $46 each and are the same flow as the stock Lotus primaries.

For the secondary (plenum) injectors, I went with a little larger 19lb/hr

(200cc/min), High Impedance 14 Ohm "Saturated" Bosch injectors

Part # Bosch 0280150556-D5B-19lb* I bought the two for about $26 each.

I bought them from

this was a long time ago, so prices may have changed...

Edited by Vulcan Grey

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C'mon then Jonathan, heres another Q

Whats the flow rate of the standard fuel pump on the S4S?

Thinking further down the line; Wondering if its possible to put a beefier pump on to make absolutely certain that the new improved injectors never get starved. Does anyone have any data that either does, or does not show if the current standard setup can absolutely cope at full boost with the fuelling required?

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The new injectors you would (eventually, mine are taking 2 months + atm......) get from WC engineering are not higher flow, it's the spray pattern and quality.

Aparently the ones on the std car are pretty basic and have a poor effect on atomising the fuel with the air - the new ones, apparently, do a much better job and are of a higher quality so you get better idle and smother response - we'll see, not disbelieving the ppl who have fitted them at all - it's just that my GT3 is lumpy and the guy who did my driver training noted with a better throttle response my driving would improve so i am hoping, but not getting my expectations up too far just incase.

Flow rate of the pump ? Havent a clue (sure someone on here does) but the pump 'should' be OK for standard applications.

Where it all changes (feel free to step in anyone...) is when you increase boost, this is the job of the secondary injectors to maintain the correct fueling for high boost situations.

As standard the secondarys and the original pump are highly likely to be fine. The 300 Sport had a higher rate pump iirc...I would hazard a guess that the S4s pump is right on the upper limits of it's performance range for this engine.

Obviously if you start to increase boost you should increase the performance of the secondary injectors.

Standard I'd leave it be - no harm in adding a better pump but I dont think you need it.

If you're chipping / over boosting and planning on buggering about with an otherwise perfectly (and extremely) quick car :respect:

...then you need to look at bigger secondary injecotrs and pump to maintain the air:fuel mixture.

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nahh, not thinking about chipping

Just wondering how far 'standard' can be taken? In otherwords, well, a better 'bang' in the cylinder from a better air/fuel mix quite simply has to mean a smidgen more poer overall, with a decent increase in torque through the range, and of course a potentially massive leap in driveability....

Now, is this is the case, then assuming better secondarys has been installed then they have a far greater chance of maintaining the fuelling whilst utilising zee booooost. So, a more stable power band should be achieved along with, again a better 'bang' and in theory more power for the same amount of boost...

I am wondering where the standard setup can be updated and improved to produce more torque, power and mid range punch. Not thinking about upping the boost or chipping.

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Man after my own heart.... :respect:

Think breathing - filter, ram intake, free flow exhaust (you've done these ?)

Chargecooler has a massive effect on performance - im working on an insulator atm to poke under the charegcooler body to insulate it from the engine - plywood construction really easy mod.

regard le graph :

Better gas flowing of the inlet, although some people insist rougher edges aid turbulation on a forced induction car.

Remember the S4s and indeed the GT3 I own are really pushing production levels of reliable power - YES more can be had but really, on a turbo car, the easiest way is to crank the boost up - crude but initially very cost effective.

Then you start to wade into turbo efficiency - extra heat soak into the chargecooler, fueling, more frequent servicing and so on - IF you want to do it properly.

Lots of people just stick a chip in and be had with it - fine, but I know more than a few of them have gone pop.

The biggest thing about driving the turbo too hard is heat.

When he std turbo goes above it's efficiency range it generates huge heat in the compressor - which by law is hard to compress which means for a small step up in boost you need quite a bit more RPM on the turbo - it's definatly not a linear factor, doubling the boost is like quadrouple the rpm.

The GT3 I own will one day have about 1 bar of boost (up from 0.85) but only when I can program my own chips and do it the way I see fit, and really thats all you need, in the real world.

As I say there isn't much that can keep up with an S4s on full chat upto 120mph, there's very little in it between a V8 Esprit to 100mph - depends what you're after.

Anything you do will cause extra wear on components and it does depend on whether you want a top end machine, track car, or a toy for booting off the lights.

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