fitting blue r injectors to 740 turbo

Hi all, after some reading I've found that the blue r injectors as found on s60r's etc (bosch part: 0280155830) will fit and run on my 740 turbo's B230ET under Motronic management.

I'm lead to believe that they are a direct swap for the original 280 150 357 injectors save for the fact that these are low impedance and the new blue ones are high.

Apparently I need to bypass a resistor somewhere so my question is, can anyone please tell me where these resistors are located and exactly how to go about doing this?

Thanks in advance.

The resistor is a bunch of ceramic dooberys held together in a metal frame bolted into the inner wing.
But the important question is, why?
Are these injectors bigger than stock? If so, they'll just make the car run really rich and make less power. The Motronic ECU does not have a lambda sensor feedback system and cannot scale for the bigger injectors. What are you trying to achieve?

Although the 740ET may run Motronic, it is an early type, probably ME 4.3, which uses EV1 or pintle style injectors. The Bosch data says thse flow 333 cc/min @ 3 bar, 2.4 ohm

The R injectors are the later style EV6 4-hole plate style, flow 373 cc/min@ 3 bar, and are 12 ohms.

These are not a direct fit or swap. If you use the 740ET computer to run them w/o the 740T resistor pack, the common injectors for the LH 2.4, 3.1, 3.2 and ME 4.3 are 15.9 ohms, so there will be a slight mis-match and the computer may not trim fuel correctly, as lower resistance will open the valve more than the ECU is expecting and provide excess fuel.

BTW, the S/V70 R's use ME 4.4 to drive the EV6 injectors, and AFIK they all have closed loop Lambda feedback.

That being said, the ECU pulse timing between the EV1 and EV6 injectors is quite different, older EV1 is 200 ms and EV6 is 50 ms response time IIRC. This mis-match in timing results in ~10-15% less fuel delivered for the same injector when used in the EV1 ECU. So a 19 lb/hr drops to 16 lb/ hr flow.

There have been several others experimenting with EV6 injectors in a old LH car that has EV1 ECU drivers, and I am one of them. I have 850 N/A EV6 injectors in my 91 245 LH 3.1 car and it runs fine, but slow. They flow much less than stock injectors, but the car runs smoother but better mileage.
I do have a concern about the older ECU driving the faster EV6 injectors and frying the ECU to over-driving the injector drivers when it is under high load and can't get enough fuel to trim properly in closed loop feedback. I have already fried one rare 3.1 ECU, so will go back to the EV1 style as soon as I get some good re-man injectors.

Try them, it may work OK, but you take the chance it won't work well in the long term.

so what your both saying is that IF Motronic utilized a Lambda sensor then bypassing the resistor pack may work on the basis that the injectors would be opened wider but less frequently (or quickly?) - perhaps a bit like changing the profile of a cam acting on valves -

I wish I understood injection and engine management properly so that I could fit mega squirt, but every time I try to read the manual my brain recoils in favour of something more visible and mechanical.

There are a number of reasons for the idea. Firstly Chesh suggested it might be a good idea to me a long time ago but I can't remember why. I just assumed in my engine management ignorance that more cc meant everything else would adjust itself to give more power. Some posts and articles don't read precisely like that but do report people using them with Motronic without issue. And finally, I believe my original injectors are blocked (I accidentally ran the tank to empty a little while ago) and I can get a set of blues cheaper than a set of originals so I thought I'd try it if possible.

Motronic ET

The B230ET 740 Turbo is a UK market model which was never sold in the US to my knowledge. They used a Motronic 1.1 system, which is a combined fuel and ignition ECU using a flap type airflow meter and no lambda control.
The fuel map is fixed, not scaled from a lambda sensor, so fitting larger injectors (if they worked) would simply inject more fuel all the time, everywhere. At idle, at cruise, etc. This is not good.

The ET engine has a decent flowing head and a large T3 turbo. The injectors are big enough for a decent power increase already. My tuning tips for the ET would be the following:
* I 'think' the ET injectors are identical to the later 940 FT/FK injectors, which might help you find some. I may have some kicking around. PM me. Failing that, just get your's cleaned. A sensible precaution if raising the boost anyway.

* Block off the hot air inlet to the airbox and open up the cold air inlet a bit more.

* A 2.5" exhaust from the downpipe backward. One very big absorption type silencer is enough.

* A chip for the ECU to remove fuel cut. Any one will do, they all work in the same way. The Viking chip has a higher rev limit though, which is sometimes useful. PM me about chips.

* A MBC set to about 0.95bar. Listen out for knock and back it off a little if necessary.

That is about the limit of the standard setup. Beyond that you'll have to fit a larger air mass meter, probably larger injectors to match that and then completely reprogramme the ECU with a new map the suit the new components. So much work you'd be better off going with a different ECU entirely. Believe me, what I've described above is what Rolls Royce would call 'Adequate'. Enough to spin the wheels in the wet at 80mph....

Thanks for all the helpful info crog I really appreciate it.

I also have some 0 280 150 804 injectors from a 2.0 turbo, do you know if they would work in the mean time?

With regard to the mods:

* I have a cone filter replacing the original induction box.

* I have a Varex rear silencer awaiting me to source/make the rest of the pipe to fit it - so the exhaust is still standard at the moment.

* I'm currently running a BSR chip but I also have a Viking one to try out.

* I have a Greddy EBC which has been set to 14psi (approx 0.95bar) for ages with no issues.

* And finally a larger AMM (flap type as original but larger) which I stole from a 7 series BMW.

So perhaps that's what Chesh meant, I should have been running the blue injectors to match the increased air intake from the BMW AMM, or does it not work like that? I'll PM him to take a look as I don't want to bad mouth him, it's probably my memory failing on what he meant.

Jimathon?

Doesn't Jimathon on the UK VoC board do fully cleaned injectors on an exchange basis? I thought he used to. IIRC he ships out injectors he has in stock the moment he receives your dirty ones and the very modest money, then puts your into stock after cleaning, for the next guy, and so on.

beavy69 said:

I also have some 0 280 150 804 injectors from a 2.0 turbo, do you know if they would work in the mean time?


* And finally a larger AMM (flap type as original but larger) which I stole from a 7 series BMW.

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Stock 804 injectors from a B230FT (B200) are 334cc/min.

If you have a larger air flow meter then the ECU will see a lower voltage as it thinks less air is entering the engine than acctually is so will reduce the injector puls width to run what it thinks it should. With no feed back from an oxygen sensor the car is blind to how rich or lean it is running so your car is basically an open loop system. Do you have a wideband oxygen sensor? If you haven't then I would suggest one. How much bigger is the 7 series air flow meter than the Volvo one?

beavy69 said:

so what your both saying is that IF Motronic utilized a Lambda sensor then bypassing the resistor pack may work on the basis that the injectors would be opened wider but less frequently (or quickly?) - perhaps a bit like changing the profile of a cam acting on valves -

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No, not that. The fuel maps in the stock ECU will be a mis-match to these injectors even if you have a closed loop. Then add the mis-match of the resistance and timing of the EV6 type and it cam be a can of worms without a closed loop feedback system.

It soulds like you've already experimented with the engine management, and to do what you want you will need to tune on a dyno and set fuel maps into a custom chip to get there.

I would suggest trying the smaller MAF from a BMW 525e (US model) which uses ME 1.x, and is smaller than the 740 MAF. I would guess that the 740 MAF is calibrated to a much higher air flow than the B230ET has.
The WB O2 sensor will get you in the balpark, but experimenting without help of a dyno would be like chasing your tail.

As mentioned above the motronic system has no protection from running lean.

The Blue R Injectors and the BMW AMM were a known way of getting that little bit more out of motronic cars, The motronic system was used across europe and there were quite a few modifided Motronic 740 turbos from sweden back in the day.

yes it'll make it run richer elsewhere, but in essence it is at best hack tuning and the use of a wideband gauge to measure the AFR Ratios is essential.

When i ran motronic way back in the day, the afr's would go quite lean up top.

There is the motronic suite availabe that allows you to write your own chips, but as its quite laborious, fitting an aftermarket ecu seems far prefable.

I allways knew i was pushing my motronic setup to the limit and had trial fitted megasquirt a few weeks before the valve let go destroying the engine and my interest in building a performance redblock again.

The engine when pulled apart showed signs of detonation, but if your prepared to be carefull and not that worried if the engine goes bang, late b230ft's are reasonably plentifull should you need to.

beavy69 said:

* I have a Varex rear silencer awaiting me to source/make the rest of the pipe to fit it - so the exhaust is still standard at the moment.

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Turbo cars are so quiet anyway there's not much point. Just make up a 2.5" system from the standard downpipe backwards. It will make more power from the same boost, make boost sooner and generally make the car a lot nicer to drive. I used an Jetex system I got off Chesh, with the rear silencer replaced with a straight pipe.

beavy69 said:

* I'm currently running a BSR chip but I also have a Viking one to try out.

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They are the same apart from the rev-limit, so don't expect any more power. Makes you less likely to hit the limit when changing up very close to it though.

Thanks everyone for the info its really helpful.

I had to get the car moved to where I can work on it and while the RAC man was with me he asked if we could try something. He got me to crank her over while he wacked the aux fuel pump (under the car not the tank one) with a rubber mallet. and it almost got it to start. Spraying carb cleaner in the intake also got it going a bit so he though it was the fuel pump rather than the injectors.

Question is, with fuel pumps (as I found from Volvo today) being ?240! Can anyone tell me which other models I can pinch one from?

I'll switch back to the old smaller Volvo MAF and hang on to those blue injectors until I can implement all that properly.