Standard Motor Products injectors?

Ive stumbled across these FJ516 injectors

sounds too good to be true?

FJ516…yes…too good to be true. I bought 9 of these in 2012. 11 years ago. The flows compared to OEM Bosch units are waaaayyyyyy off. I tested them on my bench tester. The pre-HE Jag operates at 2 Bar fuel pressure.

At 2 Bar, the OEM Bosch units flow +/- 370 cc/minute.

FJ516 at 2 Bar +/- 448 cc/minute.

That’s a 21.6 % difference.

I was able to find a SMP engineer to share that data with and attempt to find a suitable SMP replacement. Never went anywhere. Apparently no one at SMP has any data charts with flows. That’s at the injector mfg plant I think in South Carolina. How they get away with that is beyond me.

The pre-HE pressure regulator is adjustable. What the low range is I don’t know. To make the SMP flow at the same flows as the Bosch OEM injector, the fuel pressure would have to be dialed down to +/- 19.5 psi. I don’t think that’s possible.

SD Faircloth

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It seems amazing that SMP wouldn’t take your feedback and fix the problem- maybe they dont care

looking further in the smp catalog and cross referencing a bosch specs list (i found ‘motor west’ on google

I got FJ516 supposedly equivalent to 02801050045, which seems much the same as 0035 at 2.0 ohms and 410cc/min

There is also FJ119 to consider - apparently equivalent to 007, which is also 2.0 ohms, flowing at 340cc/min

if that were also 20% over delivering then it would be about right ?


I wouldn’t assume that an apparent error in data on one injector flow rate (FJ516) translates into the same error on a similar injector by the same mfg. I am very cautious at relying on flow data on the net, mainly because the data is so easily maneuvered around and copied…many times incorrectly. The most common I see with injector flows is someone will add a number into a flow chart that an injector flows say 300 cc/minute at 3 Bar…when in actual practice the flow is 300cc/minute at 2.5 Bar.

As for the other injectors you mention by SMP, I don’t know. You could opt to buy one of each and have it flow tested, and if it’s close…say within 10%…you could do some pressure variation calculations to maybe dial it in. Problem is, you would have to replace all the injectors, you couldn’t mix brands with different flow rates. SD Faircloth

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makes sense
my injectors are ok, but it seems a shame that they didn’t go to the trouble of making their products fit for purpose

If I were Bosch, I would have designed injectors to operate at a range of fuel pressures, with the flow rates obviously varying with fuel pressure. And the minimum flow of one type of injector at the lowest fuel pressure would overlap the maximum flow of the next smaller injector operating at maximum fuel pressure. Hence, with just a few standardized injectors and adjusting the fuel rail pressure, I could meet the requirements of any engine.

But that’s just me.

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Doesn’t the ecu in later cars cover this by varying the injector hold time deduced from the feedback from the o2 sensors?

Yes, but the range is limited.