Socal_Tom

Good morning - on an early car is anyone successfully running high impedance later style injectors here with the stick ECU and injector harness?

SeanR

I suggest not doing it, use what the car was designed to use. I had low imped in my S4 and it caused all sorts of issues. Sadly, didn't know they were LI until much trouble shooting had been done.

Socal_Tom

Hi Sean-I ask because there seems to be a bit of mixed guidance on this at least as it has been discussed here. Greg Brown, who I was lucky y enough to meet yesterday and is one heckuva nice guy, has beautifully machine adapters that allow you to use a later style injector including ones that have a four hole opening for a better fuel atomization.

Those later injectors however are all high impedance units, hence the question. I have read here that low impedance systems can handle high impedance injectors, looking for confirmation.

Thanks!

Alan

It will certainly be a bigger challenge using low impedance injectors in a high impedance car - it will tend to over-stress the ignition drivers.

The other way round (high impedance into a low impedance car) is much less of an issue. I don't know for sure it would work, but you don't have the same risk of stress damaging the ignition system. Seems from what you describe that Greg thinks it will work fine? - that would be good enough for me.

Alan

Socal_Tom

Hi Alan, hope you are having a good weekend.

To be super clear Greg has not recommended this or sent me on this path. I am going off research I've done.

Alan

Then I'd ask him if his adapters are for use on otherwise stock cars (esp. wrt ignition system).

Alan

Socal_Tom

Hi Alan - don't want to speak for Greg but I believe they can be used for any application so long as the bits all fit.

I am going to stop by FiveO on Monday to see if they have any ideas/suggestions.

Hopefully we can figure this out and add to the options for early car owners.

The Forgotten On

Think of the injectors like a speaker and the ECU as an amplifier. You can only run as low of an impedance of speaker as the amp will allow, otherwise you will overload and damage the amp.

However, an amp can always drive a speaker with higher resistance without issue, just lower output due to ohm's law.

The low impedance L jet computer can easily drive high impedance injectors as it has the power handling capabilities that the LH Jet high impedance systems lack.

Socal_Tom

Hi Blake, thanks for that.

So with that in mind here is the plan;

1) Take my old injectors and Greg's adapters to FiveO on Monday
2) Get their coaching on what off the shelf modern (for best possible injector fuel atomization) and cost effective (so the kids can go to college) injector with the right flow they recommend
3) Document the part numbers and fit etc here
4) Report results back once I get the darn thing running

Hoping to add contribute back to the forum and help future owners.

Sound like a plan?

Imo000

Is there a reason why the existing injectors need to be changed?

GregBBRD

I have no idea if high impedance injectors will work with an injecton system designed for low impedance injectors and told SoCal Tom exactly this.

I've been exclusively selling my adaptors to people with Euro engines that can obtain the correct impedance injectors.

I've told everyone with a US vehicle (including SoCal Tom) that I had no idea if high impedance injectors would work and have suggested that they either clean their injectors or fund good used original injectors.

Tom thought it might be possible and purchased a set of adaptors. I told him several times that if he found out that he couldn't use these pieces, he could, of course, return them.

BC

Low impedance just requires a box in between the ecu outputs and the injectors. It's used often in the after market ecu world. Something about a resistor and some other pieces. Usually made easily with a bread board.

Socal_Tom

Completely and totally the case, let me reiterate again what I said above that this is my line of inquiry and I want to make EXTRA sure that everyone knows that Greg and team did not make any representations in any way here.

Socal_Tom

Hi - the existing ones are totally vanished over and baked on from sitting for 17 years. No way fuel is getting through them.

The Forgotten On

It's the other way around.

People run low impedance injectors on a high impedance system by adding resistors to raise the impedance to keep the outputs happy.