Fuel 5.0 Injectors on a 2.3

I bought these 5.0 injectors and was planning on putting them in my 2.3l today but im hesitant and need a push in either direction. I see some saying this will make the car run a little better, some say it'll slow it down and others that it'll fry my ecu. I've not got much done to the car except upgraded fuel pump, ignition and open exhaust. I don't mind wasting some fuel while I get more done but I don't want to risk damaging anything either.

General karthief said:

Is it speed density or maf?
what year?

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It's an 89 with speed density

KRUISR said:

Why would you need bigger injectors on a 2.3? Without some kind of tuning you will run very rich (assuming this is a NA 2.3).

If it is not running right, give it a full maintenance tune up.

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Well I have replaced the entire ignition system, everything in the fuel system except the lines, injectors and pulse dampener, new cooling system, oil change, new tfi and ignition switch and timing is perfect. I figure the only thing that could still be wrong is one of the stock injectors are clogged or malfunctioning. Since I am going to eventually need the 19lbs I was just trying to avoid buying the stock injectors by putting these in now. I'm good with it running a bit rich for a couple months if it doesn't damage the ecu or anything else.

The first thing I read said they did it to theirs with no tune and it was a big improvement. After I bought them though I started reading more forums of other people saying differently. Idk what to believe.

Problem I'm having is it's been giving me issues with cranking up in the morning. I have to double prime to start. Then it died while doing 45 down the road about a month ago after driving for a couple hours. I couldn't restart it right away but then when I did and would give it gas, it would barely move and die again. So I replaced the pump and pressure regulator and it has not died again but I'm still having this same issue with the first start of the day. And double priming doesn't seem to help anymore.

KRUISR said:

I'm still lost on this statement. Why will you need to change to 19 lbs injectors?


You changed all this to try and alleviate double priming in the morning? Double prime to me would be the fuel pressure regulator (leaking by and bleeding off fuel pressure) or something like a clogged fuel filter or restricted line not allowing enough fuel to pass. Other things could be fuel pump (that you already replaced). Another could be a failing fuel pump relay - currently working intermittently.

Have you tried blowing out the fuel lines to see if any blockages?

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no, I changed all that over the last 6mo or so fixing other issues. Just giving yall the list so you know what isn't causing the problem. Replaced fuel filter about a yr ago and lines were good then. I'll try swapping the relay out next. Maybe another new filter? I still have enough parts to rebuild my stock injectors. Guess I'll pull them and try that too.

And I am planning on porting my intake and getting an upgraded head in the next month or 2 so figured I would need the 19lbs for that.

Mustang5L5 said:

You can’t just throw 19# injectors into a 2.3. I believe the 2.3 uses high impedance injector drivers and it will damage the ECU trying to drive the low impedance 19#ers.

You can correct this with resistors. I have no idea how many ohms will get the job done.

This is not going to correct your double pumping. Usually that’s a faulty fuel pump flow back issue or a bad fuel pressure regulator. Have you hooked up a guage and observed the trends with fuel pressure are you cycle the key and as the vehicle runs?

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These 19s are high impedance as well. I did an ohm test yesterday to be sure.
I have not hooked a pressure gauge up. Just been replacing everything until the problems go away but only because I want to replace everything anyways. I'm going to go through the whole fuel system again tomorrow. Haven't had a chance this weekend being called in to work every couple hours. People keep flooding their houses, keeping me from flooding my engine