Well I have noticed this cut since I got my car, I was never really sure what I went to. I just found out. I guess my car is supposed to have high impedance injectors, so the resistor box is not included and they just cutt the plug and heat shrinked it up.

I also hear that low impedance injectors have a tab centered on the injector itsself. High impedance injectors should have this tab off set.

Pictures speak for themselves.





I been fighting with a 'hesitation' problem now since I got the car, could this be causing it? I heard these injectors dont kick on (upper intake) until the primaries are at something like 75% duty cycle or 3800 RPM.

 

hesitation could easily be your fuel sock, check it out. Common problem is the tanks rust up, so the sock collects really bad. Worth a look if you never looked at it before.

 

That's definitely a low-impedence injector in the picture. Center tab = low imp. Do you know if all of your injectors are like that? If there are no resistors wired in-line under the hood or at the ECU, you've only got 2-3 ohms of resistance. The stock resistor pack has 6 ohm resistors, so you should have 8-9 ohms total. Too little resistance means increased current, which can damage the ECU & injectors.

I'd take a hard look at the injector wiring to make sure there are no aftermarket resistors wired in, and if not, see if there's any way you can hook the stock resistor pack back up. If it does have some, then it should be fine.

 

I havent had a chance to pull the upper to check the primary injectors yet, but the primaries are both definitely low IMP.

How can I tell if there is resistors in the harness? it doesnt looks like anything out of the ordinary in there.

Would it be just a plug and play to add in the resistor pack? Also, I changed my ECU to N326 cuz my ECU and pressure sensor were not the same code. Does it matter which ECU is hooked up (as far as using a resistor pack)?

My last question is, would this perhaps cause my hesitation?

 

In the first pic it looks like you just installed the injector. Did you just do a S5 intake swap? As for the second pic you can plug a resistor pack right in. That is a common doing for when a S4 low impedence is only avalible.

 

Resistors wired in-line will be obvious. They're not exactly small. Probably around 1.5" long and 0.5" wide.

I'm trying to figure out why your EM harness even has the plug for a the resistor pack. You info says you have an '88 vert, which means you should have had the high impedence EM harness and high impedence offset tab injectors. Someone has swapped your harness out with an older one, but also made the mistake of using low imp. injectors.

Your ECU and pressure sensor don't need to be the same code. N326, N327: no big deal (or N338 in the case of vert ECUs). All FC ECUs are the same in terms of how they work with the injectors. The resistance in the circuit is simply to reduce the amount of current the ECU sees.

And as far as hesitation, I know shifting the resistance level lower (but not too low) can help reduce the 3800 rpm hesitation, but in your case the resistance is far too low, so I'm not really sure. It's definitely something you want to fix, so you may luck out and find it fixes your problem.

 

Well then can I just plug a resistor pack in? Sounds too easy cuz you gotta play with the resistor pack to run high impedance injectors. I'm skeptical that I could just plug one in.

 

Like I said before, yes, if you don't already have resistors wired in.

LOW impedance injectors need the resistor pack.

HIGH impedance injectors do not.