So I swapped out my injectors with some of the Ford Racing four hole Bosch injectors, and swapped my throttle body with a 50mm throttle body. Also replaced the IAC, MAP, and TPS, all in an effort to figure out my slow start issue I've been having. Unhooked the battery while I did all this.

On that front, it worked great! Whole thing fired up immediately! But... Slight stumble, felt like a miss at idle.

Drove it around, nice responsiveness, impressive power even with the slight stumble... And then after about 15 miles, it throws a P0171 System Too Lean code.

Now, I figured that the new injectors were actually a little oversized compared to stock, but figured that the 50mm throttle would compensate. So the lean code was surprising. (Of course, it makes sense with the stumble that evens out with gas).

Before I installed the injectors, I replaced the filters and caps along with the O rings. I think I had two of them that were a little stuck, but hoped I was just imagining things.

So here's my question:

Can I run some injector cleaner through the fuel and drive it for a week and see if my stuck injector(s) will unstick? Or will that cause damage to the engine? Is there an injector cleaner you recommend?

I was really impressed with the improvement, even with the lean condition, so I'd rather not go back to the stock injectors if possible.

Options?

 

Is the 02 sensor on your truck still the original one ?, or is there more than 70 thousand miles on it ?. If the answer is yes to either one, its bad and needs to be replaced. Use an NTK or Denso 2 sensor, don`t use a Bosch 02 sensor, they don`t work well in our trucks.


Were the injectors you installed used ?, if so it might be a good idea to send them out and have them professionally cleaned and flow tested.


How much were the injectors, are they plug and play or do you need adaptors to make them work on our trucks. Do you have a part number or the vehicle that they came off of ?.


Thanks.

 

Nah, already thought of that. Both O2 sensors are NTK and less than 5,000 miles old.

 

Yep, used "ebay special" injectors. No adapters, plug-n-play EV6 Bosch 3 (mine is an 01 5.2), ford Motorsport yellows. Supposed to be "19lb" and from a working pull, but it's ebay, so you never know. That's why I'm guessing one or two are stuck/dirty/not flowing as well.

No make/model for the vehicle pulled from. I might decide tomorrow to pull them and put the stockers back on, then I'd have the injector number. Again though, really hoping some injector cleaner will clean them out so I don't have to send them off somewhere and give up some more coin. (Cause I'm cheap.)

 

Ohm check the injectors. If that's seems good, use some GOOD fuel injector cleaner, and see if it clears up.

 

Any recommendations on "good" injector cleaner?

 

2001 injectors are 21# I think. However, those ford inectors are rated at 39 PSI. I have the 24# injectors, and I had to get the duty cycle cut by 20% so it wasn't running at 8:1.

http://users.erols.com/srweiss/tableifc.htm
That can help for getting the right aftermarket injector. Without STOCK injectors you will be either running lean or rich until you get a wideband AF gauge and get a SCT tuner with custom tuning.

 

Right. The fords are at 19lbs at 43psi, which equates to 21lbs at our 49psi. I figured I should be fine there- no custom tuning required to cut back the duty cycle... Or so I hoped.

I'll tinker with it some more today, see if I can get it running a bit better.

 

Any gain you're noticing with the injector swap is likely placebo. The TB will be the only thing making any difference. I'd run the stockers

 

Yeah, I recalculated my figures, and the stockers are actually flowing 22.5lbs at 49psi, while the replacements are only flowing 20.3 at 49psi. That 10% difference (and apparently different impedance) isn't going to be compensated for by the PCM no matter how clean they are, so... Stockers went back on about 20mins ago. We'll see how it behaves this week.