If your pushing the ponies with a Tune, especially if you've added a High Pressure Fuel Pump (HPFP), then you'll want to read more...
Lets get this part out of the way now because it's always the most frequently asked question for us.
We're at 82k and have tried 5 Tuners of which hands down we've had the best experience and results with ZFG Racing (Tuner) and XTreme-DI (fueling).
The life expectancy of a stock set of injectors is said to be anywhere from a life time to 100k miles of which BTW 100k is considered to be the numerical value of one average automotive life time. However, that's running a stock Tune and under average driving conditions.
Now if you've decided to Tune for e50 your still good with the stock HPFP and injectors however...if you're Tuning for e85 your going to demand a significantly higher fuel rail & injector pressure therefore, you'll need to install a HPFP. Your stock injectors will do just fine but you'll have to accept that you might only get half the life expectancy (50k) because you'll be working them harder with higher fuel pressure demands.
On that prelude note we will proceed with the point of the topic:
We've been performing R&D Tuning with stock Ford injectors over the past 2-3 years with great results however, after successfully Tuning for 87 & 93 octanes and e50 we moved on to e85. We installed the XTreme-DI HPFP in conjuction with the stock Ford injectors which proved to be very successful. While refining the e85 race Tune we finally began to experience injector sticking at 82k. So we went to our fueling sponsor (XTreme-DI) for a set of HiPo injectors but unfortunately they weren't going to have the set we needed for three months so we elected to proceed with another set of Ford stock injectors but of course after in depth cross referencing other higher preforming Ford injectors of which there were none we could be certain would be a direct replacement. So since the fueling demand was achievable and sustainable with the stock injectors we decided to accept the half life consequence for now. We also decided that once the XTreme-DI HiPo injector set came in we'd swap out the stock set since the job is much easier than it looks, as long as you adhere to the Factory Service Manual (FSM).
In summary the job is just a matter of detaching connectors and attachment points and simply manipulating wires and hoses out of the way, not removing, to facilitate intake manifold removal.
- You do not need to remove intake and charge air pipes, just disconnect them from the intake manifold attachment points to facilitate the intakes removal which is best done towards the passenger side of the car.
- The intake valves were surprisingly clean, equivalent to naturally asperated, given all the hype about coking on the back sides of the valves due to direct injection, however we suspect that installing the catch can at midlife may have contributed.
- We do not recommend refurbishing old injectors for HiPo applications
- We recommend replacing in sets due to batch Spec disparities
- New injectors come as a complete ready to install Assy, better than dealing with O-rings and directional retainers
- Recommend replacing intake gaskets (x6)
- Must use NEW injector clips to maintain proper tension on injectors
Here's some Pics: