2000 3.0 Flex Fuel Injectors Guidance Needed

[Gatorstick]

Happy New Year to All!!

2000 4x4 3.0 Flex (vin V) with 100k+ miles

Just started to misfire (#5) so I'm considering injector replacement. Searched the threads as to suggestions & didn't find anything definitive.

Questions:
Can vin U injectors (non Flex) be used without problems? I'm not going to use E-85. Some thread comments are yes, some no.

Has anyone that has done this switch able to comment as to issues or performance?

Any comments/suggestions as to replacement injectors? If you have replaced with "other than" OEM U code injectors, what's your opinion of your replacement? Any truth to Mustang V8 19lb injectors as a replacement?

Or........... should I simply just replace with OEM stock Flex injectors & be done with it?

last, Is it a pain to replace the injectors or are they fairly easy to reach once the intake is removed? (No need for great detail however if there is a trick to use, please share as I've saved much aggravation from many posts on this site.)

Your suggestions/comments are appreciated.

Once again, Happy New Year!!

 

[RonD]

It would run OK , but you would probably get a Check Engine light(CEL) because of injector dwell time.

I think gas only was 14lb injector and Flex was 20 or 22lb

You need a larger injector with methanol/ethanol because it has less energy per gallon than gasoline.
So you need more fuel added for the same amount of air
Gas uses 14 to 1, 14 parts air to 1 part gasoline
Ethanol is 9 to 1
Methanol is 6 to 1

This is why the flex fuel injectors are larger.
Dwell time is how long the computer opens the injector, computer then watches the O2 sensor for lean or rich.
If computer is "normally" opening injector for 20 with gasoline, and you switch to a smaller injector, the new dwell time may be 40, engine would run fine but computer would warn you that something isn't right, dwell is too long, so fuel pressure could be low, fuel sensor is wrong or......??
This assumes you have a fuel sensor, Ford dropped the fuel sensor on later models but not sure when.
If there is no fuel sensor then it would just think you are running E85, so no CEL

19lb might be close enough

 

[Gatorstick]

Ron,
Thanks for the info. Your comments don't sound overly positive for Mustang injectors......

 

[RonD]

Well the 19lb would be better than the 14lb for Flex Fuel

Bad injector is not a common issue for a misfire.
Since it is free to try you could test injector with OHM meter, should be about 14ohms, but test 3 injectors total, that will give you the average, 12-16ohms.

Also you can swap the #5 injector with another cylinder and see if misfire follows the injector or stays with #5.

More common misfire issues are spark plug and wire, and Coil Pack.
Reverse #5 and #1 wires on the coil pack and see if misfire moves to #1

3.0l also had a valve seat issue, lower compression caused the misfire.
So compression test would be a good test to do
All spark plugs removed
Throttle open

 

[stmitch]

It WILL NOT run right with different injectors. The PCM is expecting 23 ish lb flex fuel injectors, and will not be able to adjust to the 19lb regular fuel injectors (or any other size) without a custom tune.

 

[Gatorstick]

I'm going to do the tests as Don suggested, hopefully this week as I'm no where near sure the injectors are defective. At the miles the truck has, I figured it can't hurt to replace them. At present, I'm of the opinion to avoid a headache, it's wise to stick with OEM, engine appropriate injectors should I replace them.

 

[Gatorstick]

Ron,

Finally worked on the truck in Tuesday's balmy 70 degree weather.

With good compression across the cylinders, a replaced coil pack and swapping plug wires, I considered it might be a plug causing the problem. I replaced the Autolite platinum with 10k miles on them with Autolite Double Platinum. Truck seems to be back to itself again.

Thanks for your suggestions as they saved me a fair amount of time.

 

[stmitch]

Glad it seems better. Just an FYI, fancy platinum or double platinum plugs don't usually work well in the 3.0. Hopefully the new ones will last awhile, but next time you change plugs, try some plain Autolite or Motorcraft copper plugs. That's what typically works the best and lasts the longest for most 3.0 owners.