Is the 2.9 SEFI, MFI or just regular EFI? OBDi Cylinder Balance test

[A4LD_Nghtme]

Hey there, I want to perform a cylinder balance test with my Innova OBDi reader but am not sure if the 1990 2.9 is SEFI or not. It says in the manual it's only for SEFI so I don't know whether I can perform this test or not. Please let me know if there's a way to do this test if it isn't. Thank You so much for any information!

 

[franklin2]

The 2.9 is batch fired, not sequential. You could unplug each injector and write down the rpm drop for each one. Less rpm drop means that cylinder wasn't contributing as much as the others.

I would think undoing each sparkplug wire would do the same thing?

 

[4x4prepper]

If you unplug the injector (no easy task) it does not inject gas and wash the cyl.

 

[SenorNoob]

Too old to do a balance test by computer.

As said you can use a tach, vacuum gauge, or trained ear (lol) and remove one spark plug wire at a time. Be careful though, they can bite. (Electrical shock. Potentially deadly so. I've never head a problems with my Fords for this. Did the 2.9 ever come with coil packs? If it did unplugging one spark plug wire cuts off 2 cylinders.

Probably the best way to estimate this on an older engine is compression testing each cylinder and recording the results.

 

[RonD]

Best way to tell if any engine has sequential fuel injection is to look at any 3 injector's wire colors
All will have the same Red wire
The 2nd wire at each will be a different color, if you see 2 of the same color out of 3 then it is NOT sequential EFI

Batch Fire was the common term for non-sequential EFI, on a V6, the computer opens 3 injectors each rotation then the other 3 on next rotation, and alternates every rotation
Odd and Even was the most common wiring, 1, 3, and 5 opened, then 2, 4 and 6 the next time