I have intake manifold with 5th injector and want to replace with intake that has no 5th injector am I able to

Yes, and I have done precisely this on my own 1989 240. Do note that the style of the fuel injector retaining clips changed, so you will need to make certain that the replacement rail includes all 4 injector clips!

HOWEVER, if you live in a cold climate where the cold start injector actually gets used, you will want to check to see what ECU (fuel computer) your car has. 1989 cars came from the factory with computers that were prone to failure within a few years, and most have been replaced. Mine was replaced by the dealer in 1993 with a later computer intended for a car without the cold start injector.

john
--
1989 245 245K / 1993 945 131K

Get a 951 or white label 561 ECU if you do not have EGR.
Dan

...with the caveat that the 5xx series depend on the 5th injector while the 9xx do not.
--
Art Benstein near Baltimore

Birthdays are good for you. The more you have, the longer you live.

Correct, 951 is what you need unless you have EGR then look for a 933 or 946 which controls EGR.
Dan

The non-cold start injector manifold will fit on your motor--but if your fuel injection system was designed to use the CSI you will have difficulty getting started. Only systems that were designed to enrich the mixture on cold start-up at the cylinder injectors will work properly with that manifold. -- Dave

How do I know if it uses CSI.thanks for your info

"How do I know if it uses CSI"

If it came with a 5th injector...