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Old 03-13-2018, 11:38 AM   #1
G. Wiffington
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Injector Dead Times

Hey guys so I was surfing the web for information about Injector Dead Tmes. I came across this website that listed a wide range of different vehicle Injector Dead Times.


The list actually has Honda Preludes on it BUT...it lists "Honda Prelude 92-96 VTEC" with 330cc Injectors.

Over a bunch of threads on here I saw people saying the 93-95 H22's stock injectors were 345cc?

Why are there so many different ratings? I was pretty sure they are 345cc for the 93-95 USDM H22s?

Can anyone confirm 100% what they actually are?
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Old 03-13-2018, 01:29 PM   #2
G. Wiffington
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I found someone stating this information on Hondy-Tech:

Old 10-27-2014, 08:42 AM #23
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Default Re: JDM H22A injector size

I am not aware of the injector size being stated anywhere in the factory service manual. I own both a '95 and a '97 Prelude service manual... both are Helms Inc. factory service manuals. I looked in the specifications/service limits and the fuel system/injector sections and found nothing about flow rates. If you know where to find the information within the service manual, please share. I have quoted a size based off of tested data from RC Engineering, TWM and default menus within engine management systems when selecting injector types.

This thread seems to be nit-picking the size by 10-15cc +/- without stating a tested pressure as I did. The pressure matters, because if the operating pressure is lower than that in which the injector was tested/rated at, the flow will be LOWER. Conversely, if you run the injector at a higher pressure than it was tested/rated at, the flow will be HIGHER.

Let's use the 330cc injector at 43 psi as an example. The factory service manual states that the stock fuel pressure regulator has an operational range of between 33 and 40 psi of fuel pressure.

330cc @ 33psi fuel pressure = 287cc
330cc @ 40psi fuel pressure = 316cc

So, this means that the factory service manual is stating that an injector size of roughly 290cc to 315cc would work just fine in a H22A1 engine... assuming the fuel pressure was kept @ 40psi.

Fuel mapping by the stock ECU will be another matter when we consider the differences between peak-and-hold injectors and saturated injectors... in addition to ohm resistance. This is another discussion all together.
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