checking fuel injectors

spider2081 · Post by **spider2081** » Sun Jan 07, 2007 6:48 pm

I would like to check some Bosch fuel injectors. I put some fuel in them, then used a hand pressure pump to pressurized to 20lbs, Applied 12v and the fuel squirts out. When power is removed they do not leak. Is there a simple way to be more sure they will work if installed in the car?? I plan to clean them in an ultrasonic cleaner before trying them

So Cal Mark · Post by **So Cal Mark** » Sun Jan 07, 2007 10:37 pm

your test method is about as simple as it gets; power, ground and fuel. You'd need a test bench to check flow rates. The only other thing to look at is spray pattern

spider2081 · Post by **spider2081** » Sun Jan 07, 2007 11:13 pm

Mark,
Do you have any idea how long its safe to keep voltage on the injector?? I think in actual operation they are on for a short duration compared to their off time.

So Cal Mark · Post by **So Cal Mark** » Mon Jan 08, 2007 12:05 am

pulse width is short at idle and low speeds, but rises rapidly with engine speed. I seem to recall some figures of about 85% on-time on a turbo forum. The discussion was about determining when larger injectors were needed. As I recall it was felt that injectors wouldn't last when on longer than 90% for any length of time.
Hope that helps, but not sure if it answered your question

spider2081 · Post by **spider2081** » Mon Jan 08, 2007 10:41 pm

Thanks Mark, I was wondering if leaving the voltage on for like 1/2 a second would be a problem. I am pretty sure not but I will be quick. I have an extra rail so I will connect it to a pump and power one injector at a time and look at spray pattern on a piece of paper. I'll let you know what happens

So Cal Mark · Post by **So Cal Mark** » Mon Jan 08, 2007 11:56 pm

half a sec shouldn't be any problem at all

spider2081 · Post by **spider2081** » Mon Jan 22, 2007 10:35 pm

I think it worked satisfactory, With pressure on the rail no injectors leaked any fluid. When I applied power to an injector the fuel sprayed out. Pattern is a little hard to guage but appeared similar. The amp meter on the power suppply moved about the same for all the injectors.
Also found a universal injector seal kit at AutoZone that has the what I believe to be the correct upper and lower seals. Kit # is 90100

racydave · Post by **racydave** » Mon Jan 22, 2007 10:46 pm

We used to ck GM injectors with a ohm meter, they were between 8 to 13 ohms, not less.

So Cal Mark · Post by **So Cal Mark** » Mon Jan 22, 2007 11:27 pm

are the seals for Bosch injectors? If not, all of the Fiat vendors should have the right seals

spider2081 · Post by **spider2081** » Tue Jan 23, 2007 5:48 pm

The injector seal kit is a universal kit. Has lots of different seals in it. Some are "O" rings and for sure not correct. There are two sets of six seals the appear identical to the Bosch seals. One set is the larger seal that fits the outside of the injector. The other set is the smaller seal that fits on the ceramic. Visually comparing them to the old ones I removed, they look identical. I think its worth looking at. Cost for the kit is around $9.00. I am not an AutoZone fan just stumbled on it.

So Cal Mark · Post by **So Cal Mark** » Tue Jan 23, 2007 9:00 pm

that's a low price if the seals are the proper ones.

checking fuel injectors

checking fuel injectors

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