1992 injectors vs. '96-'97

[sspeedstreet]

Before my 1992 DOHC - Fiero swap was done I came across a NOS '96 fuel rail with injectors on eBay. I bought it and used the injectors on the motor. I can not get the engine to start (first start). I fires right up with ether, but acts like it's not getting fuel in the cylinders.

The plugs are firing.
The fuel rail has 42psi while cranking.
A scan shows the injector pulse at 31.8ms.

Will the 1992 ECM (9697) operate these injectors?

Also, should I be able to hear the injectors clicking with my head over the engine while cranking?

I really would appreciate any help you guys can give me.

Neil

[pocket-rocket]

I would try pulling the rail off the car and put it in a pan while cranking to see if they are opening up.

[robertisaar]

A scan shows the injector pulse at 61.8ms.

i'm not entirely sure on the cranking fuel requirements of the LQ1, but that seems like too much. i think the LH0 cranks at like 15ms...

[sspeedstreet]

i'm not entirely sure on the cranking fuel requirements of the LQ1, but that seems like too much. i think the LH0 cranks at like 15ms...

That was a typo. But still, it was 31.8ms, way above the 1-4ms the manual shows. 1-4ms is at operating temp and idling. I don't know what a value should be for cold cranking (61.0F).

[sspeedstreet]

I would try pulling the rail off the car and put it in a pan while cranking to see if they are opening up.

I resisted doing this until I had nowhere else to look.

Five dribbling injectors and one stuck open.

[bszopi]

Seven dribbling injectors and one stuck open.

I think your problem is that you have 8 injectors on a V6...

[pocket-rocket]

I think your problem is that you have 8 injectors on a V6...

2 for boost?

As a side note, you might want to give your oil the sniff test. That stuck open injector could have just trashed your oil.

[sspeedstreet]

As a side note, you might want to give your oil the sniff test. That stuck open injector could have just trashed your oil.

Yeah, it's draining right now.

The 6 injectors are at a local place getting cleaned and checked out. He was seriously skeptical old gas was the problem and only one had a little junk in the screen. I guess they weren't as "new" as advertised.

Neil

[sspeedstreet]

OK, now the plot thickens. I picked up the injectors from servicing this morning. The computer print-out says they're fine, like new. As we talked about it he mentioned something he found odd; he said he typically runs the flow test at 30psi, but these wouldn't operate at 30. He dialed the pressure down to 20psi and they worked fine! Now, as the rail is at 40 - 45psi, this doesn't sound right to me.

Anyone have some insight on this?

Thanks

[pocket-rocket]

Maybe what he uses to fire injectors wasn't giving them enough juice to force them open against the rail pressure.

See this posted:

http://60degreev6.com/forum/f97/home-made-fuel-injector-cleaning-machine-t42889/post403807

in this thread:

http://60degreev6.com/forum/f97/home-made-fuel-injector-cleaning-machine-t42889

[sspeedstreet]

Maybe what he uses to fire injectors wasn't giving them enough juice to force them open against the rail pressure.

Well, he's using a professional rig and it's what he does all day, so I have to give him the benefit of the doubt on that one.

[robertisaar]

those injectors shouldn't hydraulically lock at anything less than 43.5PSI, since that's what they run at from the factory.

[sspeedstreet]

I agree. A friend said he cleaned his injectors with a piece of fuel line attached, squirted some injector cleaner in the hose, hooked up 12V and used compressed air to blow it through. He suggested doing the same thing with the compressor set at 40psi and see if the tech is right.

[sspeedstreet]

It runs! The injectors seemed to be working so I bolted the rail down to the LIM and hit the starter. Ever see the movie "Grand Prix" with James Garner? That's what it sounded like without the UIM bolted on.

So after all this crap, the problem ended up being the set of ten year old never run injectors.

Just glad it finally ran.