Bravada fuel injection problem - running rich, but why?

Hi,
My 94 Bravada has a strange (to me) problem. A month or so ago, the PCM
indicated code 32 - EGR valve. The idle was uneven and the car would
sometimes stall when stopped. I tested the EGR valve, the position
sensor resistance was slightly out of spec when the valve was closed, so
I replaced it. The code went away and the car ran fine after that.
Then, a couple of weeks later, it suddenly it started running extremely
rough on idle. Much worse than before. No check engine light. Low
vacuum, no brake boost. I suspected the booster was leaking. I
disconnected the vacuum hose and plugged it. Still very rough idle,
smoothes out at higher RPM. Next, I put a scope on the injector leads
and measured current. I saw the normal injector pulses running at the
same rate as the ignition, but also saw random narrow pulses between the
normal pulses. Any ideas what is going on? Is this a PCM problem? The
ignition looks good, no extra pulses there. The injector assy was
replaced under warranty a couple of years ago due to a leaking
regulator. The fuel pressure measures good and holds after the engine
is turned off, so the reg must still be good.

Thanks,

-- cb

Pull the EGR valve back off. You might have a piece of carbon holding
the valve open. There is a replacement gasket that has a screen in it.

In article .com>,
says...
> Pull the EGR valve back off. You might have a piece of carbon holding
> the valve open. There is a replacement gasket that has a screen in it.
>
>
Thanks for the quick response. I take it the gasket is a GM part?

--cb

In article >,
Chuck D. Bones > wrote:

> In article .com>,
> says...
> > Pull the EGR valve back off. You might have a piece of carbon holding
> > the valve open. There is a replacement gasket that has a screen in it.
> >
> >
> Thanks for the quick response. I take it the gasket is a GM part?
>
> --cb

No.

http://www.tomco-inc.com/

In article <nonelson-F418C6.00443215082006
@newsclstr02.news.prodigy.com>, says...
> In article >,
> Chuck D. Bones > wrote:
>
> > In article .com>,
> > says...
> > > Pull the EGR valve back off. You might have a piece of carbon holding
> > > the valve open. There is a replacement gasket that has a screen in it.
> > >
> > >
> > Thanks for the quick response. I take it the gasket is a GM part?
> >
> > --cb
>
> No.
>
> http://www.tomco-inc.com/
>
Excellent! I should have known about this sooner. Probably could have
avoided the purchase of that replacement EGR valve.

Thanks!!!

-- cb

In article >,
house says...
> In article <nonelson-F418C6.00443215082006
> @newsclstr02.news.prodigy.com>, says...
> > In article >,
> > Chuck D. Bones > wrote:
> >
> > > In article .com>,
> > > says...
> > > > Pull the EGR valve back off. You might have a piece of carbon holding
> > > > the valve open. There is a replacement gasket that has a screen in it.
> > > >
> > > >
> > > Thanks for the quick response. I take it the gasket is a GM part?
> > >
> > > --cb
> >
> > No.
> >
> > http://www.tomco-inc.com/
> >
> Excellent! I should have known about this sooner. Probably could have
> avoided the purchase of that replacement EGR valve.
>
> Thanks!!!
>
> -- cb
>
After searching far & wide for a Tomco dealer in my area, I found a
similar screened gasket made by Borg-Warner at Pep Boys. When I removed
the EGR valve, sure enough, there was a chunk of carbon the size of a
split pea stuck in the pintle. The valve is clear of carbon, the
screened gasket is in and 150 mi later the car still runs like a champ.

Many thanks to jfrancis & nonelson for the help.

-- cb