code 44 again

[rooferbret]

When I bought my 87 tbi jimmy it seemed to be low on power even with the 350 the po installed in place of the 305. I installed a new cat and flowmaster and it ran alot better Past cali smog test with flying colors.
Then code 44 lean exahst
replaced,
cap rotor plugs and wires
tbi to manifold gasket
all vaccume hoses
02 senser
fuel filter
My Wife drove to the coast and it ran great. same on the way home till She put fuel(3rd tank) then check engine light all the way home running like crap.
code 44 again I pulled the injector wires on the tbi one at a time,First one motor stumbled and died second one and the motor died instantly. So is this bad fuel or a bad injector? Any help would be great, Thanks Bret. /forums/images/graemlins/1zhelp.gif

 

[88Silverado]

You could have a fuel pump going bad or getting plugged. Did you pull the injectors and look to see if the screens are dirty?
Something is probably limiting fuel flow or pressure to the injectors. You can install a fuel pressure meter and check that.
Mine was the fuel filter. Looking at the gunk that came out of the inlet side, Im betting my tank/pump are going to have to come out soon for cleaning and replacement.

 

[4xcrazy]

I had the same problem with my '89 a few years back, kept getting that code, i also did the same thing, wires,cap,rotor,fuel pressure regulator,fuel filter,then i went even further and changed water temp sensor,map sensor,throttle position sensor,and there was one other one i can't remember the name right off, but all that crap and did nothing, finally after i drove on from San Diego, which is where i was stuck at, all the way home in 3rd gear because it wouldn't go fast enough or run good enough to go into OD. I checked out the fuel spray pattern coming out of the injectors and compared them to a friend of mines truck, same engine, and his was spraying alot more in quantity, so i went and replaced the fuel pump and it has been runnin awsome ever since. Sorry to have made this so long, but if you haven't changed that pump, and it has close to or more than 100k on it, i'd be willing to bet it's goin out. Weak pressure, can't get enough fuel, thuss lean exhaust.

Good luck. /forums/images/graemlins/waytogo.gif

 

[rooferbret]

The fuel pump was replaced 1 year ago. the thing idles like crap stumbles off the line and seems to run better the higher the rpm. I think I am going to pull the tbi and rebuild it. or try swapping the one of my wifes 89 silverado she blew the motor on last week

 

[88Silverado]

[ QUOTE ]
the thing idles like crap stumbles off the line and seems to run better the higher the rpm

[/ QUOTE ]
That sounds like a vacuum leak.
With fuel pressure it usually idles fine and is OK at low RPMs but dies out at higher.

You can take some carb cleaner or starter fluid and spray around the base of the TBI, hoses, manifold etc and listen for the RPM's to come up. If so, you got a leak.

 

[4xcrazy]

Yes i forgot to mention that too, it would idle fine, just no umph when you get on the throttle. I only stated all of what i did to give him some ideas as to what to check, but it is just about every sensor on it, so i guess take your pick.

 

[4xcrazy]

[ QUOTE ]
[ QUOTE ]
the thing idles like crap stumbles off the line and seems to run better the higher the rpm

[/ QUOTE ]
That sounds like a vacuum leak.
With fuel pressure it usually idles fine and is OK at low RPMs but dies out at higher.

You can take some carb cleaner or starter fluid and spray around the base of the TBI, hoses, manifold etc and listen for the RPM's to come up. If so, you got a leak.

[/ QUOTE ]

I was told that carb cleaner or starting fluid does not work well on TBI type setups, i was told to either use water or WD-40 as this will seal up the vacuum leak and then the idle will return to normal. /forums/images/graemlins/thinking.gif

 

[88Silverado]

Hummm...you know, you might be right. I have done that a thousand times on carbed engines never on TBI's.
I would be interested to hear other opinions on that.

Only other thing I can think of is a vacuum leak in the exhaust manifold or collector before the O2 sensor so colder/more air is getting in the exhaust. Maybe the AIR injector setup (if you have one) is stuck open.
Im guessing at this point.

Mine was a DOG. I could floor it from a stop and had little get-up and go. It would barely shift at WOT cuz the engine couldnt get up enough RPMs for the gov to shift the trans. Also made little difference when cruzing if I had the throttle partially cracked or 3/4. Seemed the same.
Again, that was fuel pressure.

Good Luck, let us know what you find /forums/images/graemlins/dunno.gif

 

[rooferbret]

Well I finally got to the jimmy. It started and idled ok so i tryed the wd-40 trick, no raise in rpm. Went around the block and was ok at first then as it warmed up it took more and more throtle to get going.So its of to kragen for a rebuild kit and regulater. Thanks for the help and I will let you know what happens. Bret

 

[spearchucker]

Before you buy crappy parts from Kragen, go to your local GM dealer and get some fuel injector cleaner, I think it's called 'Top End Cleaner'. Pour it in a full tank and see if that helps. Alot easier and cheaper than a rebuild kit. /forums/images/graemlins/thumb.gif

 

[rooferbret]

Fuel pump! /forums/images/graemlins/eek.gif Should have seen how black the filter in the tank was! Thank you for the help! Dropping the tank was not as bad as I thought it would be /forums/images/graemlins/waytogo.gif My jimmy has never run better! Thanks again! Bret.