code 44

[sanddragon2004]

so i have this 90 burb just picked up.

has tbi 350.

surges at idle. and is running lean.

i pulled the codes and get

error code 44.

so far ive replaced the tps coolant temp sensor, fuel filter,

and throttle body gasket.

still does it.

new plugs new cap rotor. under the rotor looks rusty but not munged up.

hard to start and then surges when it runs. IM wondering if the 02 sensor might be bad.

when i rev it up it boggs and acts like its starving for fuel or maybe timing.

trying to figure out all the cheap stuff first before i start pulling fuel pumps an what not

anybody got any ideas?

 

[KohlTrain]

My book says, check ecm wiring connection terminals,check fuel pressure,check o2 sensor wire,check tb gasket,vaccum hoses and intake gasket for leaks,replace o2 sensor.

 

[dave w]

I'm wondering if the injectors are getting clogged up? I had a lean exhaust (code 44) because the engine was running with just one injector! Not enough fuel from the injectors will cause a lean exhaust.

dave w

 

[sanddragon2004]

injectors look good. and both flow evenly.

i am going to try checking the map, and all the grounds again.

o an does anybody know how to check fuel pressure on an efi motor?

 

[dave w]

o an does anybody know how to check fuel pressure on an efi motor?

It's not easy, but I've made up fuel fittings that allow a fuel pressure gauge to be connected down by the fuel filter. Some TBI systems use a piece of reinforced rubber hose by the fuel filter. Hope this helps?

dave w

 

[sanddragon2004]

replaced the map sensor.

still have the surging problem. checked grounds.

anybody know how to test fuel pressure on the tbi motor?

 

[Thunder]

I just fixed a Friends TBI truck with your same problem. Surging idle, bog on acceleration, no power, He thought it was fuel related. Intermittent CEL.
I Pulled the connections on the distributor module ( one seemed a little loose) cleaned them up. Plugged everything back in. Truck started up and ran fine after that. We did replace the distributor module just in case it was bad. With problems like yours the distributor module is usually the first thing i suspect. Loss of the distributor signal will shut off the fuel to the injectors.

To check fuel pressure you need a guage.
You can buy one like this:http://www.actron.com/product_detail.php?pid=16175
or
If you have a guage you can get an adapter.http://marine-performance-parts.com/cfmtechfuelpsiguageadaptorforgmtbi2843505774.aspx

 

[sanddragon2004]

5psi fuel pressure at the filter. Isnt that supposed to be alot higher? this truck has been sitting for a while. i figure that might have something to do with it. at least 6 months was full of dirt and dust so im figuring sitting in a field.

 

[dave w]

5psi fuel pressure at the filter. Isnt that supposed to be alot higher?

I usually measure 12 ~ 14 PSI at the filter.

dave w