Running issue? (L05)

Got a question about my 1993 Caprice Classic Wagon 350 L05.

My family has come home for the holidays and I've been playing taxi. Well while in travels today she seems to run fine but when on a grade I can't go past half throttle it just kinda falls on its face and doesn't wanna go anywhere...

My recent things I've done were:

Cap & rotor

Plugs & wires

Coil

Removed cat

Installed a dyna max muffler (worst idea ever.)

Removed resonator

New fuel pump

Changed oil 1,500 miles ago. (Current mileage 149,017)

Fresh trans fluid and filter change 1,500 miles ago.

I don't as hell don't know what it could be....

Did you have something done to the wagon just before the problems began appearing?

Not recent no... Also the SES light comes on then shuts off after awhile

Perhaps a bad replacement coil. Dirty air filter? Pull the trouble code and see what it is. Could be a clue.

I don't know anyone with an OBD 1 reader... Which sucks...

You've got one in a drawer.

[You must be registered and logged in to see this image.]

[You must be registered and logged in to see this link.] And you don't even have to be named MacGyver.

[You must be registered and logged in to see this link.]

Can't you read the SES codes? You know, putting a "jumper wire" in the under dash treminal. I'll include a picture from the manual. Put a jumper wire in the A and B terminal to connect them. Switch the ignition in the on position, but don't start the engine. The SES light will flash code 12, one flash, followed by a short pause, than two more flashes in quick succession. This indicates that the system is working. After a longer pause, the code will repeat itself two more times. If no other codes have been stored, code 12 will continue to repeat itself until the jumper wire is disconected. A code is presented, i.e. by 3 flashes, a short pause and than 2 more flashes in quick succession. This is a trouble code 32. If you have no manual you could post the trouble code and i will look them up for you.

[You must be registered and logged in to see this link.]

Under dash terminal

I hope this is usefull, good luck,
Pete

Ok Greg, you where a lot quicker than me
Pete

I didn't see the mention of a fuel filter replacement. Change it if it has not been done recently.

Wow, never knew all that about our wagons on how to read our codes thanks guys!

gmtech, to be honest I would hope that its the problem I went out on bought a WIX fuel filter... Days like this in Pittsburgh I would love for a garage with heat lol...

So, what code did you pull.

EGR maybe? Hard to say without a code.

Welp I'm out here in the garage, I'm 44 as the code then 12...

I believe that code 44 represents a lean fuel trim. Code 12 is a "no fault" code.

I looked Olds Weighty Eight's chart, and its pointing towards an o2 sensor...

O2 reports an issue and is not necessarily the problem. But don't get me wrong here, they do go bad. A fault in the fuel system, among other things, can cause a lean condition.

You wouldn't replace the smoke detector in your home if it detected smoke, would you? It is only reporting the problem and making you alert to the condition. Do you fix the problem or replace the smoke detector?

Among other things, code 44 (lean exaust) suggest checking the PCM ground.
Pete

The PCM ground fault will also affect the O2 ground, and it will give you a rich reading. Been there done that.

I would replace the O2 sensor, because it is a cheap easy fix if it works. If it is not the O2 sensor, you have a good spare.

The only other items that could cause a lean mix are the fuel pump, injectors and the pressure regulator. Siince there are 2 injectors, and each runs one bank, it could only be the injector for the odd bank of cylinders, because there is only one O2 sensor, and it is on the odd bank. This would tend to eliminate the injectors. Worst case scenerio is to swap them.

Fuel pressure is difficult at best to check on TBI cars. The rebuild kit for the fuel pressure regulator is between $20 and $60 (you need one if you swap the injectors because you will destroy the gasket for the injector retainer). Fuel pumps are about $60+, and require a lot of work.

The fuel pump usually does not cause a lean reading even if it is beginning to fail. I have had 3 pumps fail, and never once had a code on any of them. I even had an intermediate pump hose split, and it did not throw a lean code. It allowed most of the fuel to flow directly back to the tank, and reduced pressure to the TBI...never a code.The symptoms for a split in tank intermediate hose were swooping idle, and iintermittant stalling/poor high speed performance. It also would let me sit occasionally, then suddenly decide to run normally. The split in the hose would open, and close depending on how the torque of the pump twisted the hose.

Uber long story short now 32 is coming up...

Time for an egr

Remove it, clean it. Re-install. See what happens.

Stingroo wrote:

Remove it, clean it. Re-install. See what happens.

Definitely going to try this first and see what happens...

Worked fine with mine when it was throwing EGR code.

Check the vacuum lines as well. Put a couple of drops of dishwashing liquid in a quart of water, and squirt it on the vacuum lines, and anywhere there might be a vacuum leak. If there is a leak, it will suck the water up. 32 usually means that the EGR valve is not working. It does not mean that it is open. The EGR should only open under steady state highway driving.

To make it more confusing, 32 is also the EGR soloniod. Just to be on the safe side, I replaced both the EGR and the soloniod when i had the code 32. Been running normal ever since.
Pete

[You must be registered and logged in to see this link.]

Certified PITA, but got it off with a little bit of finesse...

Cleaned it out seem to work for a bit then back to falling on its face...

As I'm sitting here in the wagon now I'm getting 44 and 32 still...

Plug the engine to actuator line for the EGR actuator solenoid, and see what happens. Clear your codes first.