1992 350 TBI problem

[denise 20352]

Maybe a fuel system problem.  As it warms up, when I give it the gas, it bogs.  It doesnt die, but it feels like it has died, because it doesnt accelerate.  The only way to get it going is to let off of it and let it slowly pick up some RPM.  The problem starts about thirty seconds after I first start it up cold.  As it gets a little warmer, it still bogs in the mid-throttle range, but if I floorboard it, it hesistates and then picks up and goes with plenty of power.  As it warms up to normal temperature, the problem almost goes away.  The idle is smooth, and top end is great.

I had the eletric fuel pump replaced a couple of years ago, replaced the coolant temp sensor and the ignition module.  It really feels like a fuel system problem.  Pumping the gas pedal has no effect.

The computer doesnt show any failure codes.  What should I throw at it next?  Many people would say a computer, but it doesnt seem likely, because the problem started after the vehicle sat for six months.

thx

-d

[George Woodford clc21025]

I had a very similar problem on an Oldsmoble Delta 88 (1977 Model).  It was the pich-up coil in the distributor.  As the car warmed to normal operating temperature, one of the wires would short.  It symptom was very consistent each and evey time.

[George Woodford clc21025]

Pick-up coil not pich-up coil.

[denise 20352]

I think I may have a bad oxygen sensor.

[Mike #19861]

 My first thought would have been a clogged fuel filter, but if you have lots of power on the top end, I doubt that.

 It almost sounds as if the timing is severly retarded. Have that checked. But keep in mind that it is possible for the balancers to slip on these engines, I have seen it many times. That will result in an erronous readiong. That will leave you to either replace the balancer, or time it by ear.

 Mike

[denise 20352]

Well, dad burnit.  I finally got a code from the computer, #13 which means that the oxygen sensor is bad, but replacing it didnt fix anything.  I guess I will look at this ignition stuff next.  Im buying a little cable thingie on Ebay that lets you plug a laptop into the computer and see what its doing, so hopefully that will give me a clue.

-denise

[Mike #19861]

 The O2 sensor only comes into play when the system goes closed loop. It will set a code if there is not enough activity from the sensor, ot it sets a consistently lean or rich signal. Often this is a result of another problem.

 But, O2 senswors should be replaced periodically anyway, but make sure you use an AC/Delco sensor. They seem to be the only ones with the longevity.

 Dont try to over analyse it. Cover the basics first. By elimination of potential problems there, you may save yourself a lot of grief and expense in the end.

 Mike

[denise 20352]

Its becoming obvious to me that there isnt any practical way to troubleshoot these things without the proper equipment.  The easy answer is just to stick with older vehicles, but since I already have a 1992 vehicle, Im going to suck it up and learn to use OBD1 with my laptop...for this one vehicle!  The biggest problem I have with newer cars is that they can fail totally without warning, which this one has.  It has ridden the tow truck three times in the past three years.

thanks

-d

[Bruce Reynolds # 18992]

Densie,

I wouldnt be surprised if the Auto Makers have shares in the large Towing Companies to off-set their losses.

They have share ownership in the Finance Industry.

Bruce,
The Tassie Devil(le),
60 CDV