91 chevy tbi motor not runnig right.

[73chevytruck]

Well there wasn't a code for it but my oxygen sensor broke off. So gonna replace that and see if it fixes the problem. Egr valve was sticking to.

[Yetti]

couple things to check once you have the other stuff fixed.
1. coolant. it has to be set with a gauge so its at -35* . if its richer then that it won't pick up heat from the engine and it will read cold all the time making the engine run rich.

2. Thermostat. your year requires a 195* T stat. make sure it has one.

3 TBI base gasket. they can and will get sucked into the main run way under the TBI. when you took it apart did you find any gasket material stuck up inside the runners? they can plug ports in the body of the TBi and block functions to the egr.

4. as much as people say check wires & plugs most don't know how. I prefer the water test. I use a 2 liter pop bottle full of tap water. drill a 1/8" hole in the lid and squirt the wires and plugs down one at a time. if it stumbles and runs crappy you found where its leaking ignition juice. that makes a huge difference when chasing issues.

just remember the easiest stuff is almost always over looked. make a list on paper and check off every step you do. that way you aren't doing steps over costing you money.

[Colorado]

^^^^^ I'd just like to add that you can also clean out and fill a windex bottle with water and use that also in place of a 2 liter. Worked great for finding my cracked ign. coil.

[reaper1986]

I'd suggest checking the MAP sensor. It controls how much fuel the puter dumps in. Was the ICM replaced when you change the distributor ?

[xjs3667]

I had the same problem with my truck, change the fuel filter. I see u changed pump but not filter.

[73chevytruck]

Actually I did change the filter in the spring when I conveted the truck back to tbi. It was carb when I got it. After changing the o2 sensor it does run better but still not totaly right.