Poor acceleration and rough idle cause?

[jrfinchen1]

I have a 1992 chevy k1500 350 TBI bone stock with almost exactly 150k on the odometer. I had this issue start to arise yesterday on my way to work, I was passing someone on the highway and I was going about 65 - 70 mph and I started to notice a speed shake or slight wobble Immediately. When I tried to accelerate more it would hesitate and roughly get there, when I stopped at a stop sign the engine wanted to bog down and quit. So after this issue, I stopped at the nearest gas station to check out the problem, I noticed when I have turned the key I wouldn't hear the electronic fuel pump engage and it wouldn't start after that. after I let it sit for about five minutes It started but I could tell the same issues it had a rough idle and sorta struggled to stay running so I limped it to O'Reilly's and bought a new fuel pump and filter to see if that could be the issue I put both in without little trouble and it started right up after that. It started idling nicely and didn't want to bog down but I still have the issue of a slight wobble and lack of power when trying to accelerate. Could it be the injectors? A spark issue? or could it be something completely different? Any help or feedback would be great. Thank you.

 

[PlayingWithTBI]

Could it be the injectors? A spark issue? or could it be something completely different? Any help or feedback would be great

Even though you replaced the fuel pump and filter, did you check your fuel pressure at idle and under load? It s/b 11-13 PSI. Your pressure regulator spring may be weak. Take a flashlight or timing light and shine it behind the injectors to see a nice even cone of spray at idle with no drips.

 

[jrfinchen1]

At idle there are slight drips I have noticed.

 

[PlayingWithTBI]

At idle there are slight drips I have noticed.

Then you'll need to rebuild it, your O-rings are probably leaking. Get a kit that comes with the pressure regulator diaphragm and find a 14LB spring since you're going into it.

 

[jrfinchen1]

OK, how hard is the TBI to rebuild?

 

[Ryno3]

They are not bad at all to rebuild, depending on how much time you spend cleaning it’s easy done under an hour. The tiny filters on the sides of the injector bodies are the worst part just due to the tiny size. Rock Auto has a kit for under $30, but it doesn’t come with the regulator spring, so be sure to order that as well. Mine came out in pieces.

 

[Schurkey]

Yes, verify fuel pressure. Should be no drips.

How old are all the usual "tune-up" parts--cap, rotor, plug wires, spark plugs, air filter? Does the thermostatic unit in the air cleaner snorkel work right? EGR functions properly? Timing is set properly, and the electronic advance works? Knock sensor works, and there's no excessive knock counts?

Connect a scan tool, verify all the sensors and computer outputs.