I have a Blazer 92 4.3L TBI engine that runs OK except that thr engine runs rough at speed. It starts without any problem and idles OK.

But when you drive it hessitates at speed and misses a beat now and then. Even when running at steady speed it misses and it gets worse when accelerating.

I have so far changed the fuelfilter but that didn't do any difference. Sparkplugs are new.

I suspect some fuelproblem, could the TBI be clogged and how do I clean them if so?

Grateful for any tips.

Thanks


Jan

 

Check the spray pattern out of the injectors.

 

Having the same problem. My injectors seem fine, but i bought some injector filters($4 each). I had changed the ignition coil, but it made it worse. Changed the fuel filter, with better response and gas mileage. I also had changed the EGR valve, which made little change. I believe the problem is in the distributor. Either the module or pick-up. Really sucks buying parts that never fix it completely, but it is getting somewhere. Use a muiltimeter to check voltage at the coil. Auto Zone can test the module (free). Check wires for spark-jump. Check fuel pressure (11psi?). Most other sensor type problems would show a "check engine" light - get diagnostic key (free) or grounding device to check for codes. This should pretty much cover your ingnition, fuel, and pollution control. All this information from a $20 service manual and I'm still having problems, so good luck!

 

The problem was in the distributor, the rotor grounded to the distributor shaft. This was intermitent until it shorted fully and the engine died.


Jan

 

I will soon be looking under my distributor cap if i can only get a day off from work