Have a 1993 toyota4x4 had new exhaust put on 2yrs ago just done plugs wires coil fuel pump an filter it runs good but when giving fuel from idle seems like it won’t take it but when I get going seem like it don’t want to take fuel but if I give it full throttle it take’s off then I have let off to stay at speed limit thanks

This sounds more like a stumble. You might look at the Throttle Position Sensor as it clues the PCM that you are changing the throttle position so it has to go a little richer and be in open loop. In addition go through the trouble shooting diagnostic tree for “stumble” or lean transition symptoms.

Dirty intake valves can also cause hesitation.

The carbon build up on the intake valves can act like a sponge and absorb some of the gas that’s suppose to go into the cylinders, causing a lean condition and hesitation.



Does it have a MAF sensor? Could be a dirty or failing MAF sensor causing this. You can clean it with MAF spray or simple Brake Cleen spray to clean off the element in the MAF…its kind of like a lightbulb filament that you will be cleaning. It is very fragile so be careful not to touch it…just spray it off. See if the situation improves. Also…try running the vehicle with the MAF unplugged…if it gets much worse you know the sensor is working…if it runs the same it has failed or is severely dirty. Just a thought and easy to check up on.