does anyone have any ideas i have a 88 ranger and it bogs down at 4000 rpms and when i give it gas it sounds very loud through the intake a lound sucking sound. I have replaced plugs,wires,cap,rotor,coil,coolant temp sensor,cleaned and tested injectors,cleaned egr,replaced fuel filter,cut off converter, checked all sensors. If anyone has any ideas it would be great. thanks

 

Which engine? You don't mention anything about checking the intake system. I would check to make sure that the problem isn't intake starvation. I would also check for vaccum leaks. The IAC can compensate for some, but the 88 uses a MAP sensor and SPEED DENSITY to adjust fuel mixture. Good luck and let us know how you make out.

 

IT IS A 2.3 LITER 4 CYL. WITH A 5 SPEED MANUAL. IT DOESN'T HAVE ANY VACCUM LEAKS THAT I KNOW OF. I TOOK OFF THE FULL INTAKE AND CHECK AND CLEANED IT AND IT LOOKS GOOD. I REPLACED THE MAP SENSOR AND THE IAC LOOKED GOOD.