When the car accelerates the butterfly opens to allow air into the intake manifold. In 1991 it switched to multiple port fuel injection and in 1993 moved.
Amc Straight 4 Engine Wikipedia
Jeep 2 5 4 0 throttle body measurement. The spacer is cutting off some airflow but like in 1 it is cooling the air resulting in an increase in horsepower. The tps is used to monitor the position of the throttle butterfly valve. 62mm bored oem throttle body for for 1996 2003 jeep wrangler cherokee and grand cherokee 40l bored to 62mm thru adds 35 more air flow over stock which necks down to 55mm newly remanufactured oem casting for perfect fit stock linkage iac and tps hookups may have minor pitting in throttle bore bench flow tested for stock idle air flow. I went to the junk yard and bought a thottle body off of a 40 for my 25. The engine used a carburetor until given throttle body fuel injection in 1986 except in the wrangler which switched in 1987. The throttle body is a direct swap you will need to switch out the 25 sensors to the 40 tb and get a new gasket otherwise it will bolt and connect up the same.
You can use a 91 04 throttle body but on the 96 you will have to cap the vacuum port at the base of the throttle body where the map sensor attaches on the newer jeeps. How to identify diagnose and clean all parts and sensors of a jeep 40l throttle body. The swap will get your butt dyno moving but not help our 25s. I just visually compared the two inside bores on the throttle bodies and it was obvious increase in the inside bore with the 40. The jeep 150 cubic inch four cylinder engine was introduced by amc in 1982 for the 1983 model year. Any way you could take a measurement.
The 25l manifold opening should match the 40l tb bore size. I thought the 40 was less than that bc the 62mm was an upgrade for it 1992 yj 25l engine mods40l tb ford design iii 19lb injectors firepower. 4 40l throttle body poweraid throttle body spacer and grind out intake opening 16 hp 27 more airflow. There are a few signs that could signal that the throttle position sensor. This same engine in the jeep cj models still used a carburetor. I dont know the measurement differences.
Size of 25 and 40 throttle body. This information is applicable for all fuel injected models of the j. The throttle position sensor tps is used in fuel injected and carbureted engines. Jeep thinks its a toyota. The yj wrangler application of the 25l introduced with the 1987 models came with tbi making this. 5 40l throttle body grinding out opening in poweraid spacer grinding out intake opening 24 hp 39 more airflow.
Tuning troubleshooting jeep 25l tbi four cylinder engines in 1986 the amc 25l150 four cylinder engine gained throttle body injection in the xj cherokee applications.