fuel pump

how do i know when my pump has gone bad? i made sure it had power and ground...anything else that needs to be connected? how can i test it? i have an 84 xj

also...how hard is the pump to change if i need to?

MonsterXJ said:

how do i know when my pump has gone bad? i made sure it had power and ground...anything else that needs to be connected? how can i test it? i have an 84 xj

also...how hard is the pump to change if i need to?

Click to expand...

Huh????

An '84 has a carburetor and a mechanical fuel pump. Has your XJ undergone an engine swap?

duhhh

oh no shit....:anon: sorry i havnt worked on a carburated engine in a while (i worked at a honda dealership for 2 years and now im at an acura dealership) so what else could it be? lord i hope its not a cloged filter, cause the guy who had it before me stripped the bolt and i cant get the damn thing off. any opinions?

It's easy to test a mechanical fuel pump. Step 1 -- remove air cleaner, cycle throttle linkage while looking down carn throat. If it squirts gas, there is fuel in the flaot bowl and the accelerator pump (not "fuel" pump) is functioning.

If no squirt, it could be that the accelerator pump in the carb is dried out, or it could mean no fuel in the flaot bowl. Disconnect line from pump into carb and put the end into a glass jar. Have someone crank the engine (or use a remote starter switch). If the fuel pump is good, gas will flow out of the line into the jar. It should be a strong flow -- if it just dribbles, could be a clogged filter or could be a bad pump.

yeah i just did that and i didnt get any fuel at all coming out, i know its not the filter cause i took that out, how hard is it to change the pump?

Before you rush out to buy a fuel pump -- is there gas in the tank, and is the line from the tank to the fuel pump intact and not kinked or crimped?

Changing the mechanical fuel pump is easy -- it's held into the block by two bolts. Since I don't know if you have a 2.5L or a 2.8L I can't tell you where to look for it -- there's so much emissions plumbing on the early XJs that probably finding it will be more difficult than changing it -- if a change is necessary.

Try jacking the rear of the vehicle up as high as possible, then test the pump again. If the tank is as high as the pump or higher, it should pump something even if it's failing. Many years ago I had one rupture the diaphragm badly enough that it filled the crankcase with gasoline, but it still pushed gas to the carb and the engine ran.