anothadayridin

Ok guys i have some fuel pump issues. I've replaced. The fuel pump 3 times and still starts humming. After truck warns up and. If i punch the gas it will bog out n die I've nvr had this problem. And i don't. Know where to look replaced the filter also.


It is a 88 Cherokee. Laredo any advice. Would be apriciated

anothadayridin

Is This the fuel pump ground?

highmileage

check your fuel pump pressure(should be 35ish with the regulator hooked up and 40ish unhooked), and is your ballast resistor hooked up?
bogging down could be a MAP going bad or broken vac line to it, TPS going bad?

anothadayridin

Its a new engine. The pumps. Quiet until it warms it drives fine until warm. Then it boggs m backfires through. Intake while pumps. Buzzing. Through. The floor replaced. Tps twice map i swtchd i got spare stuff. Can't find any melted wires I'm about at a loss but my fuse panel. Did get wet about a year ago n my door locks quit wrkin. They do work on there own like intermittent. Locks and unlocks while driving.

anothadayridin

The resistor. Is hooked up new fuel filter also

Pelican

What brand of fuel pump?

anothadayridin

Only bosch

anothadayridin

Engine may have 10,000 miles on it. If lucky. But when cold it runs like a scolded. Dog

DFlintstone

OK. You need a meter, or a friend with one. Thinking you might have issues with "the lower" wires, (under the manifolds) or the IAT...anyway find a meter.

Start with Cruisers sensor ground test. (his "Pink Link", or find it in my signature) Then adjust the TPS. With the grounds checked,& good, you have a place to start from. THEN CHECK THE AC VOLTAGE OUT FROM YOUR CPS

Like highmileage said, and I pm'd you check the fuel pressure. If you changed the pump three times, that makes four pumps. Probably it's not the pump.

Check your Map tube;
There is a brittle little tube. It comes out of a rubber plug, low on the engine side of the throttle body. It runs back to the firewall, then up to your MAP sensor sort of high up there near center on the firewall. CRUCIAL!! The MAP will tell the ECU to dump fuel with less/no vacuum. Any crack or blockage and it will be pig-rich. (black smoke, fouled black plugs). You can pull the line off the MAP and feel for vacuum with your finger. If it runs!

Sort of dumb, but easy and maybe informative shot. Unplug both your IAT up on the manifold, and the Engine Coolant Temp sensor down under the manifold's and see if it still does it.

Renix will run on "default" settings until it warms a bit, then start using more sensors. (like the engine and incoming air temp sensors)

How is the idle? Does it "cycle" every 20-30 seconds?

So, there's that!

anothadayridin

Ok it is a h.o swap i did cruisers. Instructions. Yada yada yada lol i just. Checked the coolant. Temp wires the plug. Has melted. From the exhaust. Ist u talking. About the thing on the back of the intake. Would any of this cause the fuel pump to heat up n start buzzing. Alot

anothadayridin

Map is fine. Its got alot. Of vac

anothadayridin

The pump. Starts out fine then starts cutting. In and out of heavy buzzing. Until its always. Buzzing. Loud and vibing the floor


In the picture is that the pump ground

anothadayridin

I see none of the new post

anothadayridin

There are a few vacuum. Leaks. I can tell u that

I unplugged. The ist with no help/fix now onto the other

cruiser54

This help?