Bad idle, loud fuel pump, no power

[VINCE325]

I have a 86 325

i just finished the car today and went to go get gas,
it was idling rough but it was drivable, as i started driving the car was feeling pretty good.
but on the way home the car took 5 tries to start and wouldnt make it up the hill( it just kept bogging down) i finaly made it up the hill but barley.
the car was knocking, and shaking and didnt sound to good
as kept driving home the car had like no power, i would give it gas and the car would start to bog down,
about after 5 minutes of tough driving the car started to feel better and i could accelerate better
and the fuel pump(on the drivers rear side) is making a high pitch whine

and i replaced the following when i bought the car:
timing belt
timing belt tensioner
water pump
thermostat
fuel pressure regulator
intake book
air filter
oil
oil filter
o2 sensor
idle control unit(used one)
ecu(used one)


any idea whats up?

[slo325i]

Mine's kind of doing the same thing.

The idle is alright but drives pretty good for the most part.

Issue with my car is that if gas is below the middle mark, the car won't rev more than 3500 rpms. The fuel pump is super loud as well. I think it's the fuel pump....

Let me know how yours goes after you replace that fuel pump. I just ordered mine...

Justin

[VINCE325]

ya, ok.
my car only has like 6 gallons in the tank, im gunna go back up to the junkyard and try to get one cheap

[Burnall4]

Whats the fuel pressure like? You said you replaced the regulator? (easiest way to test is to pop of the feed line and see how bad it shoots gas out <-- some say dumb idea but ehh, just don't have anything that can cause a fire near by...like spark plugs etc..)

If thats fine, I would say check the TPS and ICV and for any vacuum leaks...read my post several threads down, seems I have had all the complaints in this sub forum and have worked through a lot.

As for your fuel pump put an Ohm Meter on it...I don't have the bentley with me or I would tell you what the spec should be. Did you change the filter, mine was clogged up. hmmm, ideas?!?!

My 02 sensor was causing a lot of my rough idle, I still have a rough idle, but I am going through and changing parts, I bought a new ICV off a buddy of mine still in the box and it was bad, so I have to buy another one...test them out to make sure they are within spec before putting back on your car. Change the hoses for the ICV valve too...

What series is your ECU a 172? Did you reset the ECU at all, my car loved it when I unhooked the battery, pressed the brake pedal, and disconnected the ECU...(takes a lot of stored charge out of the car and lets the ECU reset)

[VINCE325]

i replaced the fuel filter and ill reset the ecu tomorrow

[jlevie]

That sounds very much like a dying fuel pump and/or a bad FPR. The full set of fuel system pressure and delivery tests is in the Bentley manual, but at the least you should tee-in a pressure gage at the inlet to the fuel rail and see what the fuel pressure is.

A used pump is pretty much a waste of time and effort, just get a new one. But before doing that, check the tank for a layer of rust in the bottom by removing the pump/sensor and stirring the bottom of the tank with a stick. If there is a layer of rust sediment in the tank you'll have to replace the tank (with a new unit) or acid clean and seal the tank. Rust is highly abrasive and unless it is properly dealt with the replacement pump will have a short life.

[Schniddy]

What series is your ECU a 172? Did you reset the ECU at all, my car loved it when I unhooked the battery, pressed the brake pedal, and disconnected the ECU...(takes a lot of stored charge out of the car and lets the ECU reset)

Wait, so you need/should to unhook your battery and press the brake pedal before you swap ECUs?

[jlevie]

All that's necessary to reset the DME is to disconnect the battery. There's nothing the car that stores charge.

[VINCE325]

problem=bad transfer pump(all rusty)

[416stroker]

For a cheaper fuel pum I would sugest summit racing they have an inline pump that's like $80. It puts out 80psi or somthing like that.

[pilotskillse30]

Okay so here is my add-on to this thread, I have an 93 cab(e30) and just yesterday it started to rough idle, it also seems to hesitate slightly if i'm driving and my rpm's are between 1900 and 2300, so should I be concerned and start looking into all mentioned in the above text.

[jlevie]

There are plenty of other things that will cause a rough idle and/or hesitation at lower rpm. Common candidates include:

1) Intake leaks
2) Incorrect valve adjustment
3) Bad plugs, wires, or rotor/cap
4) Aged O2 sensor (useful life is not more than 100k)

Those are all routine maintenance items that should be addressed first. Only if the problem persists after dealing with those should one begin to suspect the more esoteric causes.

[SamE30e]

Engine speed sensor or timing reference sensor, goes bad on 325's and causes retarded start up and bogging problems.