Failure syndromes

[///Sniper535]

1. How do I know when my fuel pump is getting ready to go out?
2. When do I know when the starter is going to fail?

I'm about 182K miles and I feel like failure is around the corner.

[shogun]

there is no specific syndrom, a fuel pump can start making noise, get weaker or suddenly die, all possible.
I would recommend
a) when it comes to close 175 k miles and you need the car every day and drive long distances, better replace it or buy a new one at a bargain price chance and keep it in the trunk. Do NOT buy a used one or one which is out of the sealed and vacuum packed plastic bag, they have a big chance to never go to work again.

starter: just last Saturday we disassembled a starter from a 1988 750, same like on 3 more cases we found almost all of the inside made of plastic. Bosch changed that at a later day to metal. When you open it, all the parts fall out in pieces. This one also, see the pics
http://www.bimmerboard.com/forums/posts/643922/

so also here my recommendation, do NOT buy a used starter, buy a good quality reman one and keep it ready or change it now after 20 years.
Send in the old one as core and it will be cheaper.

BTW: anyone has a damaged motor starter for me as core? if possible from a E32 750 M70 engine, Bosch brand.

Popular mechanis says:

If there's anything over 60,000 miles on the odometer, but more commonly 100,000 plus, there's a good chance that the cause of this distressing no-start condition is an electric fuel pump that's no longer capable of forcing fuel forward with sufficient pressure. Even if the condition hasn't reached the point of grounding you, pump inadequa cies can cause numerous driveability problems, such as momentary cutting out, hesitation, low power and stalling at inopportune moments (typically, it'll start again after it's cooled off).

For years, the car companies have been looking for a pump life of 10,000 hours (say, 400K miles) as a bogey. Now, they're asking their O.E. suppliers for "life-of-car" (that many miles isn't a car's life span anymore?). To reach this goal, pump makers have lowered amperage draw and balanced armatures more precisely. That's all very admirable, but ask any service technician and he'll tell you that they simply don't last anywhere near that long in most cases. What's happening?

In a word, crud. Many (most?) of the fuel filters replaced are so jammed up you can't blow through them. If you had checked the pump's amperage draw before removing the old filter, you might have seen up to twice the expected number–perhaps eight to 10 instead of four to six. It shouldn't take much of a n intellectual leap to realize that a plugged fuel filter will make a pump work harder, and all that extra current will wipe out the brushes and groove the commutator, killing the pump prematurely. Also, the pump's already digested whatever's causing the restriction.

While on the subject of pump fatalities, another reason pumps burn out is because immersion in gasoline is necessary for cooling, yet people run around on "E." So, try to keep your tank at least half full.

Two-Legged Tripod?

For a century, mechanics have been taught that spark, compression and fuel are the legs of the tripod that support an engine's ability to run, and that's still true. So, before you jump to any unfor tunate conclusions about your fuel pump, do a spark check (a story for another day) and make sure the camshaft is still connected to the crankshaft (remove the oil filler cap and watch the cam or rockers while you have a helper crank the engine). If these two essentials are okay, you can start thinking gasoline.

Turn the key on and listen carefully. In most cars, you'll hear the pump run for a few seconds. No? Then check the fuse. If it's blown, and the car starts after you replace it, y ou should still find out how many amps it's being forced to carry. If pump electrical draw is too high, a fix now will head off a future breakdown.

You'll need either a low-reading analog ammeter or a DMM (Digital Multi-Meter) with suffi cient current-carrying capacity. Amperage testing is done either by hooking up the meter in series with the load, or with an inductive pickup that you clamp around the wire. The latter works best with big current flow, such as you'd find in the starter ci rcuit, so we prefer the former for diagnosing fuel pumps.

That means you've got to break into the circuit. Connect one of the ammeter's leads to the positive battery post and the other to the pump's hot wire. Look this up in a service ma nual or via your PM CD-ROM. Ditto for the specs, but we will say that if you see anything over 5 amps with a low- to mid-pressure system (13 to 45 psi), or 7 amps with a high-pressure version (60 psi) you've got a problem.

Will on-board diagnostics help you here? Not very often, although a problem in the pump relay circuit will set trouble code No. 42 on a typical Chrysler product, or code No. 87 on a garden-variety Ford.97
http://www.popularmechanics.com/how_to_central/automotive/1272391.html