Re: Starting problems Part 2

[brobertson@xxxx]

You're going to have to diagnose this step by step:

1) Ensure braided block to frame ground at passenger crossmember is
good. That's ONLY place starter, ignition, etc grounded (if car
stock). Many ills have been traced to that braid. Can check negative
battery cable too while down there (under passenger splash guard), but
it isn't exposed and should be OK.

2) Ensure fuel pump spins -- jump RPM relay (brown to white/purple,
opposite corners of harness connector). Pump should spin immediately.
If it doesn't check for voltage from fuse #7 and a good ground from
pump (fuse #7 doesn't pass through key switch BTW so can't leave relay
jumped forever).

3) Measure static battery voltage. Easiest from jump post in engine
compartment (also easiest for step 4). Needs to be 11+ volts.

4) Watch battery voltage as starter motor turns. If you're alone
simply run a wire from jump start post to solenoid trigger (white/red
I believe). If voltage drops precipitously battery is no good.

5) Measure voltage into coil. Must be at least 7-8 volts for coil to fire.

6) Check for spark as starter motor turns engine. Can either pull a
plug and lay it on block (lets you see quality of spark too) or simply
use a timing light.

7) Ensure injectors opening. If fuel distributor doesn't make
humming/moaning/whining noise as air sensor plate manually lowered
(RPM relay jumped), system isn't building enough fuel pressure. Can
pop injectors out to visually inspect spray pattern as air sensor
plate lowered.

8) Ensure no "catastrophic" vacuum leaks. Watch air sensor plate as
starter motor turns engine -- engine vacuum alone should lower 1/16 to
1/8 inches. 

9) Ensure spark advance diaphragm not receiving vaccum. Advanced
ignition timing much harder to start than retarded.

10) Ensure idle speed motor not stuck closed. If car starts by
manually opening throttle plates, is definitely something wrong with
idle motor, ECU, or microswitch.

11) Ensure cold start valve opens. Simply remove from cold start tube
and visually inspect spray pattern as starter motor turns. Engine
probably won't start with cold start tube open on top.

If NOTHING above works, will move to ignition timing, cylinder
compression, and clogged exhaust...

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, jettaman95@xxxx wrote:
> Dear List,
> A few days ago I wrote in saying that my car would not start. To be 
> more specific. The engine turns over like it is going to start. The 
> RPMs bounces up and down and I hear the engine like it may start. But 
> it dosen't.
> I just got a new battery and put it in yesterday. The car started 
> up with no problem. Then this morning I went out to start it and it 
> was a weak start noise. So I let my car charge all day and guess 
> what? It still is doing the same thing.
> By the way, while it was charging I checked each of the fuses to 
> see which was draining my battery. My cigar lighter was the problem 
> and I took out the fuse and the car still wont move.
> Please help!!
> Sincerly,
> Kramer
> ~10610