car won't start HELP!!

jb 924s red · 07-30-2003, 10:05 AM

Didn’t mean to start his way but…after changing a CV joint and putting on rear break pads took the car off the jacks and it will not crank. I have spark at the end of the wires (arc to frame test), fuel pressure on the rail (loosened cap on end of rail and fuel sprays out), all sensors that I can find are reading right or close airflow (voltage 4.3volts should be 8volts I think), airflow resistor (1.7K should be 1.45 to 3.3K), engine temp sensor (1.6K should be 1.45 to 3.3K) throttle switch (0 closed/infinity open) voltage to injectors (12volts engine not turning over / drops when engine turning over assume pulse) At my wits end, tested everything I can think of, according to Haynes manual. I was about to pull and clean injectors but how would I know if it worked if the thing won’t run.

Any and all suggestions will be helpful. Please

TCMdocs944 · 07-31-2003, 04:43 AM

Hey, I just a thought....

The car ran fine before the cv and brakes sooooo

What could you have possibly bumped in the process of that work?

I think no one has answered your post because you checked, properly, even the most complicated things. Has to be simple then.

Ground wire?..

TSNAPCRACKLEPOP · TSNAPCRACKLEPOP's Garage

is it an automatic, is it a stick? in neutral, or clutch depressed?? willnot crank....mmmmhhhmmmmm, posts on batt? i cannot help but smile when someone here works on their car in one area, then it will not go, in a seemingly unrelated area. geeeeshhhhhh, these are very similar to the opposite sex!~!

TSNAPCRACKLEPOP · TSNAPCRACKLEPOP's Garage

corr, neutral/park

AFJuvat · 07-31-2003, 06:19 AM

Wow, that was a complete, concise description of troubleshooting done thus far - Bravo!

On the other hand, you did neglect to mention what kind of car we are talking about - specifically the year (it does make a difference)

So, outstanding troubleshooting - 1 each "attaboy"
No mention of model\year - 1 each "aw*****"

Double check all cable connections (from the components you checked)
double check all connections in the vicinity of the transmission (make sure something isn't grounding out) The backup light switch and associated wiring is awfully close to the CV on the passenger side.

give us a few more details (model, year) and exactly what you were doing under the car.

Welcome to the group

AFJuvat

TSNAPCRACKLEPOP · TSNAPCRACKLEPOP's Garage

red 924s in headliner

TSNAPCRACKLEPOP · TSNAPCRACKLEPOP's Garage

is the battery dead from the door open and the radio blasing while you did the work?

jb 924s red · 07-31-2003, 10:34 AM

OK first, the car is a 1986 924S manual 5 speed. What was I doing under the car other than sweating to death in 100+ degree heat, 1) replaced passenger side CV, 2) replaced rear break pads both sides and 3) since it was on jacks when ahead and changed fuel filter. I changed the filter after it wouldn’t start and as a way to take a break from chancing the no start gremlins.

AFJuvat · 07-31-2003, 10:41 AM

Ok. my bad, didn't catch the car type in the name, revoke 1 aw*****

Check the wires around your transmission. - look for disconnected or broken wires.

AFJuvat

SoCal Driver · SoCal Driver's Garage

Check the wires on the fuel pump.

Add you car type and year and trans type to your signiture line.

ronin · 07-31-2003, 12:33 PM

that's what I was thinking since he was working back there in that area but he did say that he has fuel pressure at the rail

jb 924s red · 07-31-2003, 12:57 PM

I agree it has to be simple, but what… Last night I popped the distributor cap and cleaned the rotor and cap, checked again and spark to the plugs still good. I got the seals yesterday from the good folks from Pelican and using the procedure found here I will clean the injectors tonight I haven’t actually seen them spit fuel yet.

NickZaimis · 05:40 PM

seem's like you need to go back to the fuel filter area.
Or there is a air buble in the pressure line.
Unscrew few turns the fuel pressure line on the top of the rail.
Make sure there is no unscrew spark plugs around ...it will not be wise....turn the ignition key for couple seconds..
Good luck

asudds · 07-31-2003, 05:43 PM

I had the same thing happen to me after working on the car this winter... 1987 924S as well...

Turned out being an unplugged temp sender under the airbox/airflowmeter area. Check to be sure that one is plugged in as well as any others.

I was getting an extreme flooding condition.

jb 924s red · 08-01-2003, 07:02 AM

Worked on the car again last night, starting to pull and clean fuel injectors, during the process I discovered that the fuel pump isn’t running even though there is fuel under pressure on the fuel rail. The pump runs when I cheat the power to it so pump is good. Also discovered that there is no power on the hot side of the fuel pump fuse regardless of key position, off/run/start or anything. Now I have to find out what powers that fuse.

FYI apparently just having fuel under pressure on the rail isn’t enough, I haven’t measured pressure but assume there must be a sufficient amount to force the fuel through the injectors.

SoCal Driver · SoCal Driver's Garage

DME relay. It's always the DME relay.

jb 924s red · 08-01-2003, 07:57 AM

Looking in the manual it appears to go through a relay (the DME relay) and the O2 sensor, but the manual says that the sensor doesn’t come into play until the engines is at operating temp. So going back to the relay, where the heck is that thing. It should be in good shape again if I ever get it running again.

SoCal Driver · SoCal Driver's Garage

Fuse and relay block under the dash just above your left knee.

Has DME in big letters on the end.

jb 924s red · 08-01-2003, 08:06 AM

Thanks I will get upside down AGAIN, getting weak, dark closing in, to much blood to brain (not use to that whole blood brain circulation thing).

Know of any way to test this thing or which pins are which.

AFJuvat · 08-01-2003, 08:08 AM

Upper row, second relay from the left

AFJuvat