did crank reference sensors, now car won't start

Obin Robinson · 06-03-2002, 03:15 PM

i checked the gap of the sensors. i checked the wiring to the sensors. i'm getting fuel, and spark, the DME is fine.

car cranks, but won't start.

is there something i'm overlooking?

thanks!

obin

seb928s · 06-03-2002, 03:33 PM

Looks like I'm not the only one having trouble starting my engine. I did the rebuild on mine and the engine turns over but no spark or fuel; atleast you have spark and fuel

Britwrench · 06-03-2002, 03:44 PM

No, if you are getting fuel and spark the engine must fire....

Check that the reference and speed sensor are correctly connected.

Check the timing belt hasn't broken.

Double check you statement that you have spark and fuel pressure.

eligunn · 06-03-2002, 05:33 PM

try switching them even if you think you are absolutely sure they are routed correctly.

drew1 · 05:56 PM

Obin,

How did you check for fuel, with rail pulled & injectors still clipped in to watch spray in bottles? Maybe with the old cold crank problem the filter could be getting stopped up, regulator or pump going bad. Open the throttle body & spray some ether, then try cranking to get a quick idea if it is a fuel problem.

A 944 can make me wonder why I cussed a 924 CIS, sounds like you will agree.

drew1

edit: Wher did you check the fire, coil wire or plug wire? Bad rotor button?

Obin Robinson · 06-04-2002, 03:26 AM

Quote:

Originally posted by Britwrench
No, if you are getting fuel and spark the engine must fire....

Check that the reference and speed sensor are correctly connected.

Check the timing belt hasn't broken.

Double check you statement that you have spark and fuel pressure.

ok:

timing belt is fine (phew)
check the reference sensor AND speed sensor? hmm, possible that i unplugged speed sensor by mistake or knocked it loose? if the speed sensor is disconnected, will the engine not start? will that also cause problems with the tach? thanks!

i find it odd that all i did was replace the reference sensor and now the car wont' start. cranks like a champ but won't start

obin

seb928s · 06-04-2002, 06:45 AM

Yea it will not start without the sensors plugged in right. You can crank it all you want it will not start.

Obin Robinson · 06-04-2002, 06:47 AM

Quote:

Originally posted by seb928s
Yea it will not start without the sensors plugged in right. You can crank it all you want it will not start.

plugged in right as in plugged/bolted into that little bracket? or plugged in right as in plugged into the electrical connectors?

think i may have swapped wires by mistake and not noticed it?

thanks!

obin

seb928s · 06-04-2002, 06:55 AM

Check the connections and switch the plugs at the top and see what happens.

Obin Robinson · 06-04-2002, 07:00 AM

ok, i'll try that later. also...

the factory manual says that i can check the reference sensors with an oscilloscope to see if they get a 2 volt pulse. technically, wouldn't this mean i could check to see if i got a 2 volt AC wave using my DMM? it would just be a 2 volt AC square wave.

i'll check the connectors when i get home. anything else to think of? basically the only thing i messed with was the sensors.

thanks again!

obin

Obin Robinson · 06-05-2002, 04:28 AM

Quote:

Originally posted by seb928s
Check the connections and switch the plugs at the top and see what happens.

i cleaned the connectors and checked it out... car still won't start

this is puzzling. i only got one replacement sensor because i thought it was the rearmost one that was defective. could it be that the replacement was defective also? but why won't the car start after putting the original one back in?

thanks!

obin

ch944 · 06-05-2002, 05:17 PM

Did u get it running? I know what the specs call for as far as gapping but I just bottomed them out then raised them a hair and fired it up.

ch944

Obin Robinson · 06-05-2002, 06:50 PM

Quote:

Originally posted by seb928s
Yea it will not start without the sensors plugged in right. You can crank it all you want it will not start.

did i plug it in right? of COURSE i plugged it in right. i'd swear a months' pay.... i'd sign the title to my car on it. of course i plugged it in right... oh man, i think i busted the DME! don't tell me it's the timing belt... oh crap, the distributor is fried, no, it's the grounds, damn, the fuses are all.. wait, the DME realy.. no, i think i busted the...

wait, just a second... lemme switch those harness wires around.

oops!

yeah, that was it

funny how you KNOW you did something and you've got yourself convinced of it... and it turns out that it was something SO FREAKING SIMPLE in the first place.

point of reference, BEFORE you unplug these things ever in the future... put a bit of red electrical tape, or a twist tie, or mark each matching cable cable with a paint pen.

i can't freaking believe it was something so damn obvious and simple

thanks again guys! now the only test is to see if i can replicate the cold start problem (it's been like 82 degrees with high humidity).

i am going to take a few hours some day and go through every single electrical harness and ground cable in the 944. soemthing tells me that electrical issues are 90% of the quirks i am having, and have ever had

thanks again!

obin

drew1 · 06-06-2002, 07:28 PM

Obin,

Glad she fired up.

drew1

drew1 · 07-21-2002, 05:14 AM

obin,

I want the speed & reference sensor adjusting tool that I sent you sent back to me.

drew1

Leadfoot · 07-22-2002, 10:32 PM

hey obin, do you remember the picture you posted on your port and polish, how about sticking them up on your web site?? still having trouble getting them up, used to be able to view one of them now thats dissapeared too...cheers leadfoot, congrates on getting your car going again..

drew1 · 07-27-2002, 09:51 AM

Obin,

Tool came in. Thanks.

I appreciate the tips you gave, too.

drew1