Engine will not start.

[944slide]

My early 944 was working fine yesterday, but when I went to start it this morning, it would not start. The battery seems good, starter cranks the engine at proper rate, but no fire, not even a hint that is trying to fire. How should I go about diagnosing this problem? Thanks.

[lm6y]

Check the TDC sensor, and the RPM sensor. Do a search on this BBS, as it has been covered many times. This seems to be the year that they get cruddy, and fail to work right. Generally a good cleaning does the trick.

[PrerYDoG]

Put gas in it.

[kaffine krazed]

Check the basics first.

Do you have
gas
spark
fuel pressure
air
compression

[kukunaokala]

You can have all of those Krazed listed but, if you don't have timing it won't run either. Yeah, good advice, if it runs one day and the next kaput, do the basics.

Good luck and aloha, Neal

[944slide]

I pulled one of the spark plugs, cranked the engine, and no spark. I read the previous posts and a similar problem was traced to the DME control unit. I borrowed a DME from a friend, hooked it up, but still no go. Therefore I guess that is not the problem. How do I go about checking the TDC and RPM sensors? How do I check the coil?

Thanks.

[vas deferens]

try the DME relay, not the DME itself.....I wunder if your gett'in voltage at all to the DME as this would be the reason that your friends DME is not doin it fer ya!.......

[kukunaokala]

Believe it or not, a no start is one of the easiest problem to diagnose, getting it to run properly is where the bucks starts. If it's ignition, you'll need a basic knowledge of i=vr and multimeter or test light usage. Swapping parts is just guess work
and a bad habit.

Get a cold pack and make a friend with someone you would like to pick his/her brains with.

[Lawrence Coppari]

As Im6y said, check TDC and RPM sensor cables. Mine have connectors about a foot from the business end. They got cruddy/oxidized and would cause car to not start. By the way, ever since I put Stabilant 22A after cleaning with contact cleaner, my occasional hard starting has disappeared. It has been 3 months and car has never failed to start.'

If you take the sensors off, be careful. Don't ring off the bolts and don't drop the parts into the clutch housing. It has been done before.

[This message has been edited by Lawrence Coppari (edited 02-25-2001).]

[vas deferens]

Kukunaokala.........I tot da timing was regulated by "da kine" (the DME electronicaly)....if your not getting voltage to "da Kine" (the DME), then the next nearest component would be "da udda kine" (the DME relay)?........"Dis wood bee da firs ting" I that I would have checked with a low impedance light tester but I would rather use a DVOM as this would register in the mVolts and since your testing comptuer equipment low impedance would be da "ting" hea......jes pickin da noggin.......P.S.......no act eh?
I'm no kalole.....I can be akamai sometimes bruddah.........P.S. got any poi?....Kalua pig......loco moco?

[This message has been edited by vas deferens (edited 02-25-2001).]

[vas deferens]

Now for my non-pidgeon speaking friends,
I thought the timing was regulated by the DME and if your not getting the voltage to the DME due to a bad DMe realy, then how could you get timing in the first place?......This would ahve been the easiest thing for me to access and the first thing I would have looked at.......I would have hated to go thru the trouble of replacing another friends DME, frying it, and making an enemy out of him......anyway I was under the impression that you could measure the voltage from the relay to the DME to see if said voltage is being produced........vas deferens Non ASE certified master jackass

........Though I've been told by my ex-girlfriend.

[This message has been edited by vas deferens (edited 02-25-2001).]

[lm6y]

That name, and a sense of humor! Vas, you kill me!

[vas deferens]

IM6Y......your about the only one who gets the name.......some people thoght I was a German mechanic from Austria or something.....little do they know that it's the tubes that the Doctor snips on a vasectomy.........thus ......vas deferens...... it was either that or seminal vescicles.....which doesn't sound to germanlike.......you must have had an anatomy class sometime in your life....tootles

[lm6y]

How about seminiferous tubules? I was groomed in high school to become a doctor. But I came to the conclusion that I don't work well under pressure. So I figured that having someone's life in my hands, in an environment that I don't function well in, added up to a catastrophe waiting to happen. So now I "operate" on cars for fun. That's better than "recreational autopsies"!

[kukunaokala]

I "operate" on friend's cars for beer and pupus ( that's anything to eat with the brewskis though I prefer poke, raw fish and seaweed) and for future favors or pay off past ones.

Want to check sensors? Here goes, disconnect the sensor.Connect your multimeter ( digital not analog)leads to the sensor wires. Doesn't matter which prong. Set your meter to AC. Ground your coil wire. Have someone crank the engine. You should get some kind of signal, reading. The numbers don't matter, the main thing it goes from zero to something.

Since your car was running, I'd suspect something else. Getting to an '83's fuse/relay panel is a pain. I removed the steering wheel and seat so I could lay down on my back. I'm not as agile as I used to be.

Good luck and aloha, Neal

[vas deferens]

Ok Neal.........I remember having to work on a Toyota Camry with the vehicle speed sensor going..to test this, I raised the front wheels with a jack......attatched an analog meter (one with the needle)to the VSS and TDC sensor by using hte electircal jucntions in the engine compartment. I then spinned the wheels untill I see the needle move. This tells me that the voltage is being generated as the magnetic pick up on the sensors are passing each other......would that work in this case?......huh?........Huh?.......huh?.......vas deferens

[944slide]

Thanks for the help, and I'm going to need more. Progress so far:

1. I removed the distributer cap for a visual check, everything looks ok.

2. Bought a digital multimeter and checked the coil per the technique in the Haynes manual, terminal 1 to 15 (primary windings)reads 0.7 ohms, the spec is 0.4 to 0.6 ohms. Terminal 1 to 4 (secondary windings)did not produce a reading, spec is 5 to 7.2 K-ohms. I am not sure if the terminal 4 is corroded or if the secondary windings are bad.

3. Visual inspection of the wires, relays and fuses at the junction under the driver's side dash is unremarkable. None of the relays I thru XII is listed as a DME relay in the owner's manual. Where exactly is the DME relay located?

4. I have not been able to locate the cables for the TDC and RPM sensors. Can these be accessed from above, or do I have to put the car up on jackstands?

Thanks.

[lm6y]

The fuel pump relay is the DME relay I think.

The connectors are up top by the firewall for the sensors. Run a search on this BBS, someone has taken pictures of them, and they are posted there.

[palaxdad]

just to confuse you a little more... I have a 924 that had a similar problem. The car wouln't start on it's own but my mechanic could start it with his 'black box' that overrode the ignition system. I wound up replacing most of the ignition system and it still wouldn't start. The failure seemed to move from component to component. Finally found a broken wire at the coil. My mechanic jumped an existing wire coming from the back of the tach and it started... been fine for the last 6 months... ps. he also found out that his 'snap on' electronic diagnosing equipment does not work on Bosch which accounts for our bad ignition diagnosis.

[vas deferens]

palaxdad
good point to know.......I buy alot fo snap on and I shall investigate this further before I spend money on nothing that would do me any good.......I try to go with the basics and fancy tools really are for convenience and speed.......vas deferens