Won't start

smanna714 · 03-23-2010, 06:27 AM

I've been having issues with my 944 but it always started, just would take awhile.. Yesterday I had the dme coolant sensor unplugged and when to go start it and it started fine, idled but then it died out.. And now I can't get it to start at all. It has fuel/spark, so I don't get why all of a sudden it won't start.. Any ideas?

Paulyy · 03-23-2010, 07:01 AM

try fiddle with the coolant sensor plug, might not be in right or be dirty. if that sensor does even effect the engine

John_AZ · 03-23-2010, 07:34 AM

When you "unplugged the DME coolant sensor plug" and tried to start it.....

Did you just leave the bare copper tip dangling on the block and possibly shorted out the DME?

smanna714 · 03-23-2010, 10:15 AM

Nope, I may be dumb but not that dumb lol.. And I didnt recall it being bare it has that plug plastic cover around the connection prongs. I replaced the DME and MAF today and still no luck..You can hear/feel the engine like it wants to start but does not. When I check the plugs they are covered in gas and black.. I also replaced the speed/ref sensors. Spark is strong

smanna714 · 03-23-2010, 04:21 PM

Is there a way I can check the speed/ref sensors? I always thought if I was getting spark they are working

John_AZ · 03-23-2010, 04:27 PM

First check the tach on the dash, when you crank the engine does the needle bounce 1/16 of an inch. OK-then usually good.

OR
Speed and Reference Sensors - Checking, Replacement, and Adjustment

GL
John_AZ

smanna714 · 03-23-2010, 04:29 PM

It's an '83, was told they don't do the tac bounce?

John_AZ · 03-23-2010, 04:39 PM

???
I reread Clarks and no mention that an '83 was different in regards to the tach bounce.

smanna714 · 03-23-2010, 04:56 PM

Hmm ok I never noticed any tack bounce though even when the car ran

Vicious · 03-23-2010, 06:29 PM

i have a 83 as well, the tach will bounce noticeably when cranking. if yours doesnt try switching your reference sensor plugs on top you may have them backwards

smanna714 · 03-23-2010, 07:02 PM

Will do, would it start if they were backwards though? I never messed with the plugs and the car was just running few days ago

mikepellegrini · mikepellegrini's Garage

No it won't run if the speed sensor plug is plugged into the reference sensor, etc.

Vicious · 03-23-2010, 10:30 PM

yea lol scratch that idea, forgot if the sensors were switched it wouldnt start, if you need to replace one of them theres a bmw one that fits with same connection and all thats much cheaper than oem. or find a good used one

smanna714 · 03-24-2010, 04:36 AM

Do you know which BMW works? I'm going to a junk yard today and they are alittle more easier to find there than a Porsche lol

John_AZ · 03-24-2010, 05:25 AM

smanna714,

B4 U rush out and crawl over a few greasy shells, follow Clarks testing procedure for the sensors. Its a simple resistance check. It will also help at the junk yard to make sure you do not buy a dud with a no return policy.

Another suggestion is to take along the DME part number of your car and price a used in case you make a return trip. Usual price on eBay is about $100 +s/h. Maybe post a WTB (want to buy) on Pelican parts for sale forum.

But here are a couple of links that have the cross reference information:

Parts Cross Reference - Rennlist Discussion Forums

http://www.alanara.fi/Possu/ENosat.html

GL
John_AZ

smanna714 · 03-24-2010, 06:32 AM

Yeah I just got to the house now that the car is at so I'm gonna start the testing and post back what I find.. I totally forgot my tach STICKS, so that would be why I never see a bounce..Usually I have to slap the side of the dash in order for it to start moving.

smanna714 · 03-24-2010, 06:46 AM

Alright heres results..

Speed Sensor = 1016 Ohms

Ref Sensor = 955 Ohms

So I take it they are fine? Since Clarks says 600-1600 Ohms? Im stumped now and have no idea what the problem could be....I was hopeing it was these but now I have no clue, I work on this car everyday, atleast 4 hours a day and this is how it treats me

John_AZ · 03-24-2010, 09:34 AM

Just a couple of basic suggestions.

Is your battery up to a full charge with all the cranking you have done?
If you "slap" the tach now does it bounce at all when you grind the starter?
You said you have fuel and spark, did you try your spare DME relay or make a jumper per Clarks?

From the beginning, why did you work on the DME temp sensor? What problem were you trying to fix?

Clarks has a trouble shooting section:
Troubleshooting - Engine

balleysdad made up one as well. Includes many944s no start info:
Let start a NO START checklist

GL
John_AZ

smanna714 · 03-24-2010, 09:40 AM

Someone told me awhile ago to check the temp sensor. It tested bad thats why I replaced it..I just drained all the fuel out of it and it was brown and smelled nasty. I put new gas in but only about a gallon and a half. It seemed like it almost started but then it backfired thru the intake blowing the hose off.

I made a jumper relay and no difference, Battery is full was on the charger all night. Its only 3months old too

John_AZ · 03-24-2010, 09:54 AM

Fuel, because it was dirty brown looking.

If the tank was emptied, did you replace the fuel strainer in the tank? (where the outlet hose goes to the fuel pump)

Did you at least replace the fuel filter?

Do you have an injector NOID light to check if the DME is sending a signal to the injectors?

Your injectors should be DIY cleaned (see Tech Info Center above ^^) or sent away to WitchHunter Performance - Injector Cleaning & Flow Testing Services for cleaning.

.....a beginning