Early porsche 944 wont start..HELP!!
#46
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i tried the whole bangin on the sensors but no such luck. still testin and retestin yet trying to figure it out. my cap should be here tomarrrow thats the next thing to try. after this im pretty clueless except the DME. which i really hope it isnt.
Bryan
Bryan
#47
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A funny story. Once a friend of mine's car decided not to run. He replaced a million things and couldn't figure it out. Someone came up and said "you got gas in it?" and he chuckled and was like "OF COURSE, DUH!"
Long story short his gas gauge fuse blew and stuck on 1/4 tank.......... he was out of gas. Man was he ever pissed! He put gas in it and it fired right up. Well at least he had a bunch of new parts to drive around
If you have spark, then your car should be timing the ignition through the DME and sending the spark out. You have a new fuel pump, and I assume you have personally seen it shoot gas out the injectors? Also assume you have tested for fuel pressure at the injector?
Sounds like a sticky situation.
Long story short his gas gauge fuse blew and stuck on 1/4 tank.......... he was out of gas. Man was he ever pissed! He put gas in it and it fired right up. Well at least he had a bunch of new parts to drive around
If you have spark, then your car should be timing the ignition through the DME and sending the spark out. You have a new fuel pump, and I assume you have personally seen it shoot gas out the injectors? Also assume you have tested for fuel pressure at the injector?
Sounds like a sticky situation.
#48
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haha damn that sucks! no i kno there is at least some gas in mine. i have personally seen every injector spray fuel. checked fuel pressure which is fine. compression is fine. going to get a new cap tomarrow. then try a new coil even tho it tested ok. but yes i do have spark and fuel. spark is kinda small and doesnt really seem right so im going on that. i duno it was weird the car just stalled when i was driving it. all electrical worked just engine would start. it almost wants to start sumtiems when i bring the key to off after i started crankin it? ne ideas ne body???? thanks!!
Bryan
Bryan
#49
Defending the Border
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DAMNIT, this is one of the worst threads ever! Lots of great tips but no results.
Are there a couple of listers in the local area that could lend a hand? There must be a test result or two that are not being observed correctly. Fresh eyes see much.
Are there a couple of listers in the local area that could lend a hand? There must be a test result or two that are not being observed correctly. Fresh eyes see much.
#50
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haha well it taught me alot. sum stuff i didnt kno! i got a couple more things to try yet. if ne body is around the lehigh valley (eastern PA) area and would mind comin over n takin a look would be soo appreciated!!!thanks every 1 for their input. im not gunna give up on this!
Bryan
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#52
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sorry every 1 but still no luck got new cap and ignition switch and still nothing just sputters alot sumtimes but nothing more. kinda got fed up wit her and just let her sit till sum 1 came up wit sumthing new to try. thinkin about gettin rid of her even tho i really dont want too. but i dont have the money to take it to a garage or dealership because most garages quated me at more than 500$. but still ne input would be VERY helpful at this time. thanks everybody
Bryan
Bryan
#53
Three Wheelin'
for kicks try starting with removing one of the injectors and see if shell stay on...if she does u have a bad fuel pressure regulator...i know u said u have good pressure but it can also be too much pressure...thats what happened to me when she died all of a sudden
#54
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yup tried that already. i have spark at all plugs i have fuel at all injectors (seen them spray). just still very lost. spudders like it wants to start but nuthing. tried starting fluid. i tested the speed and refrence sensors and they tested fine to spec but would like to try new ones i guess..ne place good i could get them or nebody got ne good used ones?? almost out of money from all this and i lost my job cuz of this car. thanks!
Bryan
Bryan
#56
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Originally Posted by one
I hear you on cleaning them, but there is a known problem with the magnets sticking and not dropping back down to read the flywheel. A little tapping usually set's them straight. No dice?
The plastic bodies of the sensors will crack and break after many years of being in the very hot engine compartment. These cracks will eventually grow and cause the wires inside to break. Not only at the sensors but at their plugs too.
The rear sensor should be 0.8 mm from the top of the starter ring teeth. About the thickness of a dime.
As to this problem:
Go back through the testing procedure in this order;
With the key on check for battery voltage at the coil and at the injectors.
No voltage at the coil is a bad ignition switch.
Voltage at the coil but not at the injectors is a bad DME relay. The ignition switch turns on the first contacts in the DME relay which provide the voltage to the injectors and the DME. Note that the DME closes the second set of contacts for the fuel pump when the engine is cranking and after it's running. The fuel pump does not run with just the key on.
With voltage at both the coil and the injectors pull the plug wire at the front spark plug (#1), stick a spare plug in it, lay it on the intake manifold and crank the car. You should see a spark in relation to the rpm of the engine.
If no spark then check the wire from the coil to the cap. These will corrode inside the weather boots and pull loose when disturbed by changing the oil filter or getting caught on the headlight arm. Check that the rotor and cap are good and that the rotor has not come loose on the shaft. Check that the rotor turns when the engine is cranking. If not then the timing belt has broken.
Still no spark check that the sensors are connected. The plastic on these will crack and break sometimes breaking the wires inside. This can cause an intermintent connection. Beating on them will cause (further) damage to the plastic.
With spark check that the timing belt has not come loose and skipped teeth. This is as bad as a broken belt but harder to figure out as the engine may still sound and feel like it has compression. A broken timing belt will let the engine rotate freely and sound like a sewing machine. As may a seriously loose and skipped belt.
Check the connections at the AFS and the engine temp sender for the DME.
On the early 944's you can hotwire the fuel pump with an aligator tip jumper from aux fuse 2 to aux fuse 3. Count from the drivers door. Don't leave the jumper on as it will drain the battery.
You can hotwire the coil directly from the battery. This also closes the first contacts in the DME relay.
Other things that break:
The injector harness. The wires inside split off at crimped connectors. If you pinch the covering toward the fire wall you can feel these.
Solder joints and circuit paths in the DME. The DME has to be opened up to check these.
The plug to the DME. The wires break off of the pins inside the plug housing.
#57
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yeah i tested the sensors and they checked out ok. i did the whole .8mm thing didnt do anything. injectors fire and i have seen them cuz i took the rail off and watch each one spray when cranking. fuel pressure is fine compression is good at 175-180 accross all cylinders. i have spark and i have fuel. i took the black cover over the afm off and the doors moves while crankin if that helps. new ignition switch new cap and rotor new plugs ignition coil is fine. new dme relay fuel pump kicks on when cranking. dont kno about the dme temp switch?? the only thing i havnt done is the DME itself. nobody really had a 944 around here so i cant just swap it quick. checked all vacuum lines. alot of time it sputters liek it WANTS to start but it wont. tried starting fluid. plugs dont get wet after crankin awhile. ive checked the amount of fuel is supposed to come out of the rail in a 30 second time period. timing is perfectly on. lined up both tdc and cam. timing belt was just done not to long ago. cant figure it out??????? half a tank of gas in car. new fuel filter. it just died all asudded while i was driving around adn would not start again. i looked at the plastic around the sensors and no cracks or nething. cleaned all grounds in the fuse block and everything. ne other ideas? thanks
Bryan
Bryan
#59
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nah i seriously doubt it i had just filled up the day before it happened...then i also put another couple gallons in after it died just to make sure but still nuthin. and it wasnt raining very nice day out just cruisin and beatin on sum rice rockets...love doin that!! shes unbeleivably quick when she isnt bein alil b*tch lol
Bryan
Bryan