1984 944 No Start
04-07-2024, 09:06 AM
#1
1984 944 No Start
Hello beautiful people of Rennlist, long time lurker and first time poster here.
I have a 1984 944 that I have been daily driving (when it wasn't broken down...) for a little over two years. The car runs and drives great, when it starts...
The engine keeps on getting flooded and I'm not sure why. I have used spark plug testers on the spark plug wires and there is definitely spark. I attempted to do a fuel pressure test, but was unable to get the car started to complete the test. The fuel rail reads 40psi when I jumpered the DME relay, and seems to be holding pressure OK. All four fuel injectors have a good spray pattern and aren't clogged. I replaced the fuel pressure regulator to no avail.
I managed to get brief ignition when I tried to start the car with the gas pedal pressed about 50%. The couple of times I have been able to start the car, it runs perfectly fine once started. Most of the time though, the engine floods and hydro locks. Oh, also gas is getting into my oil (just did an oil change with cheap oil so I can continue my testing).
Any ideas or advice would be much appreciated!
I have a 1984 944 that I have been daily driving (when it wasn't broken down...) for a little over two years. The car runs and drives great, when it starts...
The engine keeps on getting flooded and I'm not sure why. I have used spark plug testers on the spark plug wires and there is definitely spark. I attempted to do a fuel pressure test, but was unable to get the car started to complete the test. The fuel rail reads 40psi when I jumpered the DME relay, and seems to be holding pressure OK. All four fuel injectors have a good spray pattern and aren't clogged. I replaced the fuel pressure regulator to no avail.
I managed to get brief ignition when I tried to start the car with the gas pedal pressed about 50%. The couple of times I have been able to start the car, it runs perfectly fine once started. Most of the time though, the engine floods and hydro locks. Oh, also gas is getting into my oil (just did an oil change with cheap oil so I can continue my testing).
Any ideas or advice would be much appreciated!
04-07-2024, 03:59 PM
#2
Definitely shouldn't be getting fuel into the oil. Must be running pretty rich so either a leak down test for injectors, does the rail hold pressure for an extended period of time? How's your amf? Could be sending a lean signal causing the dme to run injectors more. Bad O2 sensor maybe, IACV could be bad causing a lean run where dme is again running more fuel... Lot of people usually just respond with vacuum leak and clean grounds lol
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jrafferty (04-13-2024)
04-08-2024, 10:03 AM
#3
Three Wheelin'
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Gas probably made its way into the oil due to repeated long cranking of the engine and gas from the cylinder leaks past the rings into the crankcase, fouling the oil
Recommend closely reading and following the below guide:
https://www.clarks-garage.com/shop-manual/ts-01.htm
Recommend closely reading and following the below guide:
https://www.clarks-garage.com/shop-manual/ts-01.htm
Last edited by walfreyydo; 04-08-2024 at 10:04 AM.
The following 2 users liked this post by walfreyydo:
jrafferty (04-13-2024),
Northern944 (04-08-2024)
04-13-2024, 07:56 AM
#4
Thank you guys for replying to my post.
When I was testing the fuel spray pattern on the injectors, I noticed that the injectors were spraying fuel almost nonstop, with only very brief delays.
I bought new speed and reference sensors, so I'm going to replace those and see if anything happens.
My gut is telling me that there might be a problem with my DME, or perhaps the MAF sending a lean signal to the DME as Northern944 suggested. Any tips on how to test the DME and the MAF? I have a multimeter but I'm not very experienced with electrical work.
On a separate note, when I did an oil change, my old oil was actively boiling off the gasoline once it was out of the oil pan. Like, the oil drain pan was bubbling in 40F degree weather. would that be an indication of a bad oil pressure relief valve?
When I was testing the fuel spray pattern on the injectors, I noticed that the injectors were spraying fuel almost nonstop, with only very brief delays.
I bought new speed and reference sensors, so I'm going to replace those and see if anything happens.
My gut is telling me that there might be a problem with my DME, or perhaps the MAF sending a lean signal to the DME as Northern944 suggested. Any tips on how to test the DME and the MAF? I have a multimeter but I'm not very experienced with electrical work.
On a separate note, when I did an oil change, my old oil was actively boiling off the gasoline once it was out of the oil pan. Like, the oil drain pan was bubbling in 40F degree weather. would that be an indication of a bad oil pressure relief valve?
04-13-2024, 09:21 AM
#5
Thank you guys for replying to my post.
When I was testing the fuel spray pattern on the injectors, I noticed that the injectors were spraying fuel almost nonstop, with only very brief delays.
I bought new speed and reference sensors, so I'm going to replace those and see if anything happens.
My gut is telling me that there might be a problem with my DME, or perhaps the MAF sending a lean signal to the DME as Northern944 suggested. Any tips on how to test the DME and the MAF? I have a multimeter but I'm not very experienced with electrical work.
On a separate note, when I did an oil change, my old oil was actively boiling off the gasoline once it was out of the oil pan. Like, the oil drain pan was bubbling in 40F degree weather. would that be an indication of a bad oil pressure relief valve?
When I was testing the fuel spray pattern on the injectors, I noticed that the injectors were spraying fuel almost nonstop, with only very brief delays.
I bought new speed and reference sensors, so I'm going to replace those and see if anything happens.
My gut is telling me that there might be a problem with my DME, or perhaps the MAF sending a lean signal to the DME as Northern944 suggested. Any tips on how to test the DME and the MAF? I have a multimeter but I'm not very experienced with electrical work.
On a separate note, when I did an oil change, my old oil was actively boiling off the gasoline once it was out of the oil pan. Like, the oil drain pan was bubbling in 40F degree weather. would that be an indication of a bad oil pressure relief valve?
No problem, I always went to the forums for help initially.
Clark's garage
That link is to Clark's garage, 90% of diagnostic and how to on everything 944. Oil and fuel separate, so once exposed to air they separate and fuel evaporates quickly would be my guess. Oprv would be indicated by the oil pressure gauge. If you're doing long cranks you should be getting close to 5 bar psi. After it warms up it usually drops between 2-4 bar.
Does your car have an alarm? Did you bypass it? Did you bypass it correctly? Mine would actually run out of time and overly rich because I bypassed the alarm incorrectly on an early model 944.. weird I know
