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Registered
Join Date: Apr 2010
Posts: 35
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Someone correct me if I'm wrong....
So my '85 944 2.5 non-turbo still won't start, and I'm thinking the only thing left is the ECU. The problem is that when I put the DME relay into the fuse panel, the fuel pump doesn't start when the ignition is turned and there is no spark from the coil directly to a spark plug (I plugged the wire that goes to the distributer directly to a spark plug).
The car has tach bounce with ignition turned on. Both DME relays I have for the fuel pump check out according to clarks garage (bought another one thinking it was the problem, but they both were good apparently). The fuel pump does activate when using the three prong jumper. The engine cranks strong at start. Battery is new. The coil has current and checks out as good. All connections were tight (before I removed the ECU). That sound like an ECU problem? Please someone tell me it is, because I have no clue where else to look.... Thanks again for all the help everyone! |
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07-13-2010, 11:34 AM
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What would Darth Vader do
Join Date: Feb 2001
Location: Orange, California
Posts: 1,324
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Amphi, since you did not state where you are or if your car is an early or late 85. its a bit hard to help out. There is a recent commentary here about someone who had a problem similar to yours (within the last 3 weeks). His solution was to send it out for testing. He recd back a quick response from the vendor. ( Do a search in this forum) The other solution is to "borrow" one from someone who lives nearby, who has the same car as you, and plug that running unit into your car and look for a change (it runs or it doesn't).
Giving a little bit more info always helps here. Also, if you supply adult beverages and pizza, this helps spark interest, too..(Or diet pepsi in some cases) 
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1983 944 (2002 to now) 3-924's (Sold) 1967-912 (Traded) NEVER put a used water pump in your car... Last edited by Gordon Rankin; 07-15-2010 at 10:31 PM.. Reason: Hahahahahahahahahahahahahaha |
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07-15-2010, 10:28 PM
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Proprietoristicly Refined
Join Date: Jul 2001
Location: ~Carefree Highway~
Posts: 5,833
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Nice work so far. Early or late '85?
Check your grounds on the engine and all harness connections especially the AFM. Regap the sensors and check for resistance- Speed and Reference Sensors - Checking, Replacement, and Adjustment If you think it is the DME, you could check to see if a solder joint is bad. DME Repaired w/pics - Rennlist Discussion Forums OR Early DME repair write-up with pics. - Rennlist Discussion Forums Troubleshooting by the numbers: Troubleshooting - Engine OR Bennington Motorsports OR homegrown.. Let start a NO START checklist GL John
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1988 924S, 85,750K ..+ 1987 924S, 154K DD (+15K est. bad odo) |
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07-16-2010, 05:14 AM
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Registered
Join Date: Dec 2008
Location: Latrobe, PA
Posts: 407
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I had the same problem in my 924S....Mine was the fuel pressure regulator....try unplugging an injector from one cylinder and starting it. If it starts (obviously it will run rough) it's almost certain it is the FPR.
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'87 Guards Red 924S - First Porsche - SOLD 5/21/10 '67 Red VW Beetle - Restored by me and my dad, 2115cc motor. '87 951 - Silver/blk, full leather interior - LR Chips - 3 bar FPR - LBE '92 Ford F150 - Winter truck '04 Yamaha R6 |
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07-16-2010, 05:34 AM
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Registered
Join Date: Apr 2010
Posts: 35
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Thanks for everything so far, I bought the car with a cracked block and replaced the engine with an '84 (didn't mention that first time around, my apologies). I'm also not sure how to distinguish whether the car is an early or later '85 model. I ran the VIN through a decoder and it just said 85. Any hints on this?
Oh, and located in east Tennessee. |
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07-16-2010, 08:29 AM
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In the Fires of Hell.....
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Look at your interior: Is it late or early? That should tell you.
If yours is a late and you replaced the engine with an early, then make sure that you have the correct AFM for the computer. (late vs. early). Have you checked your plugs for fuel? Follow the checklists John posted...
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PCA Instructor: '88 951S - with LBE, Guru chips, 3Bar FPR, 1.3mm shimmed WG, 3120 lbs, 256 RWHP, 15 psig boost |
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07-16-2010, 08:59 AM
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Join Date: Apr 2010
Posts: 35
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From looking online, it appears my car is the early model (with the tach moving from right to left in a "U" shaped swing vs. left to right on top of the tach). I would assume that means the ECU and AFM are correct for an '84 engine?
And John, thanks for the links, that is some great info. Now if I could only muster up the cajones to open the ECU and break out the soldering iron... |
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07-17-2010, 07:50 AM
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One apex at a time
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Do you have three seperate gadges Like this
Early Dash (pre 85.5)  Or does the dash look like this (post 85.5) 
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07-17-2010, 03:51 PM
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Registered
Join Date: Apr 2010
Posts: 35
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Thanks for the pictures Dean, those confirm that my car is the earlier (pre 85.5) model.
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07-19-2010, 02:11 PM
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Registered
Join Date: Apr 2010
Posts: 35
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  From the inside of the ECU does that look normal with the discoloration? It does smell like it has been hot at one point, but the internal components look normal (no charring or burn marks). I will say when I was going through the fuses, I did find a fuse that the PO had soldered back together (I really have to take a picture of it and post it here...). Can't remember which fuse it was, but it was white and I think that is an 8 amp fuse. What do you guys think? Whether its fried or not, I'm about certain I will be buying an ECU very soon. Once again, thanks for all the help. |
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07-19-2010, 06:11 PM
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944 Turbo
