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it would be easier to sell....

Just replaced the fuel pump, which took care of 1/2 of my running problems. The car still hesitiates below 3200 rpms though. Last night I tested the TPS by unplugging it- it helped a bit, but not enough to make me think that it's the problem. Plugged it back in, and drove it home. Fiddled with the 2 front turn signals which don't blink I (the back ones do), couldn't find the problem, so I went to start it up to pull it into the garage, and now it won't start.
The engine turns over just fine, the fuel pump is working (I can feel gass in the lines) but it won't catch. I had started it up and drove it around not 5 minutes before, and previously it always started right up (the one thing it did well). Anyone have any ideas? Could I have unplugged something, or bumped some wire when unplugging the tps? Did I look at the car the wrong way?
Old 08-30-2005, 06:04 AM
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Well, I was mucking around w/ something under the hood once, and out of the corner of my eye I thought I saw a wire come loose. I looked carefully to confirm that it was indeed a broken wire and that I could relocate it, and then tried cranking - wouldn't catch at all. Re-connected the wire, and she ran good as ever. So, although I doubt it is the exact same wire, the point is that several of the sensors are absolutely critical. Although its tedious, its not totally unreasonable to read up in Haynes manual and locate each of the sensors on the engine and check that the (ancient, brittle) wires are all in good shape. If you're lucky it will be plain as day when you stumble upon it.
Old 08-30-2005, 11:12 AM
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Went through every wire in the engine compartment last night and everyone of them seems to be connected. With a voltmeeter, is there a way to make sure all of them are sending/receiving signals? I have one, but haven't used it except to test the batter, so I'm not sure what lead of the tester to place on the wire, etc...
Old 08-31-2005, 06:52 AM
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breathe, pause, think.
 
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If the voltmeter you have is a multimeter (you are able to switch it from reading volts to checking current--the ohm setting {the omega}) then you can test the conductivity of the wires. You might need an aligator clip w/ a long lead to extend the range of your multimeter wire leads.

You can test the battery in the multimeter by crossing the leads and observing the needle (or digital output) register a reading. Then just start connecting the aligator clip to the beginning and end of any particular wire you want to test for continuity/coductivity. You can also test sections of a wire by using a pin to poke through the insulation of a wire (providing its not too brittle), attach the aligator clip and just test that particular section.

Sorry, I don't know your experience level, so I'm might be describing things you already know how to do.
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Old 08-31-2005, 08:39 AM
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I'm novice as novice can get, so all help is appreciated :-)

Will start having fun with the multimeter tonight.... Another rookie question:

Could my timing and dwell be set up correctly, and the plugs (which are new) and distributer all in working order, yet have another wire from a sensor or something be the cause of it not starting? If the engine cranks, at that point it's either fuel or spark, right?
Old 08-31-2005, 09:15 AM
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roberj,

You can verify the front turn signal wiring by refering to this diagram. If your wiring is in accordance with this diagram and you still don't have front turn signals then I suspect that the BK/WH and the BK/GR wires on terminals L and R, respectively, on the back of the Emer. Flasher Switch are not connected.

Phil
Old 08-31-2005, 11:23 AM
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Quote:
switch it from reading volts to checking current--the ohm setting
The ohm setting is not for current, it's for resistance. Be careful when measuring current/amps.
Old 08-31-2005, 01:33 PM
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Thanks for all the help guys, it's much appreciated.
Measured the CHT sensor wire resistance all the way to the computer, and it was 3.2 oms, right where it should be I think. I guess that my 'car won't start' problem is somewhere else. Is there another lone wire that would keep it from starting up? It turns over just fine, just had the distributer and timing checked, I can feel gas in the lines- the fuel pump is new and pressure was set to spec. frustrating...
Old 09-02-2005, 07:10 AM
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Are you positive that you are getting fuel? Pull an injector to see if it is squirting. Be smart and squirt it into some fuel safe container not just on the engine.
Are you positive you are getting spark? Pull a plug and watch for it to spark. Be safe and dont spark it near the container of fuel.
If you are getting both pull off the distributer cap and bring the car to TDC #1 and look where the rotor points to. Is it close to the correct terminal?
If those 3 things are good try to start it after spraying some starting fluid into the intake after the buterfly.
Did it start? If so check your intake gaskest to be sure they are sealed up realy good. I ended up using some copper rtv with no gaskets to seal up my intakes. I have found the worst spot is between 1 and 2 o'clock and between 10 and 11 o'clock where the cooling tin is close and rubs the head between the two ports.
Hopefully by now the car starts and runs. If there is still hesitation in lower rpm's check all hoses for a good seal. Use clamps wherever you can.
If you still have issues with hesitation try another distributer. Yours may be worn and hitting the fuel injection triggers incorrectly and or the points.

I hope this helps.....
Nick
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Old 09-02-2005, 10:09 AM
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Good ideas. I would check spark before pulling an injector since it's easier (pull a plug wire off a plug, stick a spark plug into it, ground the threads, have someone crank it, watch the plug for spark.)

If it was running fine, then suddenly went dead and won't even try to fire, I would guess spark before fuel anyway.

If you pull an injector you'll probably need new seals before reinstalling. It's a good idea to replace them all anyway if they are old. I'm just thinking you wouldn't want to pull them out before having new seals on hand.
Old 09-02-2005, 10:47 AM
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Quote:
Originally posted by robertj
Measured the CHT sensor wire resistance all the way to the computer, and it was 3.2 oms, right where it should be I think.
3.2 ohms, or 3200 ohms? (3.2 Kohms) 3.2 ohms is way too low; the FI will think the engine is fully warmed up and will not inject enough fuel for a cold engine to start.

--DD
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Old 09-02-2005, 01:10 PM
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Dave,
School me here... if it is injecting enough fuel to run normally, but not quite enough for a cold start, wouldn't it at least get enough fuel to attempt to fire occasionally as it cranks?

I'm thinking back on what Robert said... it was running, then five minutes later it wouldn't fire. It wouldn't cool off enough to be dead that quick if it was a CHT would it?

Always learning...

Last edited by RandyLok; 09-02-2005 at 02:02 PM..
Old 09-02-2005, 01:59 PM
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Actually it was less then 5 minutes, I hadn't driven it around for more then about 15 minutes priort to it not starting, but would assume that it would have heated up enough not to qualify as a 'cold start'. no?

re: ohm reading, I think that although my multimeter read 3.2, the dial says either x100 or x1000 (don't have it in front of me as I'm here at work doing more important things like trying to fix a 914 ;-) will check when I get home.

Again, thanks to everyone for the ongoing help!

Last edited by robertj; 09-02-2005 at 03:05 PM..
Old 09-02-2005, 02:08 PM
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Ok, I checked and my ohm meeter reads 200k on the dial, and it's giving a 3.2 reading on the display from the CHT sensor to the end that plugs into the ECU. So does that mean 640,000? The mutlimeter when set to the omega 200k setting (there is no other omega setting) also reads 1 when the leads aren't touching anything, and 0 when they are touching each other. Don't know if this helps or confuses. (I know I'm confused...)

I also noticed that my ECU has the numbers 280-000-037 and 022-906-021E on it. I imagine this was installed when a previous owner removed the emissions and speed limiting stuff. Is this ECU fully compatible with a '75 2.0 car?


I have a feeling that if I keep poking around in this thing that I'm apt to find Jimmy Hoffa somewhere...

Last edited by robertj; 09-02-2005 at 05:28 PM..
Old 09-02-2005, 05:21 PM
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According to http://members.rennlist.com/pbanders/DJetParts.htm , your ECU is correct for a 73 1.7 or a 73 2.0 .

I think your meter is telling you 3.2 Kohms, which is a good number for a cold-ish head temp sensor.

I don't know if an overly-lean mixture would occasionally fire or not.

Anyway, the basics for an engine running are: Fuel, Air (compression), and Spark. Looks like you've checked that you have a spark when your car won't start. Check for fuel--you can stuff the injectors into glass jars, then have someone crank the starter while you watch them. Check that they squirt fuel, in reasonably equal quantities. Check that they have a spray pattern, not just a dribble.

Have you checked the compression?

After fuel, air, and spark, the only questions are "how much fuel" and "when is the spark happening". Check the timing as best you can--static timing should be close to TDC. Check the spark plugs to see what kind of mixture the car had when it was last running.

--DD
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Old 09-03-2005, 12:42 AM
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It's a miracle. I plugged in a spare relay board that I bought off of Ebay and ALL engine issues are gone. (I'm really jinxing myself here, I know...) The car started right up, and all the hesitation issues are GONE. No bucking, no sluggish under 3200rpms, just a smoooooth transition from 0 to as fast as I can go before I come to a red light. And it doesn't matter if I'm stomping on the gas, or barely pressing on the pedal, it's allllll good. Wow. Car runs better then when I bought it 3 months ago. Maybe it's time to look for new backup relay board (or have my old one re-done.) Amazing.


Again, a big thank you to everyone for ALL of the help, I'll have a questions or two about wheel bearings next I think (there's some play in the front whees when I grab them from the side of the car and pull/push back and forth- does that mean bad bearings?) But that can wait, I'm going to just enjoy a well running 914 for the rest of the weekend :-)
Old 09-03-2005, 01:42 PM
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.........robert robert robert. what the h3ll did i tell you at the swap meet when we started talking?! get a spare relay board!!!! see (read as I FREAKIN TOLD YOU SO). glad to hear your beast is finally on the road. these guys know there stuff....deeply, but there is no explaining the gremlins that surface from a bad relay board!
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Old 09-07-2005, 04:30 PM
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Heh, Don, I took your advice right after the swap meet and found one on Ebay. When I originally installed it however it didn't fix anything- but this was becuase I ended up having a bad fuel pump as well. So one problem was masking the other.

I was waiting for the "I told you so" to surface- What took you so long?!

Your advice was golden- thank you!
Old 09-08-2005, 08:12 AM
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