 73 914 2.0l, Fouling plugs |
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| thon3720 |
 Mar 7 2008, 10:40 PM
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#1
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Newbie  Group: Members Posts: 1 Joined: 14-October 04 From: Bellingham, Wa Member No.: 2,951  |
I have a 73 2.0l with stock FI. I got the car after it has been sitting for about 10 yrs. After gettting it to run I changed the oil, cap, plug wires, plugs, and fuel filter. The car starts and runs every day but after 50-100 miles it starts to run rough and looses power. It still will start every day without trouble and idles fine. The only item the previous owner replaced that he thought was the problem was the pressure sensor. Any help would be appreciated.
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Replies(1 - 9)
| dw914er |
Mar 8 2008, 05:02 AM
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#2
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Planning Cities Group: Members Posts: 2,364 Joined: 1-March 08 From: Yucaipa, CA Member No.: 8,763 Region Association: Southern California |
mine will idle a bit rough (low) after it gets pretty warmed up, but that is because i have the fuel pump in the stock location, so it tends to suffer from vapor lock
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| ejm |
Mar 8 2008, 05:43 AM
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#3
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I can see the light at the end of the tunnel Group: Members Posts: 2,693 Joined: 3-February 03 From: Massachusetts Member No.: 224 Region Association: None |
QUOTE but after 50-100 miles it starts to run rough and looses power Could be fuel starvation. There is a screen in the bottom of the tank on the fuel outlet. Look throught the filler hole with a strong flashlight and see if there's a lot of sediment in the tank. QUOTE mine will idle a bit rough (low) after it gets pretty warmed up, but that is because i have the fuel pump in the stock location, so it tends to suffer from vapor lock Vapor lock causes hard starting because heat creates bubbles in the fuel. Your low idle is most likely something else. |
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| dflesburg |
Mar 8 2008, 06:12 AM
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#4
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Senior Member Group: Members Posts: 1,720 Joined: 6-April 04 From: Warm and Cheerful Centerville Ohio Member No.: 1,896 Region Association: None |
Have you tested your fuel pressure. Should be 28 psi but in hotter climates up to 31psi would be acceptable. Could be anything from weak pump, bad MPS or clogged filter.
good luck |
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| hi4head |
Mar 8 2008, 07:50 AM
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#5
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Member Group: Members Posts: 69 Joined: 4-April 06 From: Lexington, NC Member No.: 5,819 Region Association: None |
In the title to your note you mention "fouling plugs".
Have you taken them out and looked at them? How do they look and does each look similar? (i.e. wet, black and sooty, dry and brown, etc.) Chris |
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| 73Phoenix20 |
Mar 8 2008, 08:39 AM
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#6
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Member Group: Members Posts: 334 Joined: 15-June 05 From: Michiana Member No.: 4,283 |
Sounds like something is causing the "Brain" to go rich after warmup...
Cylinder Head Temp Sensor??? Manifold Air Pressure Sensor??? Check those out first.... |
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| Rand |
Mar 8 2008, 10:40 AM
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#7
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Cross Member Group: Members Posts: 7,409 Joined: 8-February 05 From: OR Member No.: 3,573 Region Association: None |
How would running rough and fouling plugs be caused by fuel starvation or low fuel pressure or bad pump or clogged fuel filter? Wouldn't those be more likely to cause a lean mixture? I would think the symptoms mentioned would be more likely to be caused by the opposite.
Rich mixture things to check would be: Does the MPS hold a vacuum? Is MPS vacuum hose in good shape and connected properly? Temp sensors good? CSV leaky? Fuel pressure too high? (over 30psi?) And Ben, I agree with Ed on the vapor lock issue. (IMG:style_emoticons/default/wink.gif) |
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| Jeffs9146 |
Mar 8 2008, 11:40 AM
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#8
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Ski Bum Group: Members Posts: 4,062 Joined: 10-January 03 From: Discovery Bay, Ca Member No.: 128 |
QUOTE Have you taken them out and looked at them? How do they look and does each look similar? (i.e. wet, black and sooty, dry and brown, etc.) (IMG:style_emoticons/default/agree.gif) Step #1 check the plugs Step #2 check the points Step #3 check the filters/screens Step #4 check vacume lines Step #5 check CHTS Step #6 keep checking stuff!! (IMG:style_emoticons/default/beer.gif) |
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| dw914er |
Mar 8 2008, 02:59 PM
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#9
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Planning Cities Group: Members Posts: 2,364 Joined: 1-March 08 From: Yucaipa, CA Member No.: 8,763 Region Association: Southern California |
ahh, yea, the hard start
i am thinking of recently, with my fi leak on the intake runners, those are causing that (dont worry, i am going to fix them next week when i am back in town) |
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| Rand |
Mar 8 2008, 03:05 PM
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#10
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Cross Member Group: Members Posts: 7,409 Joined: 8-February 05 From: OR Member No.: 3,573 Region Association: None |
To the original poster, thon3720: Your car sat ten years, and your symptoms aren't too bad - replace the rubber hoses that have deteriorated, starting with the MPS hose. And vacuum test that MPS. (Simple to do with a "mityvac" or such.... Just pull a vacuum on it and see if it holds.)
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