1.7 fuel injected won't keep started when hot, Runs great cold; won't hardly run when hot |
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1.7 fuel injected won't keep started when hot, Runs great cold; won't hardly run when hot |
dknechtly |
Oct 15 2017, 01:38 PM
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#1
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Yellow 914 Group: Members Posts: 68 Joined: 11-April 03 From: Wylie, TX Member No.: 560 Region Association: None |
Guys I'm stumped. My engine was recently rebuilt in the last couple years and I'm working out gremlins. 1.7 fuel injection runs and drives great but when it gets really hot ( I'm in Dallas area), it starts to run erratic. I have to pump the gas or keep it revved high to make it home. When trying to start it. I have to keep pumping the gas to keep it going. I have...
- fuel pressure about 28-29 lbs. - Bowlsby FI harness maybe 4 years old. - rebuilt Bolwsby MPS (I've switched out with others) and get no difference - swapped CPU's; no difference - swapped coil; no difference - new 914 rubber HTS; 2200 ohms cold @68 degrees; 118 when hot - FI points near zero resistance - no vacuum leaks - recent valve adjustments (a couple just to make sure) - fuel pump relocated to front for over 30 years - pretty new Pertronix ignition (the previous had failed after 10 years) Any ideas? Thanks |
dknechtly |
Oct 19 2017, 04:13 PM
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#2
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Yellow 914 Group: Members Posts: 68 Joined: 11-April 03 From: Wylie, TX Member No.: 560 Region Association: None |
Thanks for the replies. A further update. I found the engine dieseling (run on) after I turned it off. That usually means it is running lean. So, I turned up the knob on the ECU. That seems to have taken care of the hot start issue. I still get a little dieseling so I've added a little more resistance with an inline adjustable resistor. Still a little dieseling. Not sure what to try next. Maybe turn the fuel pressure up another pound?
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mgphoto |
Oct 19 2017, 05:07 PM
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#3
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"If there is a mistake it will find me" Group: Members Posts: 1,339 Joined: 1-April 09 From: Los Angeles, CA Member No.: 10,225 Region Association: Southern California |
Thanks for the replies. A further update. I found the engine dieseling (run on) after I turned it off. That usually means it is running lean. So, I turned up the knob on the ECU. That seems to have taken care of the hot start issue. I still get a little dieseling so I've added a little more resistance with an inline adjustable resistor. Still a little dieseling. Not sure what to try next. Maybe turn the fuel pressure up another pound? Run on should not happen with a fuel injected engine as pressure in the fuel ring drops immediately when pump stops and power is cut off to the injectors. |
nordfisch |
Oct 23 2017, 03:38 PM
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#4
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Member Group: Members Posts: 86 Joined: 11-December 15 From: Germany Member No.: 19,451 Region Association: None |
Thanks for the replies. A further update. I found the engine dieseling (run on) after I turned it off. That usually means it is running lean. So, I turned up the knob on the ECU. That seems to have taken care of the hot start issue. I still get a little dieseling so I've added a little more resistance with an inline adjustable resistor. Still a little dieseling. Not sure what to try next. Maybe turn the fuel pressure up another pound? Run on should not happen with a fuel injected engine as pressure in the fuel ring drops immediately when pump stops and power is cut off to the injectors. Hi, this is partly correct - and partly false: The fuel line holds most of the pressure for a <very> long time. Pressure gets lost only if the fuel-pressure line is leaking, pressure regulator or check valve are defective or the injectors are dropping. Check this. Maybe injectors are leaking. Regards Norbert |
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