I'm running 55lb injectors and during idle car is smoking heavy and strong smell of fuel. Fuel pressure was set at 40psi/45psi with vac line off. Backed fuel pressure off 30psi/35psi vac line off and car stopped smoking but still smelling fuel. O2 readings were 489mv now 380mv on scanmaster. Do you think this fuel pressure will be alright? Any other ideas?
Engine smoking (Strong fuel smell)
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thewoodieb
Woodie
- Joined
- May 18, 2008
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Fuel Smell
I have a strong fuel smell also, it's related directly to fuel pressure, to much fuel not enough air or too weak of a spark. What was the main reason for the change of injectors? If you changed the injectors because of a larger turbo installation did you also change the plugs to a cooler rating? Granted this will not improve your fuel smell situation, but worsen it, thought it will keep your engine from grenading. Your increase of injector size is only allowing for more fuel to flow, you might try lowering reg pressure even more, all pressure does is increase the velocity of the fuel, your injectors control the delivery time and amount. The main reason most drivers increase the size of the injector is the satisfy the engines need for fuel(at high rpm or boost). Decrease pressure it will lower velocity and the "forced" fuel amount, but keep an eye on your scanmaster to keep a safe buffer. If the car drives fine then it could be your maf, mafs control fuel mix at idle, try swapping it out also. What color was your smoke, black indicates fuel, if your getting a bluish then chances are its oil. My car was pushing oil into my pcv overnight from crankcase pressure then it would get sucked in at startup and begin to smoke but would clear out after about 5-10 minutes, have you restarted the car since you altered the pressure to see if it still smokes? Hope I was any help.
I have a strong fuel smell also, it's related directly to fuel pressure, to much fuel not enough air or too weak of a spark. What was the main reason for the change of injectors? If you changed the injectors because of a larger turbo installation did you also change the plugs to a cooler rating? Granted this will not improve your fuel smell situation, but worsen it, thought it will keep your engine from grenading. Your increase of injector size is only allowing for more fuel to flow, you might try lowering reg pressure even more, all pressure does is increase the velocity of the fuel, your injectors control the delivery time and amount. The main reason most drivers increase the size of the injector is the satisfy the engines need for fuel(at high rpm or boost). Decrease pressure it will lower velocity and the "forced" fuel amount, but keep an eye on your scanmaster to keep a safe buffer. If the car drives fine then it could be your maf, mafs control fuel mix at idle, try swapping it out also. What color was your smoke, black indicates fuel, if your getting a bluish then chances are its oil. My car was pushing oil into my pcv overnight from crankcase pressure then it would get sucked in at startup and begin to smoke but would clear out after about 5-10 minutes, have you restarted the car since you altered the pressure to see if it still smokes? Hope I was any help.
Thnaks for the info. I think I may have some of the same issues you did.
Ok, I have cleared up the smoking problem. I adjusted the fuel pressure down and installed a breather on charcoal canister line that was once pluggrd off with a cap since canister removal.
chrisgarrett
Registered Member
- Joined
- Jun 2, 2004
- Messages
- 2,007
Fuel pressure is not an arbitrary thing; it's determined by the chip. You can't fix a problem by adjusting fuel pressure outside of the recommended pressure. Either your fpr is faulty, or you have another problem.
chrisgarrett
Registered Member
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- Jun 2, 2004
- Messages
- 2,007
Check your injector wires for shorts, especially #3. You could have a stuck injector.
- Joined
- May 28, 2001
- Messages
- 16,524
A few items:
1. The ecm does not control the FP. The regulator does.
2. Turning the FP down is NOT the way to correct a rich problem. Most injectors are rated at 3 bars, [43.5psi]. Unless the chip producer tells you to use another setting, the psi is 43.5, set w/ line off and plugged, engine running, warmed up.
3. If the vent line was plugged off @ the canister, that could be only part of the problem. Reducing FP is not part of the cure.[Refer to item 2].
Find the real problem. IE:
Restricted return line.
Improperly set tps.
Vac, intake air leaks, exh leaks. [Cracked headers, etc.]
Bad O2 sensor.
Bad inj.
Mismatch between the inj size and the chip specs.
Low battery voltage.
Poor ign voltage, due to "used up" coils/module.
EGR malfunction/leak.
1. The ecm does not control the FP. The regulator does.
2. Turning the FP down is NOT the way to correct a rich problem. Most injectors are rated at 3 bars, [43.5psi]. Unless the chip producer tells you to use another setting, the psi is 43.5, set w/ line off and plugged, engine running, warmed up.
3. If the vent line was plugged off @ the canister, that could be only part of the problem. Reducing FP is not part of the cure.[Refer to item 2].
Find the real problem
Restricted return line.
Improperly set tps.
Vac, intake air leaks, exh leaks. [Cracked headers, etc.]
Bad O2 sensor.
Bad inj
Mismatch between the inj size and the chip specs.
Low battery voltage.
Poor ign voltage, due to "used up" coils/module.
EGR malfunction/leak.
Thanks, Chuck I"ll look into these things
