Too much fuel @ cranking - not enough fuel at idle!
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Too much fuel @ cranking - not enough fuel at idle!
Here is my problem...
I have the GReddy Ultimate and I'm trying to get my car tuned. It won't let you tune cranking fuel and idle fuel seperately [I think the tuner said it only gives you some preset type maps to work with?].
Using what we can...
The car has too much fuel to start and is flooded and if it does start it will idle OK.
The car has too little fuel, will crank and fire OK, but then dies because of lack of fuel.
Also, at around 5500RPMs there is a huge jolt, like the car bounces off the rev limiter or shifts very harshly [but its not doing either]. The entire car just shakes abruptly for 200 or so RPMs, the power goes down about 40hp and the RPMs drop straight down and then spike back up and continue on their "smooth" curve.
The shop told me to get a GReddy Pressure Sensor that will replace the MAF and that could fix the cranking / idling problem....The harness for the sensor is on back order for 6 weeks.
Anyone else got any ideas?
I have the GReddy Ultimate and I'm trying to get my car tuned. It won't let you tune cranking fuel and idle fuel seperately [I think the tuner said it only gives you some preset type maps to work with?].
Using what we can...
The car has too much fuel to start and is flooded and if it does start it will idle OK.
The car has too little fuel, will crank and fire OK, but then dies because of lack of fuel.
Also, at around 5500RPMs there is a huge jolt, like the car bounces off the rev limiter or shifts very harshly [but its not doing either]. The entire car just shakes abruptly for 200 or so RPMs, the power goes down about 40hp and the RPMs drop straight down and then spike back up and continue on their "smooth" curve.
The shop told me to get a GReddy Pressure Sensor that will replace the MAF and that could fix the cranking / idling problem....The harness for the sensor is on back order for 6 weeks.
Anyone else got any ideas?
2 Cars......2 Turbos...
Joined: Jun 2005
Posts: 1,235
Likes: 0
From: Dallas, Texas
What kind of boost controller are you running? I know the E-01 will let you mess wit hthe idle characteristics to an extent. The MAF my have carbon or some other build up in it preventing it from reading the amount of air properly causing it to lean out or add fuel. This was a problem in mine, we carefully cleaned everything and the idle characteristics corrected. What size injectors are you running? I have 660's and it takes some cranking to get the engine to turn over.
2 Cars......2 Turbos...
Joined: Jun 2005
Posts: 1,235
Likes: 0
From: Dallas, Texas
That is an odd problem with an SC....(I thought you were TT my bad.) It sounds to me like it's in the tuning. Something is going on with your E-manage ultimate. I'd say to look at your parameters again because to have a cut like that up top but no where else sounds like a fulel map problem.
If your running a return fuel system and bigger injectors . Starting has been a problem for most every one . Sharif can tell you more about it , but I think it has to do with fuel preasure being to high at start up . With the other problem , It could be some thing is off in the tune and your bouncing from one cell in the fuel map that has the right amount of fuel and another one that has very little
When my car was supercharged, with a return system, I would lose fuel pressure almost immediately after shutting the car off. So, I had to turn the car to the 'ON" position (so the fuel pump comes on) and then wait about 5 seconds. The car would typically start right up. I usually use the 5 seconds to put my seat belt on.
After the TT install I still have to do the same thing, as I still lose pressure with the car off.
I don't think you have a return system, so this shouldn't be an issue. I would have the tune looked at, or maybe even consider taking it somewhere else to tune it.
After the TT install I still have to do the same thing, as I still lose pressure with the car off.
I don't think you have a return system, so this shouldn't be an issue. I would have the tune looked at, or maybe even consider taking it somewhere else to tune it.
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2 Cars......2 Turbos...
Joined: Jun 2005
Posts: 1,235
Likes: 0
From: Dallas, Texas
+1 for low fuel pressure at start up. I do the exact same thing. there are a number of good reasons to let the car sit in the 'ON' position before you crank it over. With it in the 'ON' position it allows the battery to be on and current to flow through your electrical system which includes the ignition system and down to the spark plugs meaning when you turn the car over there is a better initial spark from all of the plugs. Additionally, with the battery on it starts your fuel pump and other electrical fuel devices in the car which will get the right fuel running through the lines with a full spark and it should crank right up. As for the dip at 5000 rpms I am going to agree with everyone else. That has to be in the tune.
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