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View Full Version : 80% throttle better then FT?



samishii
05-11-2009, 10:41 PM
When I accelerate down the road, lesser throttle (around) 7-8 PSI offers better acceleration then 10 PSI when in Full Throttle.... Ideas or suggestions?

Parker Dean
05-12-2009, 02:08 AM
Probably a bit on the lean side, starts detonating and the system pulls timing.

I suppose if it's running hot it could detonate and pull timing.

Gonna have to spend some time and do basic diagnostics first. Fuel [email protected], true operating temp, etc.

samishii
05-12-2009, 09:14 AM
Defiantly not running hot. If its running lean what possible causes are there?

Heres what I have done to the engine.
Cold air intake: 3in Alum tube with cone air filter.
Raised SC Lid
255 LPh Fuel pump.

Could it be injectors? Bad O2s? Too much air from the intake? :(

scxr7
05-12-2009, 12:31 PM
its not too much air from the intake. as long as you have your MAF hooked up correctly, and your MAP sensor hooked up correctly. it will monitor the air coming into intake. a lean problem could be a small vacuum leak or an air leak AFTER the MAF sensor. also, it could be from bad o2 sensors. if they are giving a false reading, it could cause the ecu to shorten the duty cycle of the injectors. could also be from a faulty fuel pressure regulator. or even a knock sensor. You need to hook a scanner up to your car and see what all the readings are. It could be a million things, you just have to narrow it down by process of elimination.

samishii
05-12-2009, 12:42 PM
What kinda scanner(s)? My SC is a 92... Wish I had OBDII ... Would love to be able to have a Tuner for it. Lol

Sorry I'm kinda new when it comes down to fixing things.

fturner
05-12-2009, 12:58 PM
its not too much air from the intake. as long as you have your MAF hooked up correctly, and your MAP sensor hooked up correctly. it will monitor the air coming into intake. a lean problem could be a small vacuum leak or an air leak AFTER the MAF sensor. also, it could be from bad o2 sensors. if they are giving a false reading, it could cause the ecu to shorten the duty cycle of the injectors. could also be from a faulty fuel pressure regulator. or even a knock sensor. You need to hook a scanner up to your car and see what all the readings are. It could be a million things, you just have to narrow it down by process of elimination.

We don't use a MAP sensor, only a BAP sensor since we're a MAF setup, so that won't be an issue in this case.

I'd be looking at things like a fuel filter, especially since you've got an upgraded fuel pump installed. Last time the MAF sensor was cleaned. Plugs and wires. The vacuum line that goes from the inlet tube after the MAF to the driver's side valve cover.

Your current mods are not going to cause the car to be maxed out in anyway, and in fact won't give anymore boost etc than what you had previously.

Fraser

samishii
05-12-2009, 02:07 PM
Your current mods are not going to cause the car to be maxed out in anyway, and in fact won't give anymore boost etc than what you had previously.

Fraser

I just mentioned the boost numbers because thats where I noticed them when I was running a couple of test runs. I don't want more boost at this time. I want my car to run right. Perf and upgrades come after fixing things. Even something this small. Cause if I have more power at less throttle. Then its not running right IMO.

fturner
05-12-2009, 02:17 PM
I just mentioned the boost numbers because thats where I noticed them when I was running a couple of test runs. I don't want more boost at this time. I want my car to run right. Perf and upgrades come after fixing things. Even something this small. Cause if I have more power at less throttle. Then its not running right IMO.

Thats a good plan to follow. I was just mentioning about boost as some folks think that what you've done adds power ;).

Fraser

NickM
05-12-2009, 10:14 PM
You mentioned a cold air intake.
Where is the MAF sensor in relation to any radii in the tubing?
Does it pull from the fender? If so, is the sensor right after a bend?

Nick

samishii
05-13-2009, 09:31 AM
http://i18.photobucket.com/albums/b142/samishi/th_DSCN3117.jpg (http://s18.photobucket.com/albums/b142/samishi/?action=view&current=DSCN3117.jpg)

>> Nick
The air filter, is immediatly connected to the MAF.

Yesterday I hooked up my 76mm MAF from SCP, and it made my bogging issue even worse. I even took some CRC Maf cleaner to the sensor. I could barely accelerate. I'm believing that its defiantly a fuel delivery issue now. Needless to say, its not on still. Gonna get a fuel-filter later.

kws6000
05-13-2009, 01:49 PM
Your hot air intake isnt going to help.

samishii
05-13-2009, 04:15 PM
Your hot air intake isnt going to help.

True.... But I'm waiting on a 85mm throttle body before I install my SCP cold air intake. Bought the adapters for it.

kws6000
05-13-2009, 06:51 PM
Hope you realize your 85mm tbody will do nothing as far as power is concerned and could result in coast down issues....SCP intake also wont do anything at this point.

scxr7
05-13-2009, 07:23 PM
check your TPS voltage. make sure its within specs. see what your fuel pressure is at.

you can use a scanner on an OBD1 car. they make adapters. They can show a data stream just like obd2. obd1 just doesn't have as many sensors and bs.

samishii
05-13-2009, 07:54 PM
check your TPS voltage. make sure its within specs. see what your fuel pressure is at.

Forgive me. I'm not up to date on the acronyms surrounding the various electronics of the bird. Sorry. =\

Sounds like a plan... Wish I could think of all this common diagnostic methods... I feel like an idiot. lol Guess that happens when your new to the game. :o

samishii
05-14-2009, 09:39 AM
I have some 42# injectors for my coupe, would there be any difference in installing those now? as opposed to when I get it tuned?

Would it be ok to install them, as they are clean, and I am worried about being leaned out an what not....

superbirdx
05-14-2009, 09:54 AM
I have some 42# injectors for my coupe, would there be any difference in installing those now? as opposed to when I get it tuned?

Would it be ok to install them, as they are clean, and I am worried about being leaned out an what not....

Is the 76mm MAF calibrated for the 42# injectors? If it is that is a good reason why it doesn't work right without them.
When it comes to doing mods everything has to work together. Most things by themself will usually cause a power loss. Larger MAF meters , throttlebodies and injectors are mods that don't equal more horsepower by themselves because they are mods to support increased airflow into the engine via a ported or aftermarket supercharger, intercooler and/or ported heads. A custom tune is also highly recommended.
Before all that you should spend lots of time using the search function and asking questions.
One mod at a time isn't going to do anything ,but, make things worse if you already have an issue with how it run's.

samishii
05-14-2009, 10:56 AM
The 76mm MAF will use stock electronics, and its currently not on the car.
I was just wondering if putting the 42# injectors on right now would make a difference. Cause I don't want to go buy new / used stock injectors when I have those, unless I absolutely have to (as I am currently un-employed).

I'm going to re-place the fuel filter this weekend. Hopefully I see some difference after.
Does the filter need any special tools to take off and put on?

:(

samishii
05-23-2009, 12:23 PM
bumping for hopeful help :(

DemonSC
05-23-2009, 01:21 PM
nope just a 8 or 10 mm to get the bracket off

samishii
05-25-2009, 09:43 AM
What about the filter's connection to the lines? I've seen my buddy use these little round plastic clamp looking peices to remove some filters, so I was curious.

Mike8675309
05-25-2009, 10:10 AM
What about the filter's connection to the lines? I've seen my buddy use these little round plastic clamp looking peices to remove some filters, so I was curious.

To remove the fuel line connections at the Rail, you need a special tool designed for "spring-loc" connections. But to do the fuel filter, the connections are different. At the fuel filter, the connectors push on and use a plastic clip that slips over filter ends to retain the push connectors on the filter. You'll understand better once you get under there.

You'll want to relieve fuel pressure at the rail. Then unbolt the filter from the chassis (under the passenger side floor, along the rail). Have a bucket ready to catch fuel that leaks out. Remove the plastic clips with a standard screw driver to pop them up. If any break, the filter box usually has at least one in it. If there are none in the box and you break one, you should stop and get a new clip before pulling the lines off. Auto parts stores will have replacement clips in their "Help" section.

With the clips removed, you can pull the connectors off the filter. It takes some effort to remove the connectors. Put the new fuel filter in place, making note of the arrow for direction of the fuel. the arrow needs to go forward. Push the connectors on far enough so the clips will fit behind the raised area on the line. Put the connectors on, bold the filter back up. And you're done.

XR7 Dave
05-25-2009, 12:57 PM
Actually, since his car is a 92 he will need the spring lock tools to remove the filter.

Note: It always helps to tell people what year your car is and what transmission is has and any other relevant info before asking questions and getting incorrect information from well meaning people..... :)

Mike8675309
05-25-2009, 01:45 PM
Hah, again the best way to get a right answer is to post a wrong one and someone will correct you.

I prefer these spring lock tools. I've used other types and found these the easiest to work with.

http://www.matcotools.com/ProductImages/ACD37.jpg