IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Buick Tech => Topic started by: TurboCajun on October 20 2013, 08:17:59 PM
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I ran better at 18 psi 11.37@118 in april i think i was but is was alot cooler.
I noticed on pass three that my tps was over 4.8 at some point which it should not be , I will have to adjust it.
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I MPH are way off from the time slip
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You need to tell us if you are running a wideband, and what kinda maf plus if this is an alky car, straight race gas, or what....
Looks rich in first gear which slowed the power some and was too lean on top end which was causing timing retard and dinging the head gaskets
Do you have a fuel pressure gauge on the car so you can tell if the pump is keeping up with boost properly
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All kinds of KR...possibly because your volts are low.
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no wide band, translator w/ impala SS maf, 93oct with alky, I dont have a FP gauge on the car but I did check it line off before i made my first pass
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sometimes, you all make me want to cry
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why is that Steve?
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Because one of the most basic things required to know that the car is working properly is the fuel pressure at wot at the top of third gear. If it is dropping, or staying constant, instead of tracking boost, you are going to blow something up sooner, rather than later.
A rail mounted gauge is useless. First they usually quit reading properly very quickly-if they ever read right. Second, they do nothing to tell you how the pump performs under load or if there may be a problem with the pump, the wiring, the hoses, or the fuel pressure regulator.
I can set fuel pressure looking at the O2s with the hose on but I cannot know what the pressure is when it counts. Guys usually learn when they blow the hgs or toss a rod thru the side
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I dont have a gauge on the rail, I checked it with a know good hand held gauge. but yes I know I really need to have on to read constantly. Steve what is your opinion on the difference in MPH from the power logger and the time slip, Do I need to change my speed sensor, on regular drive with a GPS I am only off by 2 MPH (slower than GPS)
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Question -- is a electronic fuel pressure gauge trustworthy, I really don't want to put a gauge on my hood?
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well the pl mph and the time slip mph are apples and oranges. Time slip mph is calculated from the time that it takes to go from one light to another light at the finish line so it is not an instantaneous time. The PL mph is an interpolated, calculated time derived from the ecm's take on the vss input. It has nothing to do with performance in this case.
I never trust the electronic senders when it comes to diagnosing a problem. I just use it as a guide rather than for precise accuracy. I never understood why people want to mount a gauge on the hood like some ricer. It just invites someone to rip it off. Instead, you put the gauge on a hose long enuf to reach the windshield where you tuck it under the wiper arm when you are racing, or want to verify that it is behaving properly. Some use both..they log a sender and tee off the rail to a quality mechanical gauge to be used when needed.
I prefer a large, 1/2 % accuracy gauge about 3" in diameter to use on the windshield and I put a piece of tape on the face marking where I expect the the pressure to rise to and stay thru out the run. That way I don't have to focus on the reading numbers
I suspect your pressure is okay because the chip is dropping the pulse width toward the end of the run. If this is an alky chip, I think it should do that but I would have to double check with Eric. In theory, I would not think it was all that lean ( I have seen 740-750 with no retard), but something is causing it to pull timing.
On the second run, it seemed to be jerking timing on the shifts so it would seem the knock sensor was hearing something bang on the shifts.
My point is that you cannot assume anything. You have to know. Otherwise you are assuming and that always bites you at some time.
It's definitely fat in first and second which reduces off the line power.
The voltage is low as Brad said. You need to see if it is really low or if it is the typical ecm reported voltage low that often happens.
I would probably add 2% to the 3-4 fuel and see what happens
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on the second run I was late on the shift from 2 to 3 and it had started to fall on its face before I shift, that is where I thought the Knock came from.
The 3" fuel gauge is what I use to check for runs around the house taped to the winsheild but was wondering if the electronic would work for a permanent mount in the car.
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I think I answered that above. they are often not precise. Therefore I don't trust them to always give the right answer. If they change the reading, I use a good gauge to find out if the pressure really changed, or if the sender decided to report something else. I have one on one of my cars because I like to log a trend but I only use it for relative changes.
A 7k or more engine is a bit much to risk because I don't want to use a gauge when I think it is required.
Why are you shifting manually? If you need to modify the governor to make it shift where you want to...do so and put it in third gear and concentrate on driving the car. Much more consistency and much less chance of being late or missing the shift
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http://www.motorsportsinnovations.com/wide_band_o2_files/WB_Pressure.htm (http://www.motorsportsinnovations.com/wide_band_o2_files/WB_Pressure.htm)
wb 762 is what I use
When you are at the track, you cannot watch PL and see what is happening...yo u can look at it later which might be too late. The gauge on the windshield tells you real time to quit
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Get a pressure transducer on the fuel rail and run it into the PL.
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ok purchased a new fuel pressure gauge to, taped it to the windshield, pressure was 42 line off 38 line on, i went for a ride I made about four hits, 22psi of boost and 62 psi on the fuel gauge all four times. got back home and put it in park my son noticed that the fuel pressure had dropped to 35 line on, I pulled the line off and it went to 42, I put it back on and it was 34-35. I had Brian go to the back of the car and move the wiring harness for the fuel pump and he said that the pump was kicking on and off (car is running in park). So I goto the back and this is the first time that I ever hear my fuel pump making the winning sound and it was kicking on and off. could it be going bad and just acting up once it has heated up?.
I also reset my TPS -- .42 idle 4.78 full throttle (no floor mat)
I checked voltage -- battery has 14 , alternator 14, scan master 13.7, when my fans kick on the battery and alt. goes to 13.8 and the scan master goes to 13.4.
what are the other important areas to check the see where I am losing between the alt and the ECM
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new walbro 340 is on it way.
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sometimes that is just the way the ecm outputs. Remember that the ecm is converting an analog voltage to a digital output. Sometimes you cannot find out why it is varying.
Check the voltage at the ecm-ign fuse and see what it says. Then drop the column down a bit and wiggle the ignition switch around and see if the voltage changes on the scantool. http://www.vortexbuicks-etc.com/ignition_switch.htm (http://www.vortexbuicks-etc.com/ignition_switch.htm)
I have seen major voltage changes due to bad connections at the switch
And I have seen corroded blades in the fuse block.
And then...I have measured the voltage going into the ecm and it would be several tenths higher than the scantool was showing so go figure. I just figured the ecm was converting to digital and getting the wrong answer
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Thanks guys.
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ok received my new fuel pump and no where on it does it say 340, the numbers stamped on it is f20000169 - 02113-1 , how do I know if its a 255 or 340?
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that is the modern version of the 340. The 340 is a 255 liter/hour pump
that is the number that was failing left and right a few years ago but was supposedly fixed by walbro. I think the 340M was discontinued
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it states that it is good for up to 600hp , I should be ok with this on right
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yep
Grumpy went into the nines on one and spraying alky
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Thanks I just wanted to make sure before I dropped the tank,
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Thanks I just wanted to make sure before I dropped the tank,
When we slapped in a new pump in my dads GN we repainted the straps and tank...looks really clean since you can see the bottom of the tank from the rear...
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installed the new pump today but didnt get to test , what I pulled out of the tank was a GSS307M
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pretty old...but I replaced a 307 a few months ago, myself
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well , I put the fuel pressure gauge on the car and turned the key on and nothing.. both of the relays are working and shutting off after 3 sec, I am by myself and I am guessing it needs to be primed or I did something wrong in the tank, the 307m was already wired in with splices so I just used the connector from that and plugged into the new pump without checking the wires. (I was thinking that they are wired the same). I see on the wiring that there is a wire for pump priming, can someone tell me where it is, or do I have to jump the relay . remember I still have the 85 wiring
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if the pump is sitting in gasoline, it should need no priming.
on the ic cars, the pump test connector comes out of the wiring harness just below the alternator at the front end of the valve cover...also the tach connector. Pump connector is a single gray wire. Put 12 volts to it and the pump should run continually.
Did you hear the pump run for a couple of seconds when the key was turned on?
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no I did not hear the pump, I guess the tank will have to come back down. :013:
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before you do that...run a power feed straight to the back of the car and put power to the pump directly
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I have the racetronix hot wire kit , I had my son under the car last night checking voltage, there was 8v on one wire for 3 seconds when key was turned on, I dont know which wire it was. there is a black , purple, and red . I am assuming that the black is ground and red for sending unit and purple for pump.
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I am guessing your assumptions might be wrong-I don't have a racetronix hot wire...but it matters not....8 volts will not cut it
Once again, I suggest you apply power from the battery straight to the tan wire that goes to the pump in the factory original harness from the pump
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got under the car to run straight power , and I see the problem, I had smashed the hot wire kit power wire in the bolt the holds the tank strap, burnt fuse, gotta love working in the dark. thanks Steve for being patient :rock:
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when you get as old as me, patience is a necessity even if not a virtue...
I almost dropped the tank on one of mine recently until I convinced myself to check everything out first....