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Fuel Pump

you got it working right, your only gonna see kr when your in the gas hard, run it hard through 2 nd gear.

its the higher rpms you'll likely get/see the kr, like from 3,000 rpm up.
 


ScottyDoggs said:
you got it working right, your only gonna see kr when your in the gas hard, run it hard through 2 nd gear.

its the higher rpms you'll likely get/see the kr, like from 3,000 rpm up.
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I cant really run it out, it wont let me. But when I gave it the gas, right after it hit 3000 it started cutting out, and kr went to around 2.0+/-. Then a little while later pretty much the same scenario except this time I gave it the gas going up an incline, and the kr jumped to 4.0. If I am at a dead stop, put the gas to the floor, it turns the wheels over, pulls you into the seat, it starts to take off like a bat out of hell and when the rpm gets to 3000 it falls flat again. I did not get a chance to pull the plugs last night. Even at highway speeds it does ok, as long as I stay off the pedal and take it easy, of course at highway speeds I would not have much passing power.

What am I watching for in kr?
 
Add 180F thermostat to the mod list.

I don't feel that headers are required for that larger pulley. It's not a 3.4 and that's good. Pull the plugs and look for anything obvious. They may even be fouled and need to be replaced. The 2 degrees of KR does show that you have KR...

What grade of fuel did you say you were using? turbo/supercharged need premium, 93/94 if possible, 91 at the very least. That could do it right there.
 
BillBoost37 said:
Add 180F thermostat to the mod list.

I don't feel that headers are required for that larger pulley. It's not a 3.4 and that's good. Pull the plugs and look for anything obvious. They may even be fouled and need to be replaced. The 2 degrees of KR does show that you have KR...

What grade of fuel did you say you were using? turbo/supercharged need premium, 93/94 if possible, 91 at the very least. That could do it right there.
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*Add 180F thermostat to the mod list.
I will make those considerations once the present issue is resolved.

*Pull the plugs and look for anything obvious. They may even be fouled and need to be replaced.
No problem, on my list to do tonight or over the weekend.

*The 2 degrees of KR does show that you have KR...
How do I go about correcting that? My thoughts are that whatever is going on will correct the kr.

*What grade of fuel did you say you were using? turbo/supercharged need premium, 93/94 if possible, 91 at the very least.
Premium, I am on my second tank since taking possession.

When these mods were made, it was never intended to run 12s, 13s or whatever. All that was intended was for it be reliable and an increase of horsepower to make it a little bit better than similar cars out there.
 


I agree that the plugs need to be ruled out. I will. But if no one has any more suggestions, if the plugs check out, I suppose I am going to throw a fuel pump at it. Any more suggestions? This is an every day driver, not intended to raise hell in. Our 400 small block is reserved for that.
 
id just change the plugs to 104 copper plugs, gaped to 0.50. ive played with the gap 58,55 53, 50 always feels best to me.
 
rkm said:
I agree that the plugs need to be ruled out. I will. But if no one has any more suggestions, if the plugs check out, I suppose I am going to throw a fuel pump at it. Any more suggestions? This is an every day driver, not intended to raise hell in. Our 400 small block is reserved for that.
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If you want to rule out the fuel pump look at your O2 sensor and see if it is going lean. Also look at your MAP for vacuum and pressure. I had a situation when I came in this board where the car layed over and I ended up having a check valve in the line leading to the MAP sensor. I checked everything and chased my tail for over a month thinking it was everything from a bad fuel pump to a bad MAF and MAP sensors. I changed the sensors and bought a fuel pump assembly and ended up being a .25 cent T that I needed. I didn't have the Torque app at the time or anything like that. I used a fuel pressure setup and an oil pressure sending unit screwed in where the gauge went on the fuel pressure tester and connected the gauge inside the cabin and used it for a couple of days to see how my pressure was. All that was for nothing Bill ended up spotting the check valve and when I tried it again it was working again so it wasn't the filter I thought it was. I think what you will find is the plugs are bad, but you will be able to tell a lot by playing with the Torque app.

Jeff
 
I pulled the plugs, they were showing their age for sure, but still in good shape and burning clean, real clean. Installed plugs were NGK R TR55 V-power, replaced with the same.

Still did not fix the issue.

What I learned. This setup was designed by an engineer who works(ed) for GM. The previous owner found and contacted him to custom design these mods with certain requirements in mind. Mainly, to walk that fine line between reliability and performance. And to eliminate the need for headers. Now, if I could find who this was.
 
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J57ltr said:
If you want to rule out the fuel pump look at your O2 sensor and see if it is going lean. Also look at your MAP for vacuum and pressure. I had a situation when I came in this board where the car layed over and I ended up having a check valve in the line leading to the MAP sensor. I checked everything and chased my tail for over a month thinking it was everything from a bad fuel pump to a bad MAF and MAP sensors. I changed the sensors and bought a fuel pump assembly and ended up being a .25 cent T that I needed. I didn't have the Torque app at the time or anything like that. I used a fuel pressure setup and an oil pressure sending unit screwed in where the gauge went on the fuel pressure tester and connected the gauge inside the cabin and used it for a couple of days to see how my pressure was. All that was for nothing Bill ended up spotting the check valve and when I tried it again it was working again so it wasn't the filter I thought it was. I think what you will find is the plugs are bad, but you will be able to tell a lot by playing with the Torque app.

Jeff
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Wouldn't you think it would be throwing codes if running lean? It has no codes. I even went as far as creating a situation to cause a code just to see if it was working. I caused a misfire and the check engine light came on immediately. Scanned it and as expected it gave me the code for misfire on cylinder 5, just as planned. As I have mentioned before, I do not think the fuel pump has totally gone bad, just weakening and just cant keep up with demand.
 
If the fuel pump is weak then it will go lean. I didn't get any codes when I wasn't getting a signal to the MAP under boost if I didn't stay in it. It would go pig rich, set timing to 10* ATDC and I would get a MAP MAF correlation error and it would throw me into reduced engine power mode, and lock me out of the throttle. I have an 05' though. The only time I got a code was if I forced it to the floor and stayed into it. If you still believe that the fuel pump is the issue, then look at timing, O2 sensor, and MAP and watch what they do. You can even log the data and put it into a spreadsheet. Set the sample rate to 100ms (.1 Second)

Jeff
 
J57ltr said:
If the fuel pump is weak then it will go lean. I didn't get any codes when I wasn't getting a signal to the MAP under boost if I didn't stay in it. It would go pig rich, set timing to 10* ATDC and I would get a MAP MAF correlation error and it would throw me into reduced engine power mode, and lock me out of the throttle. I have an 05' though. The only time I got a code was if I forced it to the floor and stayed into it. If you still believe that the fuel pump is the issue, then look at timing, O2 sensor, and MAP and watch what they do. You can even log the data and put it into a spreadsheet. Set the sample rate to 100ms (.1 Second)

Jeff
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Ok, I hear ya. But, by that time wouldn't the pressure regulator be trying to do its job of maintaining the pressure of whatever it was that the pump was sending? (I think I asked that correctly)
 


The only thing a regulator is hold the pressure at the preset level, but it is referenced to manifold pressure, or about 1 psi per pound of boost. It's not going to raise the pressure any higher if the flow isn't there. That was one of the reasons I bought an electronic oil pressure gauge and adapted it to attach to the fuel rail so I could moniter fuel pressure real time. I used an oil pressure setup because it was cheap and I was only going to use it for a few days. My system is return less and the regulator is built into the canister in the fuel tank and unused fuel is just dumped into the tank. There's no reference to boost on my car so it sits at a constant 65 psi. I don't ove it for 3 days and never had an issue. My car also layer over but looking at timing and O2, and MAP I could see something was wrong, but didn't put it together even though I knew that Ford used the same checkvalve in other applications and it had no business I my car. Originally when I tested it I thought it was a filter, but it started working correctly and totally messed me up. Look at the other items and anything else you can think of for fuel and watch what's going on.
 
That wasn't a check valve when Jeff posted a picture, it was a "t". No sirreeeeeeee I said, that's a ford part right there, check valve.
 
Oh.. once your issue (which seems to be a reasonable stumper) is cleared up.. you should go read though Jeff's multipage thread. It was a stumper as well, right up until I saw the picture.
 
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