Just got my double pumper in last night. Went for a drive and in first gear while building boost at about 5-7 psi I get a stutter/stumble and once it hits about 10psi its gone and car pulls as it should. I have the fuel pressure at 43 psi I was unable to hot wire the pump as my kit isn't here yet. Any ideas??? Thanks all.
Stutter
- Thread starter L8TRH8R
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How is the doublepumper wired? Hobbs switch to kick on the 2nd pump? If so at how many psi does it kick in? Maybe it's kicking in at 5psi and that's why you're getting the stutter? Maybe the FP reg is slow to let that extra fuel bypass. If monitor/log O2's (WB is possible) do you see it dump rich and then even back out?
Yes Hobbs is supposed to kick on at 10psi. Tomorrow I'll be able to check all the numbers. Do you think giving it like 45 psi-48psi as accufab suggests for the # my car should run would help? I think I'll give it a try if nobody thinks it'll hurt it....
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Could be a ignition part or a sensor going bad. Something you can try, unplug the cam sensor while its running. Be carefull not to get bit by the alternator fan. 
Leave the cam sensor unplugged and go for a cruise. Don't go crazy getting on it. Just see if it cleared up.
Leave the cam sensor unplugged and go for a cruise. Don't go crazy getting on it. Just see if it cleared up.It may make it worse IMO. Any chance you have an FP gauge in the car or are logging FP? Maybe you could see it spike or something. A log would probably be the only way we will know for sure.
Edit: Worse in response to "Do you think giving it like 45 psi-48psi as accufab suggests for the # my car should run would help?". Not you Rick.
Edit: Worse in response to "Do you think giving it like 45 psi-48psi as accufab suggests for the # my car should run would help?". Not you Rick.
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Does it seem RPM or more boost related?
Yes you can get into bosst. You will know right away if it clears it up. You don't have to go crazy.
Yes you can get into bosst. You will know right away if it clears it up. You don't have to go crazy.
I dont think its the ignition parts. If the problem started AFTER the double pumper its fuel related. I believe your stutter/stumble is too much fuel and then its clears up when enough air(boost) is introduced into the engine. Bring your FP down and see what happens. Turn your FP down in your TT chip in First gear and WOT all gears and see what happens. Bring it down about 5% for starters.
Tool to pull it out of the chip??
Is it an updated chip with adjustment thru the throttle and TPS/scanmaster? If not call Eric and get you an updated adjustable chip. You should not have to mess with the regulator at all once you set it initially.
Is it an updated chip with adjustment thru the throttle and TPS/scanmaster? If not call Eric and get you an updated adjustable chip. You should not have to mess with the regulator at all once you set it initially.
Yes its an adjustable chip. Like I said I'm nee to tuning this and I don't have the tools to get into the computer. Ie scan tool. Yes I know I need one and wl purchase one next. In the meantime what should I do? I'm a rookie (obviously) and don't want to hurt my motor as I have a lot invested... Mptpr has about 900 miles still very fresh.
Took 5% fuel out via scantool went for a drive @ 5psi pop pop turned around to go home looked at temp gauge it was at 195.I was a block from home so I limped home shut off car leaking coolant from the back of motor some place radiator was cold with NO fluid checked oil and all the coolant was in the oil. Time for new headgaskets WTF??????? Ive never made over 15 psi in this thing. 17K into the motor and less then 900 miles on it. Plugs on the drivers side look black passenger side look great do you think it went lean on pass side? Please help as NOBODY in my area has a T/R and I'm basiclly on my own here and running out of patience. Thanks guys.(and gals
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Took 5% fuel out via scantool went for a drive @ 5psi pop pop turned around to go home looked at temp gauge it was at 195.I was a block from home so I limped home shut off car leaking coolant from the back of motor some place radiator was cold with NO fluid checked oil and all the coolant was in the oil. Time for new headgaskets WTF??????? Ive never made over 15 psi in this thing. 17K into the motor and less then 900 miles on it. Plugs on the drivers side look black passenger side look great do you think it went lean on pass side? Please help as NOBODY in my area has a T/R and I'm basiclly on my own here and running out of patience. Thanks guys.(and gals
If the anti-freeze is in the oil don't run the motor at all. You got to flush it out.
Try and pinpoint if its coming from the back of the intake or the head. With the plugs the way you describe them, it sounds like maybe a intake gasket issue. Do you have any way to pressurize the cooling system for testing?
BlackBandit
God loves Buicks!
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Are you running two pumps off of the factory wiring? Just curious.
Get the antifreeze out. Make sure there's no water in the cooling system, fill it with diesel (drain the junk first) and spin the oil pump with a drill. Drain and repeat. When it seems like you've gotten most of it have someone crank the engine while you do it. When you're done flushing put some crap oil in it and do it one more time just so everything is coated with oil.
Get the antifreeze out. Make sure there's no water in the cooling system, fill it with diesel (drain the junk first) and spin the oil pump with a drill. Drain and repeat. When it seems like you've gotten most of it have someone crank the engine while you do it. When you're done flushing put some crap oil in it and do it one more time just so everything is coated with oil.
Its a Red's pump so the first pump is off the factory harness and the second is a 10 gauge wire to the alternater and a hobbs switch is supposed to kick it on at about 10 psi. if you're wondering if it's hotwired the answer is no. I was curious if that was my initial problem though. Not enough "juce" to the pump???I have a kit in the mail.
I'am also hoping it's an intake issue as there was no water on the plugs soooooo I'm hopeful but NOT confident.:frown: I'm not gonna mess with it for a few days. I'm pretty bummed right now.
My wife joked and said one of my best frinds is in a coma... I told her it was no joke!
I appreciate any and all feedback. Thanks a lot. I love these cars so much it was easier in So Cal because I had peple to help, here I'm on my own. The premier race machianist in MT built my motor so I know when we get it it'll be great, but, he lives in another town so kinda a pain in the ass! Took a year to build it too...
