5500 car falls flat on face
06-03-2012, 08:04 AM
#1
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5500 car falls flat on face I just got it driving and have a small issue i wonder if any of the experts can help with? Have a LQ9 with a cam and 243 heads, headers and a T56. Its got an 850DP right out of the box not touched and runns ok. You have to ease into the carb when getting on it or it bogs. It then runs like crazy until 5500 where it falls flat and misses and pops, you shift to the next gear and it runs great until 5500? Edlebrock 120 gph pump and pill#3 in the MSD. I dont really know **** about car carbs so where do I start? I know it has to be rich a little but I think its more that just a jetting issue?
06-03-2012, 08:26 AM
#2
You're hitting the rev limit on the MSD box. They are set to 5500 RPM out of the box.
To let the good times roll hook up a lap top and it is a simple adjustment to change the rev limit. I have mine at 6600 RPM
To let the good times roll hook up a lap top and it is a simple adjustment to change the rev limit. I have mine at 6600 RPM
06-03-2012, 10:25 AM
#3
the hesitation could be a couple things. Too little initial timing just off idle could be the cause, as could carb calibration.
I would get yourself a wideband O2 sensor to help tune it. It is EXTREMELY helpfull.
Id start by setting initial timing to AT LEAST 20* from below idle speed.
Then move to the carb, check accel pump linkage - needs to have NO clearence between the lever to cam, and set cam to pos 2.
If that doesnt help, I would go up on shooter size to try fix the hesitation. your 850 probably has 31 shooter in the primary, Id step up to a 35, and maybe even a 37. Go up in steps.
I would get yourself a wideband O2 sensor to help tune it. It is EXTREMELY helpfull.
Id start by setting initial timing to AT LEAST 20* from below idle speed.
Then move to the carb, check accel pump linkage - needs to have NO clearence between the lever to cam, and set cam to pos 2.
If that doesnt help, I would go up on shooter size to try fix the hesitation. your 850 probably has 31 shooter in the primary, Id step up to a 35, and maybe even a 37. Go up in steps.
06-03-2012, 11:18 AM
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Thats sweet Pop n Wood I read the Msd directions and it doesnt say anything about the 5500 limit I think it says the pills go to 7000. I will definatly fix that if its that simple.
3 pedals thanks I will change the initial timing a couple of degrees and have it come in a little quicker as well. Thanks for the ideas fellas
3 pedals thanks I will change the initial timing a couple of degrees and have it come in a little quicker as well. Thanks for the ideas fellas
06-03-2012, 05:49 PM
#5
The pills are a LIE!!!! LOL, yea, first test drive when i did my first swap, i was driving, smashed it, and then *bangbangbangbangbang*, at 5500, i was like"WTF? Party was just getting started???" Upped the rev at first to 6500, then to 6800, then to 7000, then greedy at 7200, still spinning that high 3 years later.
06-03-2012, 08:34 PM
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Ok Thats such a relief to here. Now I have to find some kind of tutorial because Im not really a computer genious to be programing this stuff
The pills are a LIE!!!! LOL, yea, first test drive when i did my first swap, i was driving, smashed it, and then *bangbangbangbangbang*, at 5500, i was like"WTF? Party was just getting started???" Upped the rev at first to 6500, then to 6800, then to 7000, then greedy at 7200, still spinning that high 3 years later.
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06-10-2012, 07:13 PM
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OK I finally got a chance to putz with the car today, then I had to deal with a dinasour computer to work on the MSD because the stupid cable that came with me 6010 box doesnt go to a modern laptop, what is MSD thinking?. They send out an out of date printer cable for adjusting the MSD,.,.,. anyway I borrowed my 7yr olds relic computer and got it done. Zone89RS you were right it is simple. I used the #6 pill because it has more initial timing and tops out at 36 degrees. Then I raised the Rev limit to 7000rpm. Holy cow is this little foxbody crazy now. I just put 275 drag radial on it but its lighting them up in 3rd gear( I did have 30lbs in them) and just lowered them to 24lbs, we'll have to see if that helps. The extra timing helped a little of the bogging but I'll have to fine tune it. I also put in a 160 thermostat today to bring down the temps. Now I just have to work on the back end a little to get some traction but damn is this thing a different animal after 5500, Thanks guys I love this forum.
PS sorry to here about your Camaro Zone, glad your not dented up though.
PS sorry to here about your Camaro Zone, glad your not dented up though.
