FUELPRESSURE & SPARK GAP
06-23-2006, 01:08 AM
#1
I ♥ Acer
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FUELPRESSURE & SPARK GAP
Q #1 I have a 87 5.0 with a bbk fpr & fp gauge. fuel pump? i have no idea more than likley its stock. idle fuel gauge reads 29 psi. vac. unpluged 40 this is ok from what i read but when i rev it up and hold it psi shoots up to 40 and then drops to 29 while im holding the rpms up??? why i dont know... i relize injectors are now pulling fuel at a higher rate and this could be why it drops off from 40 but if this is true it should also drop when i pull the vac. line off the fpr but it stays at 40 when rev and holding it with the vac. line unplugged.
Q#2 ok i have the ngk v grove spak plugs and i have gaped them to 55 wrong? no problem yet runs fine
problem is i have a slight ommp / hesitate once in a great while seems to be when im crusing on the highway with very very light pedal pressure could be happing only when i relase gas pedal. other wise it runs great and kicks azz on imports.
Q#2 ok i have the ngk v grove spak plugs and i have gaped them to 55 wrong? no problem yet runs fine
problem is i have a slight ommp / hesitate once in a great while seems to be when im crusing on the highway with very very light pedal pressure could be happing only when i relase gas pedal. other wise it runs great and kicks azz on imports.
06-23-2006, 01:46 AM
#4
5th Gear Member
Join Date: Mar 2005
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Posts: 3,195
RE: FUELPRESSURE & SPARK GAP
ORIGINAL: bossco302
Q #1 I have a 87 5.0 with a bbk fpr & fp gauge. fuel pump? i have no idea more than likley its stock. idle fuel gauge reads 29 psi. vac. unpluged 40 this is ok from what i read but when i rev it up and hold it psi shoots up to 40 and then drops to 29 while im holding the rpms up??? why i dont know... i relize injectors are now pulling fuel at a higher rate and this could be why it drops off from 40 but if this is true it should also drop when i pull the vac. line off the fpr but it stays at 40 when rev and holding it with the vac. line unplugged.
when you dont have the vacuum line on the regulator, it is the same as flooring it, there will be little or no vacuum, it is normal for the pressure to rise to 40 and when you hold the throttle, vacuum will be created by the flow of the engine dropping the pressure.
all this is normal
Q#2 ok i have the ngk v grove spak plugs and i have gaped them to 55 wrong? no problem yet runs fine
0.055 might be a bit on the big side, unless you have a high performance ignition box, that could be where your miss is coming from.
stock plug gap varies from 0.048-0.052.
I use 0.050 most of the time, but recently closed it up to 0.048 because I was missing at part throttle, it cured it mostly.
problem is i have a slight ommp / hesitate once in a great while seems to be when im crusing on the highway with very very light pedal pressure could be happing only when i relase gas pedal. other wise it runs great and kicks azz on imports.
Q #1 I have a 87 5.0 with a bbk fpr & fp gauge. fuel pump? i have no idea more than likley its stock. idle fuel gauge reads 29 psi. vac. unpluged 40 this is ok from what i read but when i rev it up and hold it psi shoots up to 40 and then drops to 29 while im holding the rpms up??? why i dont know... i relize injectors are now pulling fuel at a higher rate and this could be why it drops off from 40 but if this is true it should also drop when i pull the vac. line off the fpr but it stays at 40 when rev and holding it with the vac. line unplugged.
when you dont have the vacuum line on the regulator, it is the same as flooring it, there will be little or no vacuum, it is normal for the pressure to rise to 40 and when you hold the throttle, vacuum will be created by the flow of the engine dropping the pressure.
all this is normal
Q#2 ok i have the ngk v grove spak plugs and i have gaped them to 55 wrong? no problem yet runs fine
0.055 might be a bit on the big side, unless you have a high performance ignition box, that could be where your miss is coming from.
stock plug gap varies from 0.048-0.052.
I use 0.050 most of the time, but recently closed it up to 0.048 because I was missing at part throttle, it cured it mostly.
problem is i have a slight ommp / hesitate once in a great while seems to be when im crusing on the highway with very very light pedal pressure could be happing only when i relase gas pedal. other wise it runs great and kicks azz on imports.
06-23-2006, 01:53 AM
#5
6th Gear Member
Join Date: Feb 2005
Location:
Posts: 5,205
RE: FUELPRESSURE & SPARK GAP
I have my plugs gapped at .054 bc I have a fully upgraded ignition. Also my fuel pressure is at 42 bc I think I have the injectors almost maxed out (havent go the car back on the dyno yet)
06-23-2006, 02:43 PM
#6
2nd Gear Member
Join Date: Jun 2006
Location:
Posts: 223
RE: FUELPRESSURE & SPARK GAP
[quote]ORIGINAL: silver91gt
ORIGINAL: bossco302
Q #1 I have a 87 5.0 with a bbk fpr & fp gauge. fuel pump? i have no idea more than likley its stock. idle fuel gauge reads 29 psi. vac. unpluged 40 this is ok from what i read but when i rev it up and hold it psi shoots up to 40 and then drops to 29 while im holding the rpms up??? why i dont know... i relize injectors are now pulling fuel at a higher rate and this could be why it drops off from 40 but if this is true it should also drop when i pull the vac. line off the fpr but it stays at 40 when rev and holding it with the vac. line unplugged.
when you dont have the vacuum line on the regulator, it is the same as flooring it, there will be little or no vacuum, it is normal for the pressure to rise to 40 and when you hold the throttle, vacuum will be created by the flow of the engine dropping the pressure.
all this is normal
Q#2 ok i have the ngk v grove spak plugs and i have gaped them to 55 wrong? no problem yet runs fine
0.055 might be a bit on the big side, unless you have a high performance ignition box, that could be where your miss is coming from.
stock plug gap varies from 0.048-0.052.
I use 0.050 most of the time, but recently closed it up to 0.048 because I was missing at part throttle, it cured it mostly.
Q #1 I have a 87 5.0 with a bbk fpr & fp gauge. fuel pump? i have no idea more than likley its stock. idle fuel gauge reads 29 psi. vac. unpluged 40 this is ok from what i read but when i rev it up and hold it psi shoots up to 40 and then drops to 29 while im holding the rpms up??? why i dont know... i relize injectors are now pulling fuel at a higher rate and this could be why it drops off from 40 but if this is true it should also drop when i pull the vac. line off the fpr but it stays at 40 when rev and holding it with the vac. line unplugged.
when you dont have the vacuum line on the regulator, it is the same as flooring it, there will be little or no vacuum, it is normal for the pressure to rise to 40 and when you hold the throttle, vacuum will be created by the flow of the engine dropping the pressure.
all this is normal
Q#2 ok i have the ngk v grove spak plugs and i have gaped them to 55 wrong? no problem yet runs fine
0.055 might be a bit on the big side, unless you have a high performance ignition box, that could be where your miss is coming from.
stock plug gap varies from 0.048-0.052.
I use 0.050 most of the time, but recently closed it up to 0.048 because I was missing at part throttle, it cured it mostly.
06-24-2006, 02:21 AM
#7
I ♥ Acer
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Join Date: Jun 2006
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Posts: 137
RE: FUELPRESSURE & SPARK GAP
i only have a msd coil so far but it was also doing when i had them at 44 i have noticed that my temp gauge reads 1 to 2 lines but mostly 1 line above 130 could this be where my problem is? i have a mr gasket 180 stat and a flex fan each line on my stock gauge is at least 23 deg. so im running 153 to 160 i know its just a dummy gauge but is this to cold ? should i go back to stock since im running a flex fan?
06-24-2006, 04:16 AM
#8
5th Gear Member
Join Date: Mar 2006
Location: Massachusetts, New Bedford
Posts: 3,035
RE: FUELPRESSURE & SPARK GAP
what is the correst gappage for the spark plugs for a 5.0 motor w/ what i have on it (see below)? they came 35 in the box should i open them up a bit? and my temp gage when up a little too from 1 line above 130 to 2-2.5 lines
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