Flat spot WOT
12-14-2013, 03:34 PM
#1
Registered User
Thread Starter
Join Date: Sep 2013
Posts: 11
Flat spot WOT
I have a flat spot on WOT. car seems to pull decent, but not like it used too.
About the car:
The car is a 81 non turbo with a 83 turbo engine.
garret .60 trim turbo @12 PSI
haltech E6k Programmable ECU with 3 bar MAP.
MSD 6A ignition box.
HKS Blow off valve.
Tial 38mm wastegate.
DSM 440cc injectors
walbro 255LPH fuel pump
Blaster 2 ignition coil
intercooler 2"D x 15" T x 20" L
5 speed transmission.
i do have a fuel pressure gauge on it. had problems with crap in the tank, so i put a filter before and after the fuel pump. (need to get around to cleaning out the tank)
The problem:
the problem im having is the car seems to run fine at idle, lower speeds. and if im cruising down the highway, it runs great. no problems at all. but once i get in it and mash it WOT it just doesnt really wanna go, before when i got on it i could spin 1st, some of 2nd and sometimes even spin a lil in 3rd gear. not dropping the clutch, just holding the gas to the floor.
now if i mash it in 1st gear from a slow roll it doesnt even really spin the tires.
so i guess it did loose torque all around, but mainly noticeable at higher speeds.
overview:
I had a noise in the valve cover. so i pulled the valve cover to investigate, turns out the timing chain was rubbing the tensioner in such a way that it would make noise. after pulling the coil wire and turning the engine over, i noticed that the cam shaft pulley was bent.
when i put the engine back together, i could not find the "proper way" to torque the cam nut, so i put a socket extention through one of the cam sprocket holes and torqued it. wall i guess the 100ft pounds it took to torque the sprocket bolt ended up tweaking the sprocket a fair bit.
so i changed the sprocket..
sounds that easy doesnt it?
no, actually the wedge i put in to hold the chain didnt hold for what ever reason, and the timing chain slipped.. you guessed it, out popped the tensioner. after about 3 hours of trying to get it to go back in (i actually got it to go back in on my other 280zx after about a hour of messing with it)
i gave up and faced the fact that i was going to have to pull the whole cover off.
pulled it all apart and re-timed the chain. put the engine on TDC. lined the shiny links up with the dots on the right side of the crank/cam. on the cam, i set the dowel to 1. out of the notches 1 2 and 3.
(seems like the cam being off a tooth would be more noticable in all RPMs, correct me if im wrong?)
i have searched over and over and not able to find anything on these notches and what they are for. i have been told they are for accounting for timing chain wear as for when the chain stretches, you adjust them accordingly.
i have also been told the 2 should be normal, and the 1 and 3 are advance and retard.
can somebody please clarify this for me?
when i pulled it apart, i did not check which dowel it was in, 1 2 or 3. and did not see any indication of the dowel where it was riding on the cam or the cam sprocket.
i also did not check the ignition timing prior to pulling it apart. read in the Xenon manual it should be 24* +/-3*
Timing is now set to 22* BTDC.
Engine is running a 81 turbo distributor. not a CAS.
{Inside the haltech program, under "ignition set up" it says the "Trigger in angle" the previous owner had it set to 48.
i know this isn't the problem because the car ran great before i pulled the front apart, and none of this has been messed with. i'd just like to know how they came up with the 48, so i could understand timing this thing/working the E6k.}
I read up on timing, it says to *lock the timing* in the haltech.
i do that. it has an option what to change the degree of the timing lock too.
from what i understand you set this at what your setting the base timing too?
in the haltech manual, it says you should be able to rev the engine and the line should not move with the timing locked. mine does not move, until you get up about 3000-4000 rpm and then it goes all over the place???
not sure if this is my problem or not? i figured the timing going to the #1 plug, regardless of what the computer is set too, should show on the timing light?
i know i have alot of questions, and alot to learn with this E6k set up.
i appreciate your help in advance!
the three things that was changed was the distributor was taken off.
intercooler and piping. (did a boost leak test, i had a boost leak, fixed it and still have the problem) and the cam timing, unless im missing something.
thanks! -joel
About the car:
The car is a 81 non turbo with a 83 turbo engine.
garret .60 trim turbo @12 PSI
haltech E6k Programmable ECU with 3 bar MAP.
MSD 6A ignition box.
HKS Blow off valve.
Tial 38mm wastegate.
DSM 440cc injectors
walbro 255LPH fuel pump
Blaster 2 ignition coil
intercooler 2"D x 15" T x 20" L
5 speed transmission.
i do have a fuel pressure gauge on it. had problems with crap in the tank, so i put a filter before and after the fuel pump. (need to get around to cleaning out the tank)
The problem:
the problem im having is the car seems to run fine at idle, lower speeds. and if im cruising down the highway, it runs great. no problems at all. but once i get in it and mash it WOT it just doesnt really wanna go, before when i got on it i could spin 1st, some of 2nd and sometimes even spin a lil in 3rd gear. not dropping the clutch, just holding the gas to the floor.
now if i mash it in 1st gear from a slow roll it doesnt even really spin the tires.
so i guess it did loose torque all around, but mainly noticeable at higher speeds.
overview:
I had a noise in the valve cover. so i pulled the valve cover to investigate, turns out the timing chain was rubbing the tensioner in such a way that it would make noise. after pulling the coil wire and turning the engine over, i noticed that the cam shaft pulley was bent.
when i put the engine back together, i could not find the "proper way" to torque the cam nut, so i put a socket extention through one of the cam sprocket holes and torqued it. wall i guess the 100ft pounds it took to torque the sprocket bolt ended up tweaking the sprocket a fair bit.
so i changed the sprocket..
sounds that easy doesnt it?
no, actually the wedge i put in to hold the chain didnt hold for what ever reason, and the timing chain slipped.. you guessed it, out popped the tensioner. after about 3 hours of trying to get it to go back in (i actually got it to go back in on my other 280zx after about a hour of messing with it)
i gave up and faced the fact that i was going to have to pull the whole cover off.
pulled it all apart and re-timed the chain. put the engine on TDC. lined the shiny links up with the dots on the right side of the crank/cam. on the cam, i set the dowel to 1. out of the notches 1 2 and 3.
(seems like the cam being off a tooth would be more noticable in all RPMs, correct me if im wrong?)
i have searched over and over and not able to find anything on these notches and what they are for. i have been told they are for accounting for timing chain wear as for when the chain stretches, you adjust them accordingly.
i have also been told the 2 should be normal, and the 1 and 3 are advance and retard.
can somebody please clarify this for me?
when i pulled it apart, i did not check which dowel it was in, 1 2 or 3. and did not see any indication of the dowel where it was riding on the cam or the cam sprocket.
i also did not check the ignition timing prior to pulling it apart. read in the Xenon manual it should be 24* +/-3*
Timing is now set to 22* BTDC.
Engine is running a 81 turbo distributor. not a CAS.
{Inside the haltech program, under "ignition set up" it says the "Trigger in angle" the previous owner had it set to 48.
i know this isn't the problem because the car ran great before i pulled the front apart, and none of this has been messed with. i'd just like to know how they came up with the 48, so i could understand timing this thing/working the E6k.}
I read up on timing, it says to *lock the timing* in the haltech.
i do that. it has an option what to change the degree of the timing lock too.
from what i understand you set this at what your setting the base timing too?
in the haltech manual, it says you should be able to rev the engine and the line should not move with the timing locked. mine does not move, until you get up about 3000-4000 rpm and then it goes all over the place???
not sure if this is my problem or not? i figured the timing going to the #1 plug, regardless of what the computer is set too, should show on the timing light?
i know i have alot of questions, and alot to learn with this E6k set up.
i appreciate your help in advance!
the three things that was changed was the distributor was taken off.
intercooler and piping. (did a boost leak test, i had a boost leak, fixed it and still have the problem) and the cam timing, unless im missing something.
thanks! -joel
Last edited by jbtatro; 12-14-2013 at 07:56 PM.
12-17-2013, 01:25 PM
#2
Who created the base tune?
Are you using a wideband O2?
As for the cam sprocket settings, the FSM outlines the #1, 2, 3 positions.
The 81T has the CAS at the actual crank pulley... so are you using that CAS for the signal?
Are you using a wideband O2?
As for the cam sprocket settings, the FSM outlines the #1, 2, 3 positions.
The 81T has the CAS at the actual crank pulley... so are you using that CAS for the signal?
12-21-2013, 11:44 AM
#3
Registered User
Thread Starter
Join Date: Sep 2013
Posts: 11
No, the only pickup coil is inside the distributor.
i believe its a 81, this is the exact distributor here.
The problem ended up being fuel pressure, i noticed my fuel pressure gauge dropping to about 28-30 psi at WOT and before it dropped it ran fine.
cleaned the 30+ year old tank out. got about a good cup of dirt/grime out of it.
cleaned out my fuel pump, fuel lines. couldnt blow through the fuel filter.
changed it. pump runs alot quieter now. and has its original power back.
funny because i put a brand new fuel filter on it about a week prior. pulled it off a week later and you cant blow through it.
As far as the wideband goes, car used to have one but the previous owner took it off. he tuned it a lil on the rich side to be safe.
AEM wide band is in the mail, should be here soon!
trying to find a tachometer that will hook into the MSD 6A box.
from what i can see the only ones that really dont require a adapter is the AUTOMETER and a few others.
anybody have luck with getting any other tachs to work without a adapter?
i believe its a 81, this is the exact distributor here.
The problem ended up being fuel pressure, i noticed my fuel pressure gauge dropping to about 28-30 psi at WOT and before it dropped it ran fine.
cleaned the 30+ year old tank out. got about a good cup of dirt/grime out of it.
cleaned out my fuel pump, fuel lines. couldnt blow through the fuel filter.
changed it. pump runs alot quieter now. and has its original power back.
funny because i put a brand new fuel filter on it about a week prior. pulled it off a week later and you cant blow through it.
As far as the wideband goes, car used to have one but the previous owner took it off. he tuned it a lil on the rich side to be safe.
AEM wide band is in the mail, should be here soon!
trying to find a tachometer that will hook into the MSD 6A box.
from what i can see the only ones that really dont require a adapter is the AUTOMETER and a few others.
anybody have luck with getting any other tachs to work without a adapter?
Last edited by jbtatro; 12-21-2013 at 11:46 AM.
12-26-2013, 11:34 AM
#4
Mr Z++ Wiki
Join Date: Sep 2009
Location: Victoria, BC
Posts: 2,195
No, the only pickup coil is inside the distributor.
i believe its a 81, this is the exact distributor here.
The problem ended up being fuel pressure, i noticed my fuel pressure gauge dropping to about 28-30 psi at WOT and before it dropped it ran fine.
cleaned the 30+ year old tank out. got about a good cup of dirt/grime out of it.
cleaned out my fuel pump, fuel lines. couldnt blow through the fuel filter.
changed it. pump runs alot quieter now. and has its original power back.
funny because i put a brand new fuel filter on it about a week prior. pulled it off a week later and you cant blow through it.
As far as the wideband goes, car used to have one but the previous owner took it off. he tuned it a lil on the rich side to be safe.
AEM wide band is in the mail, should be here soon!
trying to find a tachometer that will hook into the MSD 6A box.
from what i can see the only ones that really dont require a adapter is the AUTOMETER and a few others.
anybody have luck with getting any other tachs to work without a adapter?
i believe its a 81, this is the exact distributor here.
The problem ended up being fuel pressure, i noticed my fuel pressure gauge dropping to about 28-30 psi at WOT and before it dropped it ran fine.
cleaned the 30+ year old tank out. got about a good cup of dirt/grime out of it.
cleaned out my fuel pump, fuel lines. couldnt blow through the fuel filter.
changed it. pump runs alot quieter now. and has its original power back.
funny because i put a brand new fuel filter on it about a week prior. pulled it off a week later and you cant blow through it.
As far as the wideband goes, car used to have one but the previous owner took it off. he tuned it a lil on the rich side to be safe.
AEM wide band is in the mail, should be here soon!
trying to find a tachometer that will hook into the MSD 6A box.
from what i can see the only ones that really dont require a adapter is the AUTOMETER and a few others.
anybody have luck with getting any other tachs to work without a adapter?
If your tank was full of gunk it's no mystery that the new fuel filter would be clogged in a week.
Do you need an MSD box if you are running and aftermarket ECU?
Need a WB02 to tune properly....
02-01-2014, 01:15 PM
#6
Registered User
Thread Starter
Join Date: Sep 2013
Posts: 11
Took off the fuel filter and it runs like a bat out of hell.. until the fuel pump gets plugged. (i have a fuel filter at the original location between the fuel pump and fuel rail.
it seems these walbro fuel pumps are EXTREMELY sensitive to dirt or grime. i think the stock fuel pumps are alot more forgiving. i put a new fuel filter between the fuel pump and tank. this seems to have fixed my problem it just doesnt seem like i have the same amount of power (maybe its just me) with a fuel filter on vs without one.
i was looking in to a high flow fuel filter? any recommendations? i was just concerned that two (stock) fuel filters might be reducing the flow of fuel down quite a bit.
it seems these walbro fuel pumps are EXTREMELY sensitive to dirt or grime. i think the stock fuel pumps are alot more forgiving. i put a new fuel filter between the fuel pump and tank. this seems to have fixed my problem it just doesnt seem like i have the same amount of power (maybe its just me) with a fuel filter on vs without one.
i was looking in to a high flow fuel filter? any recommendations? i was just concerned that two (stock) fuel filters might be reducing the flow of fuel down quite a bit.
02-02-2014, 07:27 PM
#7
Mr Z++ Wiki
Join Date: Sep 2009
Location: Victoria, BC
Posts: 2,195
Fix the source of your problem or you'll just keep banging your head. Get the tank out and cleaned. Clean the sender while you have the tank out. Blow the fuel lines out and run new fuel hose between the hard line and your connections. Replace all the filters. Start with a good system instead of clogging it up constantly with a dirty tank.
Doesn't need to be as fine as the one in the engine bay for the injectors...
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