What would cause the car to do this?
#1
Supreme Member
Thread Starter
iTrader: (8)
Join Date: Jan 2000
Location: Macedonia ,OH
Posts: 3,968
Likes: 0
Received 1 Like
on
1 Post
Car: Formula
Engine: 6.0 LSX
Transmission: 4L60E
Axle/Gears: 9 Bolt 3:27
What would cause the car to do this?
When cold/warm or whatever I'll rev the car up then the rpms will drop to like 350/400 almost die then come back to 700. Any Clues?
#3
Supreme Member
Thread Starter
iTrader: (8)
Join Date: Jan 2000
Location: Macedonia ,OH
Posts: 3,968
Likes: 0
Received 1 Like
on
1 Post
Car: Formula
Engine: 6.0 LSX
Transmission: 4L60E
Axle/Gears: 9 Bolt 3:27
naw I'm running an MSD Coil , 6AL which bypasses the Ignition module, MSD Cap rotor , new pickup coil, new wires, new plugs, timed at 6*
#4
Supreme Member
Would seem your IAC may not be operating correctly...or isn't getting the correct info to operate as you need it.
IAC should maintain the idle RPMs for all occaisions..i/e under a load coming to a stop, or winding down in neutral.
Can you scan the ECM to see what to IAC is doing? i/e the counts?
IAC should maintain the idle RPMs for all occaisions..i/e under a load coming to a stop, or winding down in neutral.
Can you scan the ECM to see what to IAC is doing? i/e the counts?
#5
Supreme Member
Thread Starter
iTrader: (8)
Join Date: Jan 2000
Location: Macedonia ,OH
Posts: 3,968
Likes: 0
Received 1 Like
on
1 Post
Car: Formula
Engine: 6.0 LSX
Transmission: 4L60E
Axle/Gears: 9 Bolt 3:27
I have a tech 1 scanner which shows the counts. Now I have never used this feature yrt. What should it read at idle and when i rev it up and let it come down should it hit teh same count as idle or go like -2 then come to the count for idle?
#6
Supreme Member
Join Date: Apr 2000
Location: Chander, Arizona USA
Posts: 1,338
Likes: 0
Received 0 Likes
on
0 Posts
Car: 2006 Silverado 1500
Engine: 5.3L
Transmission: 4L60E
you may want to check the fuel pressure regulator diaphram. if it's leaking the high vacuum when caused by the rev down can suck fuel passed the regulator if there is a problem with the diaphram. i've ran into this problem before. also a problem with the minimum air setting can cause problems. what is the block learn numbers showing when this happens?
#7
Supreme Member
Thread Starter
iTrader: (8)
Join Date: Jan 2000
Location: Macedonia ,OH
Posts: 3,968
Likes: 0
Received 1 Like
on
1 Post
Car: Formula
Engine: 6.0 LSX
Transmission: 4L60E
Axle/Gears: 9 Bolt 3:27
Heres the scoop. The FP at idle is 43PSI and 47PSI line disconnected. The FP at idle used to be 38 last year but over the winter I put in a new Walbro 255 unit and the pressure seems to be higher. blm's are 126/129 idle reved up and come down are 119/135 this is after a TF head swap and a Xtreme cam. I'm running the stock chip still.
Trending Topics
#8
Supreme Member
Join Date: Oct 2001
Location: orlando, fl usa
Posts: 1,392
Likes: 0
Received 3 Likes
on
3 Posts
Car: 1986 pontiac TA
Engine: 360 HSR
Transmission: 700r4 3300 yank converter
Axle/Gears: 3.27 9 bolt
Originally posted by Mkos1980
Heres the scoop. The FP at idle is 43PSI and 47PSI line disconnected. The FP at idle used to be 38 last year but over the winter I put in a new Walbro 255 unit and the pressure seems to be higher. blm's are 126/129 idle reved up and come down are 119/135 this is after a TF head swap and a Xtreme cam. I'm running the stock chip still.
Heres the scoop. The FP at idle is 43PSI and 47PSI line disconnected. The FP at idle used to be 38 last year but over the winter I put in a new Walbro 255 unit and the pressure seems to be higher. blm's are 126/129 idle reved up and come down are 119/135 this is after a TF head swap and a Xtreme cam. I'm running the stock chip still.
#10
Supreme Member
Join Date: Oct 2001
Location: orlando, fl usa
Posts: 1,392
Likes: 0
Received 3 Likes
on
3 Posts
Car: 1986 pontiac TA
Engine: 360 HSR
Transmission: 700r4 3300 yank converter
Axle/Gears: 3.27 9 bolt
Originally posted by Mkos1980
218/224 .496/.503 .521/.528 1.6RR's and 112 LSA
218/224 .496/.503 .521/.528 1.6RR's and 112 LSA
#11
Supreme Member
Join Date: Apr 2000
Location: Chander, Arizona USA
Posts: 1,338
Likes: 0
Received 0 Likes
on
0 Posts
Car: 2006 Silverado 1500
Engine: 5.3L
Transmission: 4L60E
i'd agree, that's alot of cam with a stock chip to have no idle problems. do you have any numbers with the t.p.s reading at idle and mass air flow numbers at just a normal idle?
#12
Supreme Member
Thread Starter
iTrader: (8)
Join Date: Jan 2000
Location: Macedonia ,OH
Posts: 3,968
Likes: 0
Received 1 Like
on
1 Post
Car: Formula
Engine: 6.0 LSX
Transmission: 4L60E
Axle/Gears: 9 Bolt 3:27
I know I am surprised. In Closed loop its 128/127 BLMs Smooth idle at 750 . TPS is .54 I havent checked the MAF Yet. Its brand new but i'll get the readings tomororw. But man does it Haul.
Thread
Thread Starter
Forum
Replies
Last Post
Linson
Auto Detailing and Appearance
40
08-21-2015 02:12 PM