unplugged all the sensors
04-07-2005, 02:22 PM
#1
Burning Brakes
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unplugged all the sensors
car is still running rich. read the service manual yesterday all day about the various sensors that control how much fuel the ecm delivers the three main ones are the map, tps, and o2 plus others. the book also says that while unplugged or bad the ecm will rely on default values. so i unplugged each one one at a time then all three plus the egr at the same time did not change one bit my eyes are still burning. also im not getting check engine lights any way for any of the sensors so i really dont think there is a problem with them. so do yall think there could be an ignition problem in the chamber the timing is 24 degrees with a msd 6a ignition box. thanks for any help .
04-07-2005, 02:41 PM
#2
Team Owner
That 24* timing, is that with the little test wire disconnected? If so, that's WAY advanced. Base timing should be about 6* BTDC.
As for running rich, don't be surprised if the injectors are bad, especially if they are OE.
As for running rich, don't be surprised if the injectors are bad, especially if they are OE.
04-07-2005, 03:02 PM
#3
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The timing wouldn't make it run rich. The fact that it didn't run any different with the sensors disconnected, makes it sound like you're not getting out of open loop. Was it warmed up? How is the idle? A possibility is the engine coolant temp sensor in the front of the intake.
What year? Any mods? What led up to this problem, a repair or mod?
What year? Any mods? What led up to this problem, a repair or mod?
04-07-2005, 03:05 PM
#4
Le Mans Master
Originally Posted by steve1ph2
car is still running rich. read the service manual yesterday all day about the various sensors that control how much fuel the ecm delivers the three main ones are the map, tps, and o2 plus others. the book also says that while unplugged or bad the ecm will rely on default values. so i unplugged each one one at a time then all three plus the egr at the same time did not change one bit my eyes are still burning. also im not getting check engine lights any way for any of the sensors so i really dont think there is a problem with them. so do yall think there could be an ignition problem in the chamber the timing is 24 degrees with a msd 6a ignition box. thanks for any help .
Have you tried pulling any stored error code? Is the engine going closed loop?
There are a lot of trouble-shooting tests that can be done to try to find the source of the problem, but using a ScanTool would BY FAR be the easiest way to zero in on the cause.
Otherwise, it'll be very time consuming for everybody concerned.
Jake
04-07-2005, 06:46 PM
#5
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Originally Posted by bogus
As for running rich, don't be surprised if the injectors are bad, especially if they are OE.
04-07-2005, 07:51 PM
#6
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St. Jude Donor '05-'06
If you unplugged the O2 sensors and did not get a fault you are not getting out of open loop. What does you temp gauge say?
Sounds like the one in the front of the block is not sending temp to the ECM telling it to go out of open loop.
Sounds like the one in the front of the block is not sending temp to the ECM telling it to go out of open loop.
Last edited by Redeasysport; 04-07-2005 at 08:07 PM.
04-07-2005, 07:56 PM
#7
Le Mans Master
Originally Posted by Redeasysport
If you unplugged the O2 sensors and did not get a fault you are not getting out of closed loop. What does you temp gauge say?
Sounds like the one in the front of the block is not sending temp to the ECM telling it to go out of closed loop.
Sounds like the one in the front of the block is not sending temp to the ECM telling it to go out of closed loop.
Jake
04-07-2005, 08:04 PM
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St. Jude Donor '05-'06
Sorry Jake you are correct open loop I am deslexic today I guess but the point remains the same you will get a fault if the engine is hot and O2 sensors are disconnected unless the temp sensor is bad/disconnected it will keep the BLM's set to 128
04-07-2005, 10:46 PM
#9
Le Mans Master
Originally Posted by Redeasysport
Sorry Jake you are correct open loop I am deslexic today I guess but the point remains the same you will get a fault if the engine is hot and O2 sensors are disconnected unless the temp sensor is bad/disconnected it will keep the BLM's set to 128
I think I hold the all-time-indoor-record for stuff like that. LOL
Jake
04-08-2005, 01:07 AM
#10
Burning Brakes
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jake, seems we are right down the road from each other. i live in richardson and work over off 35 and regal row. as for your question about the timing thats where we set it. let me give you a quick parts list.`90 6speed, stroked 383, 224/230 bullet racing cam, stock 24lbs injectors, headmen long tube headers, accel super ram intake all three pieces, 58mm tb, breathless ram air kit, 8.5 msd wires with a msd 6a ignition box, gutted cat with borla exhaust. this thing screams. but it also runs rich and it seems like it always has since i redone the motor more or less at times. havent been able to shake it. the guy (jim) who set the timing also builds race motors in rockwall. any how the only sensor i havent messed with is the temp. already called jim and if the temp sensor doesnt do it then im going to drop the car off on sunday at his house. then i will be out of your hair. thanks for your help.
04-08-2005, 01:39 AM
#11
Le Mans Master
Yea, I see we are just about neightbors. I'm about 1 mile west of I-35E off BeltLine Road in DeSoto.
Did you have any PROM work done after making those mods to the engine?
I saw that you listed map. That could be at the core of the problem.
Jake
Did you have any PROM work done after making those mods to the engine?
I saw that you listed map. That could be at the core of the problem.
Jake
04-08-2005, 02:34 AM
#12
Burning Brakes
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somebody had already put an after market eprom. the name of the chip is superchip they are out of california. iv called them befor. my best guess is that the chip was little more than timing and switch to forth gear light eliminator cause the mods done to the motor when i got the car was the exhaust system. there is no dought if the car was running perfect i still need some chip work to relize the full potental of all the mods. there is a place in oklahoma that does that stuff for around $800 the guys name is ed wright. heck i would be scared to see how much faster the car would go. beat an 05 from light to light couple of months ago in oakcliff had a passenger as a witness. your right about the map tried that. going to see whats up on the temp switch today. thanks. i have the gm service manuals if i can help you in anyway.
04-08-2005, 05:38 PM
#15
Le Mans Master
Originally Posted by steve1ph2
somebody had already put an after market eprom. the name of the chip is superchip they are out of california. iv called them befor. my best guess is that the chip was little more than timing and switch to forth gear light eliminator cause the mods done to the motor when i got the car was the exhaust system. there is no dought if the car was running perfect i still need some chip work to relize the full potental of all the mods. there is a place in oklahoma that does that stuff for around $800 the guys name is ed wright. heck i would be scared to see how much faster the car would go. beat an 05 from light to light couple of months ago in oakcliff had a passenger as a witness. your right about the map tried that. going to see whats up on the temp switch today. thanks. i have the gm service manuals if i can help you in anyway.
Have you tried the jumper wire in the ALDL to see if the system is going closed loop after 5 or more minutes.?
If it not going closed loop, the system is running off pre-programmed maps in the PROM and since you are running an aftermarket PROM, they could be programmed too rich for your combination.
Jake
04-08-2005, 06:17 PM
#16
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Originally Posted by JAKE
Ed Wright's in Tulsa,
Have you tried the jumper wire in the ALDL to see if the system is going closed loop after 5 or more minutes.?
If it not going closed loop, the system is running off pre-programmed maps in the PROM and since you are running an aftermarket PROM, they could be programmed too rich for your combination.
Jake
Have you tried the jumper wire in the ALDL to see if the system is going closed loop after 5 or more minutes.?
If it not going closed loop, the system is running off pre-programmed maps in the PROM and since you are running an aftermarket PROM, they could be programmed too rich for your combination.
Jake
How would a jumper show if its going into closed loop ? What would be the signs ? Just curious !
04-08-2005, 06:37 PM
#17
Le Mans Master
Originally Posted by Thatthingsscary!
How would a jumper show if its going into closed loop ? What would be the signs ? Just curious !
I've forgotten (but I can look it up if you need me too) the rate of the flashes the indicates open loop or closed loop, but the SES will blink on and off a different intervals depending on the loop it's in.
Jake
04-08-2005, 06:43 PM
#18
Le Mans Master
I found it:
Two and one half times per second indicates open loop.
1 time per second indicates closed loop.
In closed loop, the SES will also show if the system is running rich or lean (but not how much) by how long the light stays "On" or "Out".
"On" most of the time is rich and "Out" most of the time indicates lean.
Jake
Two and one half times per second indicates open loop.
1 time per second indicates closed loop.
In closed loop, the SES will also show if the system is running rich or lean (but not how much) by how long the light stays "On" or "Out".
"On" most of the time is rich and "Out" most of the time indicates lean.
Jake
04-08-2005, 07:05 PM
#19
Burning Brakes
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jake, the last couple post sound promising, iv been out there half the day today with no luck as soon as i unplugged the temp switch both fans came on left it like that till the car finally got hot enuf to start the puffing and eye burn around 160-180 deg. left it running and tried other things that did not work. tried a diffrent o2 as well. i just got out of the shower i had to wash the gas smell off. so first thing sat morning i will try to determin which loop im in. also found a place today to buy zr1 or zo6 chrome wheels new for right at $700. will post later. thanks.