Puzzler
Thread Starter
Cruising
Joined: Aug 2016
Posts: 14
Likes: 0
From: belleville pa
Puzzler
Baffled, best describes it. (86 TPI - 40,000miles) ran like a champ last summer, over the winter I pained it, NOW it refuses to run correctly. Symptoms; Idle hunting, popping thru intake, stalls out. It starts right up, runs for a few seconds, then it dies.
Checked for vacuum leaks; visual, spray, and smoke- no vacuum leaks, "I did check the brake booster also"
New items: IAC, TPS, Temp sensor, intake temp sensor, egr,
No codes
IN OPEN LOOP, it will not idle, UNLESS I unplug the coolant temp sensor.
It is suffering form a very lean condition.
Fuel pressure is great 40/47 and it does climb slightly when I open the throttle.
Its as if the computer wasn't giving it enough fuel.
ANY THOUGHTS?????????????????MIKE
Checked for vacuum leaks; visual, spray, and smoke- no vacuum leaks, "I did check the brake booster also"
New items: IAC, TPS, Temp sensor, intake temp sensor, egr,
No codes
IN OPEN LOOP, it will not idle, UNLESS I unplug the coolant temp sensor.
It is suffering form a very lean condition.
Fuel pressure is great 40/47 and it does climb slightly when I open the throttle.
Its as if the computer wasn't giving it enough fuel.
ANY THOUGHTS?????????????????MIKE
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
Maybe the CTS is reading wrong or maybe the CTS unplugging compensates for another problem. Scan it and hit it with an IR Thermometer and see if they are reporting right. See what the other sensors are saying too.
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
Try this. If you pull the MAF plug off and if it settles down, you have an issue.
Thread Starter
Cruising
Joined: Aug 2016
Posts: 14
Likes: 0
From: belleville pa
I did try that, no difference .
Because its so far out of balance, I can only get it to idle if I;
1.pull the IAC connector (after I have jumpered the data link) you know, the IAC set procedure
removed the data jumper
2. unplug the MAF
3. unplug the CTS
4. unplug the EGR solenoid
If I do all that, it will idle with some stability, but if I throttle it, it hesitates, and pops thru the intake. Like its crazy lean.
If I clear all codes and plug everything back together, it idle hunts like crazy.
timing is 6degrees
mike
Because its so far out of balance, I can only get it to idle if I;
1.pull the IAC connector (after I have jumpered the data link) you know, the IAC set procedure
removed the data jumper
2. unplug the MAF
3. unplug the CTS
4. unplug the EGR solenoid
If I do all that, it will idle with some stability, but if I throttle it, it hesitates, and pops thru the intake. Like its crazy lean.
If I clear all codes and plug everything back together, it idle hunts like crazy.
timing is 6degrees
mike
Thread Starter
Cruising
Joined: Aug 2016
Posts: 14
Likes: 0
From: belleville pa
One thing that puzzle me in particular is,
no matter where the throttle blades are set, I can not get the TPS to read the .54volts. I can get it to .45 but then Im out of available TPS adjustment. no where to go.
thanks for the thoughts,
no matter where the throttle blades are set, I can not get the TPS to read the .54volts. I can get it to .45 but then Im out of available TPS adjustment. no where to go.
thanks for the thoughts,
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
Because its so far out of balance, I can only get it to idle if I;
1.pull the IAC connector (after I have jumpered the data link) you know, the IAC set procedure
removed the data jumper
2. unplug the MAF
3. unplug the CTS
4. unplug the EGR solenoid
If I do all that, it will idle with some stability, but if I throttle it, it hesitates, and pops thru the intake. Like its crazy lean.
If I clear all codes and plug everything back together, it idle hunts like crazy.
timing is 6degrees
1.pull the IAC connector (after I have jumpered the data link) you know, the IAC set procedure
removed the data jumper
2. unplug the MAF
3. unplug the CTS
4. unplug the EGR solenoid
If I do all that, it will idle with some stability, but if I throttle it, it hesitates, and pops thru the intake. Like its crazy lean.
If I clear all codes and plug everything back together, it idle hunts like crazy.
timing is 6degrees
I know the procedure. It is for a stock system where there are no mods and everything is working as it should. IOW, it ASSUMES that the ONLY thing out is the TB blades position. There must be NO air leaks, Tach reading right, everything functioning as it should and NO mods. The more mods, the less it is worth. I set mine using a scanner and the IAC counts.
How do you know it is crazy lean? Is your O2 sensor fresh and what is the reading?
I really think that before people mod, they need to consult the guy tuning the chip and do their legwork. Many will ask "What is the best cam for...." and "What is the best intake for....", "What is the best heads for....", etc and then slap all together and make it work. That is probably how clown suits get done. Talk to the guy doing the dyno tuning and ask him what his experience is with his SYSTEM. Sure, you can ask him questions about "Will this cam work with....". but try to make it a SYSTEM otherwise it might have undesirable results. What I would suggest is finding a tuner to help you out with the ECM. That will lead to the least frustration.
BTW, how were the injectors? Did you get stock size or went back with stock Multecs?
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Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
What are you saying? That if you depress the pedal, you cannot get any more than 0.45V? IF so, there is something else wrong. You sure you got the sensor arm set up right?
Thread Starter
Cruising
Joined: Aug 2016
Posts: 14
Likes: 0
From: belleville pa
No modifications to car,
out of balance means, the throttle blade set screw is turned all the way in. FULL OPEN just to get it to idle around 500rpm
TPS it ohms up and down smoothly with no jumping around BUT with the blades fully opened, I can only adjust it to .45V (key on, engine off, in a static position I can only realize .45V)
out of balance means, the throttle blade set screw is turned all the way in. FULL OPEN just to get it to idle around 500rpm
TPS it ohms up and down smoothly with no jumping around BUT with the blades fully opened, I can only adjust it to .45V (key on, engine off, in a static position I can only realize .45V)
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Thread Starter
Cruising
Joined: Aug 2016
Posts: 14
Likes: 0
From: belleville pa
I have not unplugged the Vacuum Line, but if I unplug EGR connector at the control solenoid, the car will idle. If I plug it back in, the car stalls. That's whats very strange to me,. I thought that the EGR stayed closed until the car went into closed loop?????
all of my messing with this car have been done (I think) in open loop, because the engine never gets hot or even warm really. Im still tring to get this thing to just hold an idle.
WHY is the EGR opening in open loop?
Why will this car not idle with the temp sensor plugged in?
Like I said earlier in this thread, before I painted it, (last winter) it ran awesome. But after the paint job, it wont even idle. I changed nothing, mike
all of my messing with this car have been done (I think) in open loop, because the engine never gets hot or even warm really. Im still tring to get this thing to just hold an idle.
WHY is the EGR opening in open loop?
Why will this car not idle with the temp sensor plugged in?
Like I said earlier in this thread, before I painted it, (last winter) it ran awesome. But after the paint job, it wont even idle. I changed nothing, mike
Drifting
Joined: Jun 2018
Posts: 1,678
Likes: 229
From: Michigan
You do not need a scanner... you can use a Laptop, WinALDL (Tuner Pro or other) and a cable. The software is free. Trust me... You can see the MAF signal, BLMs, integrator, O2 Voltage, TPS voltage and CTS's all in real time by what your computer sees. Even if you can get readings at the sensors, does not mean it is returning the signal to the computer correctly. Tryign to do this without seeing this information results in just tossing parts at it.
The TPS has some adjustment in it's mounting screws. If you can't rotate it counter clockwise and set the idle screw out and not reach a .5V, either the TPS is bad or the voltage getting to the TPS is out of spec (5V).
Have checked the injectors? While your fuel pressure may be good, doesn't mean the spray is getting into the intake runner. Was the gas treated? Are you sure the injectors have not varnished up? Here we are in October and you are stating you had it set over the winter for a paint job. What has happened over spring/summer this year? You may want to disconnect your fuel line and pump the system dry and start with fresh gas with a cleaner in it... but man that TPS just sounds wacky.
The OEM injectors have proven to be about a 30 year injector in the F-Body world.
The TPS has some adjustment in it's mounting screws. If you can't rotate it counter clockwise and set the idle screw out and not reach a .5V, either the TPS is bad or the voltage getting to the TPS is out of spec (5V).
Have checked the injectors? While your fuel pressure may be good, doesn't mean the spray is getting into the intake runner. Was the gas treated? Are you sure the injectors have not varnished up? Here we are in October and you are stating you had it set over the winter for a paint job. What has happened over spring/summer this year? You may want to disconnect your fuel line and pump the system dry and start with fresh gas with a cleaner in it... but man that TPS just sounds wacky.
The OEM injectors have proven to be about a 30 year injector in the F-Body world.
Last edited by KyleF; Oct 17, 2018 at 11:52 AM.
Racer
Joined: May 2008
Posts: 312
Likes: 19
Many times the battery gets killed during a paint or body job. Sounds lean, injectors, vac leak could be under manifold, cts. I would ohm out the cts, if thats ok then check ex manifold for cold/dead cylinders, batt 12.7 v fully charged? then back to vac leaks. Good luck!
Oil Producer
Joined: Apr 2014
Posts: 9,377
Likes: 2,737
unplug the egr control module and do the minimum idle set procedure.
ak is right that the min idle set isnt perfect but it should give u an improvement and get close unless u have something real weird out.
its possible you have a rupture in your egr valve.
ak is right that the min idle set isnt perfect but it should give u an improvement and get close unless u have something real weird out.
its possible you have a rupture in your egr valve.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Check the EGR by disconnecting the vacuum source and plugging. If it "fixes" the car, then you need to test for a short to ground on the EGR circuit.
.
Last edited by Tom400CFI; Oct 17, 2018 at 03:07 PM.
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
You do not need a scanner... you can use a Laptop, WinALDL (Tuner Pro or other) and a cable. The software is free. Trust me... You can see the MAF signal, BLMs, integrator, O2 Voltage, TPS voltage and CTS's all in real time by what your computer sees. Even if you can get readings at the sensors, does not mean it is returning the signal to the computer correctly. Tryign to do this without seeing this information results in just tossing parts at it.
The OEM injectors have proven to be about a 30 year injector in the F-Body world.
The OEM injectors have proven to be about a 30 year injector in the F-Body world.
Multec vs ethanol is an interesting match.
Oil Producer
Joined: Apr 2014
Posts: 9,377
Likes: 2,737
EGR should stay closed until cruising operation. However, if the EGR solenoid circuit were shorted to ground, the EGR would be open all the time....and you'd have a major vacuum leak (of mixed air and exhaust).
Check the EGR by disconnecting the vacuum source and plugging. If it "fixes" the car, then you need to test for a short to ground on the EGR circuit.
.
Check the EGR by disconnecting the vacuum source and plugging. If it "fixes" the car, then you need to test for a short to ground on the EGR circuit.
.
Melting Slicks
Joined: Jan 2014
Posts: 2,192
Likes: 381
From: Lunenburg MA
You do not need a scanner... you can use a Laptop, WinALDL (Tuner Pro or other) and a cable. The software is free. Trust me... You can see the MAF signal, BLMs, integrator, O2 Voltage, TPS voltage and CTS's all in real time by what your computer sees. Even if you can get readings at the sensors, does not mean it is returning the signal to the computer correctly. Tryign to do this without seeing this information results in just tossing parts at it.
The TPS has some adjustment in it's mounting screws. If you can't rotate it counter clockwise and set the idle screw out and not reach a .5V, either the TPS is bad or the voltage getting to the TPS is out of spec (5V).
Have checked the injectors? While your fuel pressure may be good, doesn't mean the spray is getting into the intake runner. Was the gas treated? Are you sure the injectors have not varnished up? Here we are in October and you are stating you had it set over the winter for a paint job. What has happened over spring/summer this year? You may want to disconnect your fuel line and pump the system dry and start with fresh gas with a cleaner in it... but man that TPS just sounds wacky.
The OEM injectors have proven to be about a 30 year injector in the F-Body world.
The TPS has some adjustment in it's mounting screws. If you can't rotate it counter clockwise and set the idle screw out and not reach a .5V, either the TPS is bad or the voltage getting to the TPS is out of spec (5V).
Have checked the injectors? While your fuel pressure may be good, doesn't mean the spray is getting into the intake runner. Was the gas treated? Are you sure the injectors have not varnished up? Here we are in October and you are stating you had it set over the winter for a paint job. What has happened over spring/summer this year? You may want to disconnect your fuel line and pump the system dry and start with fresh gas with a cleaner in it... but man that TPS just sounds wacky.
The OEM injectors have proven to be about a 30 year injector in the F-Body world.
