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I was wondering what the tps reading is over 2000 rpm. I still think you have a lean problem off idle.
Values rise after catalytic convertor
- Thread starter poorboy
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IAC should be a little less than 20 counts at idle, with tps set between 0.42-0.48.
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Try blocking off all the vacuum lines at the vacuum block? What happens to the BLMs?
Drop the tps down to .4-.42 key on engine off (it will rise up about .02 when you start it up so will be .42-.44). Somewhere around 0.47-0.48 V the ecm decides you are no longer trying to idle so make sure it's less than .47, and set the throttle screw to get the iac counts down to about 20 idling in gear.
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Have you done the checks we described? IMHO, Ed and Carl have provided some very good information on issues I overlooked.
Will be able to look at the car Monday.
Friend with an 87 T passed his emissions test on the second try. He has an identical setup except he is running a TE44 instead of a TA49. He had to drop the fuel pressure down to 32 psi.
HC at 40km/h was 105. Limit was 106.
He also had an exhaust leak that was easlily heard. Probably crossover pipe.
I will check for exhaust leaks on mine, but I know I don't have one as large as my friend.
Friend with an 87 T passed his emissions test on the second try. He has an identical setup except he is running a TE44 instead of a TA49. He had to drop the fuel pressure down to 32 psi.
HC at 40km/h was 105. Limit was 106.
He also had an exhaust leak that was easlily heard. Probably crossover pipe.
I will check for exhaust leaks on mine, but I know I don't have one as large as my friend.
Used another bottle of propane looking for a vaccum leak. None found so far.
When the car is fairly cold, but in closed loop, the BLM and INT values are similar to a reference car, but when it reaches full operating temperature, the BLM and INT pretty much go to 160.
If I remember correctly, tps at 2000 rpm is about .62.
When the car is fairly cold, but in closed loop, the BLM and INT values are similar to a reference car, but when it reaches full operating temperature, the BLM and INT pretty much go to 160.
If I remember correctly, tps at 2000 rpm is about .62.
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Have you tried blocking all the vacuum lines off and looking at the BLM values? If you disconnect the charcoal cannister, and plug the hoses, do the values drop? What plugs are you running? Did you set the TPS to 0.42 at idle and can you bring the IAC counts to less than 20?
Blocked off the vacuum lines at the vacuum block. BLM and Int still go to 160 in closed loop. IAC is 20 when car is hot.
Removed driver's side valve cover to see if there was a bad lobe on the cam as well.
Going to get smoke pumped through the system to see if there are any leaks that can't be found from propane.
Removed driver's side valve cover to see if there was a bad lobe on the cam as well.
Going to get smoke pumped through the system to see if there are any leaks that can't be found from propane.
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A suggestion....
You refer to other cars :
Friend with an 87 T passed his emissions test on the second try. He has an identical setup except he is running a TE44 instead of a TA49. He had to drop the fuel pressure down to 32 psi.
HC at 40km/h was 105. Limit was 106.
He also had an exhaust leak that was easlily heard. Probably crossover pipe.
1.I suggest you forget what others cars do or don't do... If your car has the broken exhaust, I think you should get it welded, to remove that from the list of possible problems
.. Just because it's a "hairline" crack when cold, doesn't mean it stays that way when hot. [I've welded many and find that the cracks open up when I heat the tube w/ the TIG torch.]
2. The wierd engine operation w/ the scan tools hooked up can be caused by the tool forcing the ECM to go to diagnostic mode..
When you plug the tool in, does the idle rise up over 1000?? If so, that's a signal the ECM is not in "hiway" mode.
Back under my injector bench...
You refer to other cars :
Friend with an 87 T passed his emissions test on the second try. He has an identical setup except he is running a TE44 instead of a TA49. He had to drop the fuel pressure down to 32 psi.
HC at 40km/h was 105. Limit was 106.
He also had an exhaust leak that was easlily heard. Probably crossover pipe.
1.I suggest you forget what others cars do or don't do... If your car has the broken exhaust, I think you should get it welded, to remove that from the list of possible problems
.. Just because it's a "hairline" crack when cold, doesn't mean it stays that way when hot. [I've welded many and find that the cracks open up when I heat the tube w/ the TIG torch.]2. The wierd engine operation w/ the scan tools hooked up can be caused by the tool forcing the ECM to go to diagnostic mode..
When you plug the tool in, does the idle rise up over 1000?? If so, that's a signal the ECM is not in "hiway" mode.
Back under my injector bench...
SOLUTION FOUND!
I thought I better post the source of my problem to add to the archives since none of you came close.
A friend of mine who has been working on cars for almost 40 years was able to discover the problem with my car. When the scan tool was attached, he noticed that the car went back to open loop after being in closed loop and suggested I check all my grounds. The problem was the grounds on the back of the passenger side head had worked loose.
To summarize:
Car had very high HC and CO values
Car showed no codes, but BLM and INT would go to 160.
All sensors were within specifications.
No vaccum leaks or large exhaust leaks.
Problem was ECM was not properly grounded.
Thanks to all that offered suggestions.
I thought I better post the source of my problem to add to the archives since none of you came close.
A friend of mine who has been working on cars for almost 40 years was able to discover the problem with my car. When the scan tool was attached, he noticed that the car went back to open loop after being in closed loop and suggested I check all my grounds. The problem was the grounds on the back of the passenger side head had worked loose.
To summarize:
Car had very high HC and CO values
Car showed no codes, but BLM and INT would go to 160.
All sensors were within specifications.
No vaccum leaks or large exhaust leaks.
Problem was ECM was not properly grounded.
Thanks to all that offered suggestions.
