Stumbles from idle
Site Moderator
Joined: Jan 2008
Posts: 8,374
Likes: 28
From: Sioux Falls, SD
MAF sensors actually detects the mass flowrate of air into the intake manifold.
MAP sensors detect the air pressure inside the intake manifold.
They both help the engine's computer determine A/F ratio, but are two very different types of systems, and are almost never used together on the same engine.
MAP sensors detect the air pressure inside the intake manifold.
They both help the engine's computer determine A/F ratio, but are two very different types of systems, and are almost never used together on the same engine.
Last edited by jasonw; Oct 20, 2013 at 07:52 PM. Reason: Grammar correction.
Thread Starter
|
Registered User
Joined: Oct 2013
Posts: 4
Likes: 0
Update:
I checked all the vacuum lines and couldn't find any breaks. I tried spraying them all with a little carb cleaner and the rpms never jumped.
Then I checked the TPS and MAP sensors. The connections seemed clean so I plugged them in and out a few times to clean the connections as suggested.
After that I disconnected the battery to clear the computer and took it for a test drive.
Results:
The truck ran a lot better. It didn't stumble from idle and I think my powerband was back to normal.
I only drove it a few miles so I don't think I'm out of the woods yet but I'll keep you posted. I'm concerned because I don't have anything specific to blame it on but I'm glad it's running better.
...I miss the days of simple engines with mechanical parts that were easy to diagnose and fix.
I checked all the vacuum lines and couldn't find any breaks. I tried spraying them all with a little carb cleaner and the rpms never jumped.
Then I checked the TPS and MAP sensors. The connections seemed clean so I plugged them in and out a few times to clean the connections as suggested.
After that I disconnected the battery to clear the computer and took it for a test drive.
Results:
The truck ran a lot better. It didn't stumble from idle and I think my powerband was back to normal.
I only drove it a few miles so I don't think I'm out of the woods yet but I'll keep you posted. I'm concerned because I don't have anything specific to blame it on but I'm glad it's running better.
...I miss the days of simple engines with mechanical parts that were easy to diagnose and fix.
Veteran
Joined: Aug 2011
Posts: 260
Likes: 0
From: Buckley ,Washington
Yeah 70's engines are so much easier to diagnos! barely any electronics. If it didn't work properly, you just do a tune up and it fixes it for the most part. Keep us in touch! Feel free to PM if you'd like more help.
Amateur
Joined: Oct 2013
Posts: 25
Likes: 0
Update:
I checked all the vacuum lines and couldn't find any breaks. I tried spraying them all with a little carb cleaner and the rpms never jumped.
Then I checked the TPS and MAP sensors. The connections seemed clean so I plugged them in and out a few times to clean the connections as suggested.
After that I disconnected the battery to clear the computer and took it for a test drive.
Results:
The truck ran a lot better. It didn't stumble from idle and I think my powerband was back to normal.
I only drove it a few miles so I don't think I'm out of the woods yet but I'll keep you posted. I'm concerned because I don't have anything specific to blame it on but I'm glad it's running better.
...I miss the days of simple engines with mechanical parts that were easy to diagnose and fix.
I checked all the vacuum lines and couldn't find any breaks. I tried spraying them all with a little carb cleaner and the rpms never jumped.
Then I checked the TPS and MAP sensors. The connections seemed clean so I plugged them in and out a few times to clean the connections as suggested.
After that I disconnected the battery to clear the computer and took it for a test drive.
Results:
The truck ran a lot better. It didn't stumble from idle and I think my powerband was back to normal.
I only drove it a few miles so I don't think I'm out of the woods yet but I'll keep you posted. I'm concerned because I don't have anything specific to blame it on but I'm glad it's running better.
...I miss the days of simple engines with mechanical parts that were easy to diagnose and fix.
Veteran
Joined: Aug 2011
Posts: 260
Likes: 0
From: Buckley ,Washington
Mine stumbles when it starts. Maybe its cuz I don't drive it anymore. I got a car a 1.5 years ago and been driving That ever since for mileage and only used truck in winter. Maybe its cuz mine has bad gas, not sure.
Rsjuza, let us know if its still running better. Hope it is!
Rsjuza, let us know if its still running better. Hope it is!
Thread Starter
|
Registered User
Joined: Oct 2013
Posts: 4
Likes: 0
The truck is still running good. I also only drive it intermittently because I have a small car for running around with. I've put about 200 miles on since disconnecting and reconnecting the TPS and IACV and no stalling or stumbling since. I'll keep you posted if something changes but fingers crossed.
