OBD1 code 44, but mostly fine
05-26-2018, 06:49 PM
#1
OBD1 code 44, but mostly fine
Hello,
87 Ford F150XL 302 EFI, been chasing codes to get a poorly running vehicle almost there: EGR (and controler), TPS got her running for a day then had a crank-no-start. No fuel pressure at the rails. New fuel pump relay+fuel filter and putting gas in the rear tank (I suspect the pump in the front is intermittently weak, the rear is needed to keep the high pressure pump primed) got her going with fuel pressure back to 34-40 on both thanks. I'll post more on fuel pressure/tanks later. The truck is a tad low on power, sound just a bit rough but was fine on freeway ride. Came back and ran codes. KOEF was all 11's. Engine on with hitting the throttle gave code 44. I am posting because the other ones here also had idle issues and code 12. I don't have that. What would be the best diagnostic path to take? Any order of checks? I did just pick up a manifold vacuum gauge:>)
Thanks much!
87 Ford F150XL 302 EFI, been chasing codes to get a poorly running vehicle almost there: EGR (and controler), TPS got her running for a day then had a crank-no-start. No fuel pressure at the rails. New fuel pump relay+fuel filter and putting gas in the rear tank (I suspect the pump in the front is intermittently weak, the rear is needed to keep the high pressure pump primed) got her going with fuel pressure back to 34-40 on both thanks. I'll post more on fuel pressure/tanks later. The truck is a tad low on power, sound just a bit rough but was fine on freeway ride. Came back and ran codes. KOEF was all 11's. Engine on with hitting the throttle gave code 44. I am posting because the other ones here also had idle issues and code 12. I don't have that. What would be the best diagnostic path to take? Any order of checks? I did just pick up a manifold vacuum gauge:>)
Thanks much!
Last edited by oldgranola; 05-26-2018 at 06:51 PM.
05-27-2018, 12:26 PM
#2
Member
Join Date: Jan 2018
Location: Memphis, TN, Earth, Milky Way
Posts: 11,256
Received 1,731 Likes
on
1,487 Posts
The first step is ALWAYS to confirm that the indicated condition actually exists.
When you post codes, post the COMPLETE definition for each.
(phone app link)
When you post codes, post the COMPLETE definition for each.
(phone app link)
05-27-2018, 03:57 PM
#3
Thanks Steve. Your phone app link isn't readable on this computer. So how would I test if the condition is true? In my Sunpro tester's manual published 1994, code 44 is frustratingly simply "Problems in Thermactor Air control System". To me thats like saying "it smells funny". Further reading elsewhere informs me that the TAS is/was required on all 5L+ engines as a means of optimising emission control of hydrocarbons. It is a computer controlled system of valves, air pump, tubes, and sensors (looks hard to get to) that injects fresh air into different parts of the exhaust system at different points ahead of the catalytic converter. I don't have to pass emissions on this anymore in WA and to me the exhaust looks and smells the same as my much younger explorer. But I wonder if TAS malfunction can effect performance? If not, its not a priority. However....
This diagram TAS first posted on "stagnet" makes it look like it may indeed harm or be a co-result of other perfomance reducing problems. If I can find it, I'm sure there's at least one vacuum line I should be testing.
This diagram TAS first posted on "stagnet" makes it look like it may indeed harm or be a co-result of other perfomance reducing problems. If I can find it, I'm sure there's at least one vacuum line I should be testing.
Last edited by oldgranola; 05-27-2018 at 04:01 PM.
05-28-2018, 12:09 PM
#4
Member
Join Date: Jan 2018
Location: Memphis, TN, Earth, Milky Way
Posts: 11,256
Received 1,731 Likes
on
1,487 Posts
Click the "phone app link" text below the thumbnail. But if you're using a real browser on a real computer, clicking the thumbnail should open a new tab with a big image & caption below.
Generic scantools have generic code lists; use the list in that caption, which is specific to these trucks. EEC-IV scantools are notoriously UNreliable, anyway - you should confirm that code by reading them with a jumper wire, as linked in that caption.
The 2ndry air system was required on all engines from '87-95. This caption explains it:
(phone app link)
Whether your locality checks emissions or not, it's illegal & counterproductive to remove, disable, or abandon the systems. The engine will run best if you maintain it - ALL of it.
There aren't many vacuum lines on the truck, so it's worth inspecting all of them:
(phone app link)
Generic scantools have generic code lists; use the list in that caption, which is specific to these trucks. EEC-IV scantools are notoriously UNreliable, anyway - you should confirm that code by reading them with a jumper wire, as linked in that caption.
The 2ndry air system was required on all engines from '87-95. This caption explains it:
(phone app link)
Whether your locality checks emissions or not, it's illegal & counterproductive to remove, disable, or abandon the systems. The engine will run best if you maintain it - ALL of it.
There aren't many vacuum lines on the truck, so it's worth inspecting all of them:
(phone app link)
