Hi guys, this is pretty embarrassing but I thought I would share my latest hiccup on the 40 this past weekend in hopes that it may help someone else that was having similar issues.
A few weeks ago I randomly had a big loss of power and the truck would not get above 45 mph. Started sputtering extremely bad and would not idle unless I helped it.
I initially thought to look towards a fuel related issue. Clear plastic fuel filter was only a 1/4 full but each time I looked at the sight glass in the carb it was in the middle of the window. (I rebuilt the carb last year with the aisin rebuild kit). I still against better judgement thought that it was still fuel related and did the fuel pump test, cranked the truck for 15 seconds and it pumped roughly half a cup in that time so that seemed fine. fuel pressure was close to 5psi. So the pump seemed to check out fine. I took the top piece off of the carburetor and cleanout out the bowl and all of the jests and passageways even though they all looked clean.
I had an extra fuel filter so I threw a new one on and it still had the same symptoms. I have the power steering pump bracket from JT Outfitters on in (AWFUL product. Alignment is off by a landslide do to the machining of the bracket where it bolts to the top of the head.) It wears down the belt extremely quickly so I took it off and decided to desmog the truck at the same time due to the smog pump making a grinding noise. When i desmogged everything i noticed one of the vacuum lines had come loose but i attributed this to me working around in that area and i moved on.
When i got it all back together and took it out for a test drive the truck ran amazing. Tons of power and absolutely no sputtering. the next day i was driving it and the same symptoms came back. again i started looking at fuel issues but sight glass was full right where it was supposed to be. I then started to think that it could be spark related but the truck ran good at low rpms but would just fall on its face when you tried to get into it. This is where my stupidity was luckily nipped in the butt.
I pulled my vacuum gauge tester and when i was going to hook it up to the manifold i noticed the same vacuum line had popped off again. (same one that i hooked up the week prior after i noticed it was running bad) I looked into this further and the end of the vacuum line was slightly cracked and did not make a snug fit to the nipple. I cut about 1/2" off of it, put it back and threw a zip tie on it and cinched it down good and took it out for another drive. It's been two days and truck is back to running amazing. All along it was just the vacuum line sliding off and in turn this created a HUGE vacuum leak which made the truck not want to idle and run extremely poorly upon heavy acceleration and highway speeds.
It makes sense now because i would assume that it had such a large vacuum leak that it would not allow the carburetor to operate properly. Anyways Even though i feel dumb for this hopefully this will help others if they have similar symptoms.
Check your vacuum lines!!
ALSO - I know there are lots of writeups on desmogging a 2F but i never found a thread that had a ton of pictures clearly showing which lines to disconnect and which ones to keep. If y'all would like i can grab some pictures and post a writeup on desmogging my 1978 2f.
A few weeks ago I randomly had a big loss of power and the truck would not get above 45 mph. Started sputtering extremely bad and would not idle unless I helped it.
I initially thought to look towards a fuel related issue. Clear plastic fuel filter was only a 1/4 full but each time I looked at the sight glass in the carb it was in the middle of the window. (I rebuilt the carb last year with the aisin rebuild kit). I still against better judgement thought that it was still fuel related and did the fuel pump test, cranked the truck for 15 seconds and it pumped roughly half a cup in that time so that seemed fine. fuel pressure was close to 5psi. So the pump seemed to check out fine. I took the top piece off of the carburetor and cleanout out the bowl and all of the jests and passageways even though they all looked clean.
I had an extra fuel filter so I threw a new one on and it still had the same symptoms. I have the power steering pump bracket from JT Outfitters on in (AWFUL product. Alignment is off by a landslide do to the machining of the bracket where it bolts to the top of the head.) It wears down the belt extremely quickly so I took it off and decided to desmog the truck at the same time due to the smog pump making a grinding noise. When i desmogged everything i noticed one of the vacuum lines had come loose but i attributed this to me working around in that area and i moved on.
When i got it all back together and took it out for a test drive the truck ran amazing. Tons of power and absolutely no sputtering. the next day i was driving it and the same symptoms came back. again i started looking at fuel issues but sight glass was full right where it was supposed to be. I then started to think that it could be spark related but the truck ran good at low rpms but would just fall on its face when you tried to get into it. This is where my stupidity was luckily nipped in the butt.
I pulled my vacuum gauge tester and when i was going to hook it up to the manifold i noticed the same vacuum line had popped off again. (same one that i hooked up the week prior after i noticed it was running bad) I looked into this further and the end of the vacuum line was slightly cracked and did not make a snug fit to the nipple. I cut about 1/2" off of it, put it back and threw a zip tie on it and cinched it down good and took it out for another drive. It's been two days and truck is back to running amazing. All along it was just the vacuum line sliding off and in turn this created a HUGE vacuum leak which made the truck not want to idle and run extremely poorly upon heavy acceleration and highway speeds.
It makes sense now because i would assume that it had such a large vacuum leak that it would not allow the carburetor to operate properly. Anyways Even though i feel dumb for this hopefully this will help others if they have similar symptoms.
Check your vacuum lines!!
ALSO - I know there are lots of writeups on desmogging a 2F but i never found a thread that had a ton of pictures clearly showing which lines to disconnect and which ones to keep. If y'all would like i can grab some pictures and post a writeup on desmogging my 1978 2f.
