OBD1 / 1FZ-FE Troubleshooting Help!

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
Well, I think it was the VAF... Went for a drive today and didn't miss a beat and ran like a champ. Not sure why someone would have wanted to richen it up that much. :homer:
 

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
I'm back... Think the VAF clocking was definitely part of it. But with the warmer weather started noticing the "Acceleration Enrichment" being stuck on in TOYOBD1. When it was stuck on, it would ping and buck pretty hard if I did not catch it in time. Swapped back to the newer ECU and went to the post office and HD with no issues so far.
 

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
Well, that was short lived :mad::poop:
 

White Stripe

Hard Core 4+
Joined
May 5, 2015
Messages
1,354
Location
Milky way galaxy
Might be worth buying a wide band air fuel ratio gauge and installing. Then you can see what your air fuel ratios are. See if they change when low on power. Does the TPS make a full sweep when you cycle it with key on engine off in live data? Did you replace the knock sensors Yet? Curious how it would run with the knock sensors unplugged as well although I've never tried running with them unplugged.
 

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
Might be worth buying a wide band air fuel ratio gauge and installing. Then you can see what your air fuel ratios are. See if they change when low on power. Does the TPS make a full sweep when you cycle it with key on engine off in live data? Did you replace the knock sensors Yet? Curious how it would run with the knock sensors unplugged as well although I've never tried running with them unplugged.

I have not replaced the knock sensors yet... Just dragging my feet plus moved a few weeks ago, so everything is still in various stages of disarray. Guess I could just unplug them to see what happens.

TPS always responds according to TOYOBD reader. Only thing I have noticed is that when it acts up, the AE appears to be "stuck" on. Not sure what exactly the AE does, but I am guessing at least part of it is to apply full voltage to the fuel pump. After dinner and weed-eating was going to look at the FSM.
 

White Stripe

Hard Core 4+
Joined
May 5, 2015
Messages
1,354
Location
Milky way galaxy
I have not replaced the knock sensors yet... Just dragging my feet plus moved a few weeks ago, so everything is still in various stages of disarray. Guess I could just unplug them to see what happens.

TPS always responds according to TOYOBD reader. Only thing I have noticed is that when it acts up, the AE appears to be "stuck" on. Not sure what exactly the AE does, but I am guessing at least part of it is to apply full voltage to the fuel pump. After dinner and weed-eating was going to look at the FSM.
I'm not sure what AE does. Maybe it forces open loop and a richer fuel mixture. This is the wideband I've used on a few vehicles fyi. It's been great for diagnosis and tells u the exact air fuel ratio at all times.
https://www.ebay.com/itm/WB-D2-Digi...c82ef96bf41bd8324b2865caabfba&redirect=mobile
 

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
Totally over this @#$+&*. Tried to drive up to Chinn's lake and can't make it, hopefully I can get back home.

Anyone around today or this weekend possibly want to come look at it?
 

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
Fuel pressure checks out. Right at 44psi / 37psi when regulated.

The pump never gets 12v except when starting. I can manually ground the leg that goes to the ECU and it will get 12v, but the ECU is not triggering it for some reason.

I have an extra VAF coming from Steamboat, but that checks out as well from all of the FSM tests.

One thing I noticed is that the return fuel line looks like soda it has so many air bubbles in it. Seems like an issue to me, no leaks that I can see in the lines though.
 

rover67

Rising Sun Member
Joined
Nov 1, 2007
Messages
9,803
Location
Boulder, Co
I keep reading your updates and just shaking my head with no real ideas anymore...

I do keep brainstorming.. promise.

how did you observe the fuel return? mainly just curious.

I need to start from the beginning here and read again..
 

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
I keep reading your updates and just shaking my head with no real ideas anymore...

I do keep brainstorming.. promise.

how did you observe the fuel return? mainly just curious.

I need to start from the beginning here and read again..

I disconnected the line to the tank and hooked up the clear vent line from the tester and just had it dump into a container.

I have new soft lines and fuel filter that will be here tomorrow.
 

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
New-to-me VAF arrived today, installed and it does seem like it runs a little better. But it is also nice and cool out.

Fuel pump still only gets 8.4-9.0v except when starting or right after I shut it off.

My paper FSM was supposed to be here today, but looks like like it will not arrive until next week now. Not able to find when, why or what triggers the fuel pump to get 12v... Hopefully it is in there, somewhere.
 

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
Welp... no idea what did it. But it appears that you have to be in the throttle pretty good and >3000rpm for it to kick up to 12v.

Things I did:
Checked readout on TPS (ie. unplugged it, think this might have been it)
Checked wire between COR and FPR
Checked wire between EFI Relay and COR

Things are in all kinds of disarray, so going to put bolt them back up one by one and see if maybe there is a short, or if there was just a bum connection on the TPS.

[edit]
Should also note that I have unplugged the COR, EFI and FPR countless times through all of this.
[/edit]
 
Last edited:

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
FSM has arrived.

Took her for a spin today to the Murphy station in Brighton for a fill up. To say that I am hesitant is a bit of an understatement, but I think I might be able to put this behind me. Made it there and back, plus a trip to the Post Office an hour or so later. Both of which would not have been possible a week ago.

No "smoking gun", which doesn't sit well with me. But she is running better than it ever has before. It never wanted to rev beyond 3000rpm and now will keep pulling. No hiccups, no stumbles, not down on power.

🤞

Maybe 7777 was lucky after all...

IMG_20200623_144010.jpg
 

IoN6

Rising Sun Member
Joined
Sep 2, 2019
Messages
1,461
Location
Arvada
Ran up to Chinn's lake yesterday and then down to Centennial last night. Cruiser has never run this good since I have owned it. Actually passed some people on the uphill grades on 70. I think part of it was the VAF, I have no idea in what way or why it was messed with before. I also think the one of the wires to the TPS might have had a bad connection. It actually down shifts fairly respectably now.

Either way, glad to put this behind me after 3 years. Thanks for the help and putting up with my rants!
 
Back
Top