Dies after high speed and/or prolonged run time.

General discussion about our beloved Tercel 4WD cars
Post Reply
User avatar
Cadendoo22
Member
Posts: 29
Joined: Sat Sep 25, 2021 11:57 pm
My tercel:: 1983 Toyota tercel sr5 4wd

Dies after high speed and/or prolonged run time.

Post by Cadendoo22 »

I have a bizarre issue with my fueling system that I'm stumped with. It started at first with kind of a rare sputter at full throttle where it felt like it wasn't getting enough fuel, it only lasted a second or two then went away. I took it to the Utah Gambler 500 and as we were running through the trails it did this sputter a little more frequently, then further up the trail it sputtered and died. After spraying a bunch of starting fluid onto the carb it started again and kept going for another 20 ish minutes and died again. It kept this pattern of run for 20 then die, and then start with fluid about 3 or 4 times. At the time I thought the fuel was vapor locking in between the fuel filter and the carburetor (A Weber 32/36) so I tried to insulate the fuel lines against heat. I tried taking the car up the freeway and it died about halfway to the destination in the same way. So I tried more fixes to get the heat down still thinking it was vapor locking. After another time of stranding me on the freeway I decided to fix the vapor lock once and for all and installed an electric fuel pump to cycle fuel constantly. Thinking this would for sure fix my problem I tried taking it to another Gambler 500 event 3 hours away and got stranded about 30 minutes into the trip. While in the process of trying to get the car started again I noticed that the transparent fuel filter that is mounted on the firewall wasn't filling with fuel, implying that the fuel in the tank wasn't getting to the carb. I went to the local O'Reilly's and bought another fuel filter hoping that maybe I had a clogged filter. After installing the filter the car started and the filter filled with fuel like normal and then after idling for about 2 minutes the filter stopped filling and the car died. The filter wouldn't get fuel with the stock mechanical fuel pump or my installed electric one, but if I let it sit for about 20 minutes it would start up and run for another 20 or 30 and die again. I've been driving it really calmly around town in about 5 to 10 minute trips and haven't had an issue. The only thing I can think of that would cause this issue would be a rusty tank, a leaky fuel line, or the tank not venting air properly. The old fuel filter was really clean and I've never had issues filling up the tank at a gas station. This issue is a little over my head so I'm sorry for the long post I just wanted to get as much information in as possible.
User avatar
dlb
Highest Ranking Member
Posts: 7305
Joined: Mon Jul 06, 2009 9:03 pm
My tercel:: '87 sr5, '83 dlx parts car
Location: bc, canada

Re: Dies after high speed and/or prolonged run time.

Post by dlb »

Cadendoo22 wrote: Wed Nov 09, 2022 11:54 pm a rusty tank...or the tank not venting air properly.
Those are the things I was thinking as I read your post. If you have a scope I would drain the fuel tank and put the scope down to have a look. I would also replace the gas cap, and try blowing out the breather lines on the tank with compressed air.

For the record, since I joined this forum about 13 years ago I have heard people talk about vapor lock lots, but I don't recall anyone actually ever having it occur. I'm not saying it can't or doesn't, I just think it's one of those things that is far more rare than a lot of people believe. So any time I hear about fuel delivery issues, vapor lock is way down on my list of suspected culprits.
User avatar
rer233
Highest Ranking Member
Posts: 1013
Joined: Sat Jan 01, 2011 1:49 pm
My tercel:: Multiple

Re: Dies after high speed and/or prolonged run time.

Post by rer233 »

I agree with dlb- don't think it's vapor lock. I've posted here before on how to diagnose your problem- I'd provide a link, but can't (too stupid!) Just do a search on "aux fuel tank" and it'll come up. Good Luck!
if it aint there, there's a good chance it won't break!
83 SR5 Silver/Blue (Snowmobile/work beater)-totaled but drivable
85 SR5 Blue
88 SR5 White (the 'good' one)-not anymore-totaled
87 fwd silver wagon a/t
87 4wd dx Cream (a/t- not anymore- now m/t)
User avatar
Nordical25
Top Notch Member
Posts: 307
Joined: Tue Feb 08, 2022 11:49 pm
My tercel:: 2 4wd 1987's. One with 4a, other with 3a
Location: Finland

Re: Dies after high speed and/or prolonged run time.

Post by Nordical25 »

I have an idea. Could you make a fuel tank from soda bottle and see if it runs flawlessly? You just take an empty Pepsi/Coke bottle, fill it with petrol and put both fuel lines from fuel pump to bottle and see how motor runs.

If it runs now flawlessly, your fuel lines + fuel tank need further inspection. If it won't run still, you have problem at fuel pump + carburetor + intake manifold section.

Doing this helps to understand origin of problem.
User avatar
Cadendoo22
Member
Posts: 29
Joined: Sat Sep 25, 2021 11:57 pm
My tercel:: 1983 Toyota tercel sr5 4wd

Re: Dies after high speed and/or prolonged run time.

Post by Cadendoo22 »

Nordical25 wrote: Thu Nov 10, 2022 11:07 am I have an idea. Could you make a fuel tank from soda bottle and see if it runs flawlessly? You just take an empty Pepsi/Coke bottle, fill it with petrol and put both fuel lines from fuel pump to bottle and see how motor runs.

If it runs now flawlessly, your fuel lines + fuel tank need further inspection. If it won't run still, you have problem at fuel pump + carburetor + intake manifold section.

Doing this helps to understand origin of problem.
It's not a bad idea the only problem is I don't have a way of testing reliably to see if the problem is solved.
User avatar
Cadendoo22
Member
Posts: 29
Joined: Sat Sep 25, 2021 11:57 pm
My tercel:: 1983 Toyota tercel sr5 4wd

Re: Dies after high speed and/or prolonged run time.

Post by Cadendoo22 »

rer233 wrote: Thu Nov 10, 2022 8:55 am I agree with dlb- don't think it's vapor lock. I've posted here before on how to diagnose your problem- I'd provide a link, but can't (too stupid!) Just do a search on "aux fuel tank" and it'll come up. Good Luck!
Yeah I think I've ruled out vapor lock. I read a post you responded to back in 2014 and it seems the guy had the same issue as me and it was solved by replacing a cracked line so that's the way I'm leaning right now.
User avatar
Cadendoo22
Member
Posts: 29
Joined: Sat Sep 25, 2021 11:57 pm
My tercel:: 1983 Toyota tercel sr5 4wd

Re: Dies after high speed and/or prolonged run time.

Post by Cadendoo22 »

I unplugged my fuel line from the carb and watched my electric fuel pump drain into a gas can and the flow looked ok, maybe a few bubbles so I replaced all the rubber fuel lines in the engine bay and now it won't pull any fuel from the tank at all. So I'm thinking I need to drop the tank tomorrow and see if the rubber lines to that are leaking? I'll check the tank too and see how it looks
User avatar
Petros
Highest Ranking Member
Posts: 11930
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: Dies after high speed and/or prolonged run time.

Post by Petros »

metal lines can get corrosion pits that allow air to get sucked into the fuel line as it runs. so do not overlook inspecting the metal fuel lines as well. I assume you have replaced the fuel filter, and checked the screen at the fuel line inlet to the carb.

it is fairly easy to check the fuel pick up in the tank, it is under a metal hatch under the carpet in the cargo area. remove the hatch and than first clean out the Philips screws on the fuel tank cover so you can get a good grip on the screws. remove the tank cover and lift out the fuel pickup and the sender attached to the cover. you should be able to inspect the inside the of the tank with a strong flash light, for deposits, rust or debris. and the inlet screen, as well as the condition of the fuel lines over the top of the fuel tank. do it outside and be mindful of anything with an open flame or sparks when you have the hatch off the fuel tank.

good luck.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
Post Reply