'85 SR5 HORRIBLE fuel mileage...TURTCEL

[TURTCEL]

So I have been going rounds with my Terc for a few weeks now. I had to disconnect the fuel cut solenoid (A) and the EBCV because they were both causing runability issues for me at 1800 to 2300 RPM's. I can not track down any other issues that may be causing my problems other than a possible internal vacuum leak on the carb.

I swapped a good carb on to the car from Petros for diagnostic purposes with no luck, same issues (tells me it's not in the carb). I also swapped the computer, EBCV and fuel solenoid A out with known good units too with no luck.

With having the EBCV and fuel solenoid A disconnected and plugged the car runs fine but gets horrible fuel mileage. I mean like 22 MPG...way low from what it used to be. I understand that these components affect my fuel leaning while decelerating but I can not get the car to run well with them connected. I can not find any other vacuum leaks or bad components. Am I overlooking something? What could be in line to these components that could potentially causing them to seem bad but could be good or is there an unrelated potential problem that someone may be aware of.

It truly sucks going from 32 MPG to 22 MPG. Any help would be so appreciated.

Peace

[ARCHINSTL]

I realize you've probably already perused the record-setting thread I started back in '05 about this 1800-2300 RPM cycling situation I had. https://tercel4wd.com/forums/viewtopic.php?t=1372
After fighting that for three years with the OE carb, a reman carb, and another reman carb (first reman had an unrelated prob), I just gave up and installed the Weber. I would hasten to add I tried absolutely everything without solving the prob.
My experience was identical with yours - save for the horrible mileage; mine was just a tad less than what I get with the Weber (perhaps 25-6 v. 27-9).
Maybe the prob lay with the computer - but the FSM ignores it totally - and I don't think anyone here ever reported messing with it.
If your state will let you - ditch the OE.
Tom M.

[TURTCEL]

Tom,

I have actually read your post many times...starting back in Idaho and now in Seattle. It is where I got the idea of disconnecting mine, which got rid of my 2000 RPM surging. The EBCV only recently gave me troubles. Funny thing is I have tried 2 good EBCV before eliminating it completely because it seams that something in the system is activating it and Solenoid A at all times.

I have changed the computer with one out of a good running same model Terc but with no luck.

I have been on the fence about a WEBER for a while now and since WA State exempts vehicles from SMOG testing at 25 years and older I am in the clear for the WEBER. When I was in Cali early this year with plans of staying I was worried about SMOG testing down there since I knew the car had some slight issues. My only concerns with the WEBER is that my wife is going to be driving it with our son during the winter and I have heard they can ice up sometimes, I don't want there to be an accident from it not running in the winter. And I like to go to the mountains but I live at sea level most of the time. How will the car run at those altitude differences?

Peace

[dlb]

there is always lots of discussion about different jet sizes for the weber but by and large, most people have found they run excellently right out of the box with the stock jets at a wide variety of altitudes. i am almost at sea level and the stock jets were fine for me. that same car is now over by the rockies with the same jets in the weber and i've heard of no problems with it.

i had lots of problems with the weber icing every morning on my drive to work in the winter. it doesn't last long though, and there is a simple way around it: start the car 5 or 10 minutes before you want to leave in the morning, let the car run at high idle for 1 or 2 minutes, then shut it off. as long as you leave shortly after that, the residual heat from running will warm the carb body up past the point of icing, and you won't have to waste as much as gas as you would letting the car idle until the engine is fully up to temp. i've heard of guys with old motorcycles doing the same thing.

i'm a big believer in the stock carbs so i encourage you to keep looking for answers to your stock carb problems but hopefully that info will help you if you do decide to go the weber route.

[TURTCEL]

I plug a block heater in at night during the winter. Should that help with the carb icing issue? Also, do I have to remove the carb heating spacer with a WEBER? Can it still be used to keep the carb from icing?

Peace

[dlb]

some folks have been able to fit the spacer between the carb and manifold, some have not. seems like it might depend on how worn the engine mounts are but you can test that on your own easily enough.

neither the spacer or a block heater will keep the weber from icing because neither keeps the carb body from cooling down when it starts sucking cold air. you just have to wait for the warmth from the engine to warm the carb. a block heater may get you past the point of icing sooner though, since the engine would take less time to get up to temp.

[marlinh]

Carb ice is independent of engine temperature. It occurs under certain conditions in cool wet weather. As the air passes through the venturi of the carb, it speeds up and cools. If the moisture content of the air is ideal, it will freeze in the throat of the carb. That is why the flex hose coming up from the exhaust manifold is important.

[ARCHINSTL]

I've never knowingly had a prob with carb icing with the Weber.
That said - the St. Louis Metro area runs only between 465 and 700 feet in elevation. The coldest we ordinarily get in Winter is very occasionally a tad below Zero, but usually around 10-15º, so the cold has not been a prob.
We have killer humidity in the Summer, but the Winter is usually pretty dry.
In the cold, starting has been no prob - I just let the car warm for a minute or two and then gently take off.
I don't know which jets the Weber has - I told Carbs Direct the elevation here, but dunno if it replaced them.
Tom M.

[marlinh]

You probably don't get the right weather conditions for carb ice where you live. I had it happen to me with an old Datsun pickup that I drove many years ago. I started losing power and then the truck stalled. I coasted to a stop and pulled off the air cleaner and there was ice in the barrel of the carb. After a few minutes it melted and I was on my way again.

Also, with the Weber drawing air from the engine compartment, carb ice is not as likely.