'86 SR5 Carb and Choke Quandary.....

[ARCHINSTL]

OK - bear with me for a minute..............

I was able to fix the no power from 1K to 2K RPM problem by installing an unbroken TVSV a while back. However, the engine is dying when the accelerator is touched from idle (800+ RPM) to 2K until it is thoroughly warm. When it starts to die, the options are to immediately goose it above 2K or let it die down to 300 or so, at which point it will self-revive to 800. This, of course, makes immediate driving awkward. When warm, it runs pretty well.

This next may seem dumb, but my only real experience with carbs was with the SU as used on most BritMobiles years ago as well as Volvos in the 50s and 60s. This was pre-smog, of course, and the SU was a very easy carb to comprehend and tune (it also used a manual choke-yeah!). I presume, as the Owner's Manual states, that when the accelerator is pressed twice, the choke is closed and a fast idle cam is engaged. Well, on my carb that does not happen, whether by the pedal or by moving the throttle quadrant by hand. Nothing seems "broken", per se, but there is just no engagement of a cam or movement of the choke shaft/linkage. So far the starting has been instantaneous, but then the o/s temps have been in the 90s for some time, so it's not exactly "cold" starting.

So - I'm listing what I've done thus far and request an opinion (or two or three or more):

> New (Bosch) plugs and cable
> New Bosch oxygen sensor
> New fuel pump, filter, and all fuel lines inside the bay
> New air filter
> New TVSV
> All 40+ vac lines replaced
> All diaphragms checked by "oral vacuum" and they (seem to) work
> HAI device in snorkel reconnected-someone had disengaged the operating rod from the flap
> New manifold/snorkel hot air tube
> Totally clogged EGR valve and delivery pipe removed and scoured clean
> Three new lower carb gaskets (last mech did not use gaskets on either side of the heat shield-just sealer).
> All carb pivots, etc. cleaned, but carb not rebuilt
> Did not remove the little fuel window and clean-forgot-not clear what the fuel level is-the window is pretty cloudy
> HCV cleaned/lubed on i/s side of manifolds and seems pretty free-moving
> Idle, fast idle, and TP position checked and (slightly) adjusted, per the FSM

Additionally, has anyone replaced the Aisan regular choke with a manual unit? AZ, et al, havethese "universal cable units" for not much $, and it does seem like a simple fix - advice?

Thanks to all - and have a Glorious 4th, as they say...
Tom M.

[arbskynxnex]

If you adjusted the float level you may have lost a spring. I did on mine (either the pump plunger or power piston, I can't remember which) and it gave me those symptoms. The fuel mixture could also be off. Maybe too rich?
I don't belive the choke linkage should move while messing with the throttle. It is automatic and has a little bi-metal heater that controls the position of the choke. If the choke is closed when cold, and opens when warm (I remember 130 degrees F being the magic number, but that could be me) I'd think its ok. I went through the whole carb rebuild deal and if you unhooked linkage it is really easy to hook it back up funny and get some odd results. You have to look at the FSM reeeaallllyyyy closely since the drawings suck. I hooked every thing up on mine and it idled at 3700rpm, turned out I "misadjusted" <_< my linkage.

[ARCHINSTL]

Arb - Thanks for the reply.
Actually, while I removed the carb, I did not open it up or try a rebuild - yet. I removed it to install the three mounting gaskets and to retorque the manifold gaskets, as takza and Adelard had suggested in previous posts, as well as to attempt to rehab the HCV on the manifold. I did clean the o/s and i/s, of course, and all of the pivots.

On my '88 Dodge 2.6 carbed p/up, initially tapping the accelerator partially closes the choke and ups the idle on a cam. Toyota's OM and the FSM (which I have) state that touching the pedal "sets the choke and fast idle", which should mean that they are initially set until the heat from the choke coil takes over, similar to the Dodge. I did not unhook any linkage in my ministrations.

I have just noticed that there are air bubbles in the fuel filter (new), and wonder if that could be a part of the prob? The filter on the p/up is impossible to monitor because of its location, and the Britmobiles had an integral filter in the pump. The gas cap is new, and the bubbles persist even with the filler's flap kept open - could one of the old hoses at the tank have holes? However, I just do not know if the bubbles are normal. Some do appear to be sucked up into the pipe leading to the (new) pump.

Incidentally, the Dodge (actually a Mitsu) FSM is FAR better and clearer than the $86 Toy FSM, which was a bit of a disappointment. I agree with your critique of the drawings, and have relied on Autozone's photos almost more; I would recommend AZ's site for its Repair Guide section, which is model specific and quite comprehensive.
Tom M.

[takza]

Guess your choke doesn't work? I have a manual choke kit I got from JCWhitney...but haven't installed it.

You could have a pinhole leak in the suction line from the tank to the pump...but I doubt those small bubbles would cause much trouble....yet.