Techron - too Much?

I’m thinking of adding Techron to my gas.

If I’m already filling up with Texaco/Chevron gas with Techron, would adding more be too much?

No, it wouldn’t be too much.

Are you trying to solve a problem, or cause one?

Nope, no harm done (assuming 1 bottle). Like Tardis said, why do you want to use it?

If it’s already in the gasoline you don’t need to add more.

It won’t hurt anything, but it’s unnecessary.

It won’t hurt the car, but it won’t do any good either. None, nada, zip.

You may, however, start to believe your wallet is leaking.

It won’t hurt the car, but it won’t do any good either.


Care to diagnose?

1995 T-100 Base Model - 2WD, 4 cyl 2.7L engine, 5 spd, Std cab
199,500 miles
Tune-up stuff: new distributor cap & rotor, new wires, new plugs, new air & fuel filters, new PCV valve, and of course regular oil changes with Toyota filters & synthetic blend oil (NO DIFFERENCE DECTECTED).

Over the past 3 years, it has been getting more difficult to start when it is warm.
In the past two months, I have had to (when warm) start it and get the RPMs up to 2K or so to keep it from stalling. In the past month, the idle has been high, then low - basically inconsistent. Once running, it does not stall and accelerates ok. Current gas mileage is around 20 MPG - not it’s best (22-23) but not horrendous.

Have only begun (past two years) to use top-tier gas.

So - I’m thinking I have one or more dirty injectors, but I’m not sure. I’ve heard that Techron cleans them - but enough?

Some other possbilities include leaking injectors and/or a bad fuel pressure regulator and/or a vacuum leak.

Sounds like a vacuum leak or idle air control issue. Fuel injector cleaner is probably not going to help. It doesn’t fix broken stuff.

Hmmm. Have checked all the vacuum connections - they’re all good, hoses look good.

A leaking injector? Where would it leak, how can you identify it?

That the idle is inconsistent - high at times, low at times - suggests in my mind that something is sticking a bit?

Nothing lasts forever…

Amen to that.

Check the throttle plenum for oily carbon buildup, Clean it out with spray carb. cleaner and an old toothbrush and rags.

Excellent problem description. I wish you’d posted the problem up front.

Difficult to start when warm combined with erratic idle suggests a few different possibilities. One is an ignition component becoming heat sensitive. I’d include in that the coil (pack?) and the igniter. The best way to troubleshoot this is to have it hooked up to a scope and use a heat gun judiciously if necessary. But, lacking that, a timing light with an inductive pickup and a heat gun might get you the information you need. Hook up the light, warm up the indiividual suspects one at a time, and see if you can induce erratic operation.

One other possibility that comes to mind is a bad oxygen sensor. I believe the '95’s only had upstream sensors and OBDI systems. When the engine is cold, the oxygen sensor loop is bypassed to allow the engine to run rich. Once at temp, the O2 sensor is back in the equation. A bad O2 sensor could cause problems when warm but not when cold.

Another is the already mentioned vacuum leak.

As already suggested, checking the fuel pressure and the regulator might be enlightening also.

Check the EGR system out too, although that should also make itself evident when cold as well as when warm. If the valve isn’t closing you’ll be getting exhaust in the instream at idle and that can cause rough idling.

Looks like it’s time to swap out a vacuum line. Yep, one was loose. As soon as I reattached it, the engine would start much easier when warm.

The idle issue continues - sometimes it seems to idle high, and sometimes it idles low and a bit rough.

Will break 200K miles tomorrow.