chevron techron and 4.0

over the last 6 months or so, my jeep has developed a stumble a idle, so i tried the usual list of things, replacing plugs, MAP sensor, etc, looking for a problem. I then tried running a bottle of chevron techron injector cleaner though it, and it IMMEDIATELY drove perfectly, no stumble, no hesitation, nothing. this continuted until the next fillup. After i filled the tank again, maybe a week later, the problem returned, not quite as bad as before, but definitely the same thing. a few fills later, back to before.

SO i gathered that it wasn't the injector cleaning that fixed the problem, but rather the burning of the cleaner made it run better. is there a good reason for this, and does anyone have any ideas on what problem it could have? i suppose i can run a bottle of techron on every fillup, but that doesn't seem like it should be necessary...

you need to PM RichP. Find one of his posts and click on it. He's the local Techron Guru. I tried some to, but I didn't have any problems and it ran better. He also presuaded my to go to Mobil -1 synth, and I've been happy with the change.

He might be able to guide you through the problem.

So far, I've had good luck using Techron ... but I didn't have the same problem you're having. Periodically, my 4.0HO, when starting, will fire okay but then quicky stalls out like it's starving for fuel. It starts right back up and runs fine ... but it definitely shouldn't do this.

After running a tank full of Techron, the problem goes away for about 10K-15K miles ... then slowly returns over time. More than likely it's the injectors.

Keep in mind my injectors are all original ... with 160K miles !

Another thing you might try is changing out the fuel filter located under the chassis... there may be a bunch of junk in it that keeps clogging up the injectors---could be the root cause and explanation why it runs okay with Techron additive, then reverts back to old ways. Dirty gas ?

Good luck with it.

This sounds really simplistic, but . . . try a different brand of gas. Although the octane rating may be the same, the actual calculation of octane rating is dependent on many variables. Two gasolines of identical octane rating may be very different and will perform differently in the same engine. FWIW My 88 Beretta would hardly run on ARCO fuel, but ran like a champ (well, as good as the 2.8 L engine ever ran) on Texaco, Shell, 76, etc.).

I used to use Arco gas so i could save money driving over 150 miles to work and back, but it rusted out my manifold runined my O2, cat and my TBI fuel injector on my AMC's 2.5. I buy 76 Gas exclusively now since its made with ethenol (made from corn and is mtbe free) which increases gas mileage since it burns more efficiantly, cleaner and makes more horsepower then MTBE fuels which are oxegenated to burn cleaner but MTBE is more poisionus to the enviroment, thats why its going to be phased out here in Cali.

Matt