joe cat

Rough idle on start when car is hot on 91 auto. With 96,000k

When its cold its perfect !!!!!!!!!!!

Right after i shut it down and re start -Its PERFECT!!

If I drive it 20 minutes or one hour (does not seem to matter, I just need to get the car hot) .... I go into a store spend 20 minutes- come out and start the car...

It starts but the idle goes down and up and then down and up and of course the oil pressure as well and then the dash lights flicker and sometimes it stalls - If it stalls I re start it and just play with the gas to make it not stall untill it clears itself.

I did try the wd40 trick once. To no avail.

Yesterday for the first time I put two bottles of techron in the car. The car got much snappier and even shifts better- love the techron-

This was all happening BEFORE the techron as well. I only drove the car 60 miles with the techron gas- do you think I would have to drive it more to get the complete effect of the techron- Maybe that will solve my problem??


Any help would be appreciated!
Joe Cat


A picture is enclosed for your viewing pleasure

S4ordie

60 miles means you probably have only burned 3-4 galoons of gas with the diluted Techron. Ya gotta run through the entire tank for all of the 'magic' to happen. Sort of like taking one pill out of a bottle of 30.

Mrmerlin

lots of engine starts and stops will let the Techron work better than one long trip.
Your problems sound like either leaking damper/or fuel pressure regulator.
To test pull off each vacuum line and smell the line if it smells like gas then its probably leaking ,also pull a vacuum on them to see if they hold .
Leaking injectors , Techron may fix this
Leaking check valve at the fuel pump, Techron may fix this

Hoops88S4

Sounds very similar to what my 88 is doing. But it doesnt seem to matter whether it is cold or hot, tempermental woman that she is. LOL. What is the Techron solution?

S4ordie

Techron is a fuel additive developed by Chevron-Mobil. It is a fuel system cleaner you pour in the fuel tank that you can buy at any auto parts store. I use it in all of my vehicles just before every oil change - in case some of it makes it way into the oil system. Don't want the lubricating qualities of the oil to be diminished.

I have had pretty good luck with regular use of Techron but if your problem(s) is/are heavy carbon build up on valves, pistons, etc. then a professional application of BG products, or other similar strong cleaners, can make a significant difference. Remember this stuff will not cure electrical or sensor malfunctioning issues.

S4ordie

Hmmmm, how? I always assumed it was better to run the engine continuously to keep the application of the additive consistent and thereby more effective. Meaning I usually put the Techron in the tank just before heading out for a long drive. Is there any published information about how to make fuel additives most effective relative to engine use? Thanks for any information you have on this. I'd like to know what is best.

Mrmerlin

Dan its simple once the cleaner has been added to the fuel system, drive the car for a short trip then shut it off.
This lets the cleaner soak on the parts while things are hot , go for another short drive and then let it sit, after numerous short drives the cleaner will begin to loosen and dissolve the parts that have deposits in them.
While you may think that a long drive would be better the fuel additive will simply be used up B4 it has a chance to work

joe cat

I personally called chevron on their 800 number on the bottle as they have Proguard, with techron and fuel injector cleaner, and fuel system clean, and concentrated plus fuel system cleaner.

The most shocking part- SOMEONE PICKED UP THE PHONE- A REAL PERSON!!! RIGHT FROM THE START!!
Transfered me to a Gent Mike in Technical- And he said best bang for your buck is the concentrated plus fuel system cleaner- "has the highest concentration of the Secret ingredient". Best way to use it is 1 ounce per gallon - He also said if you put more your wasting your money.

Like any other car guy i argued and said come' on It wont be a smidgen better if i double it to two ounces- per dallon- - he said, staight out- BUDDY, TIMES ARE SLOW RIGHT NOW, AND I WOULD LOVE TO TELL YOU TO DOUBLE THE DOSE- BUT HONESTLY IT DOES ZERO MORE!!!- YOUR WASTING YOUR MONEY! Also any less reduces the WOW effect as well- The sweet spot for cuing is 1 ounce per gallon".

Joe Cat

S4ordie

Thanks for the info. Doesn't this stuff, like fuel, evaporate pretty quickly? Hard for me to think it loads up on the back of a super heated valve wet and dripping with fuel and additive. I would think the high temp would dissipate any remnant pretty quickly, hence my previous thinking driving a long distance would mean a continuous steady application of the cleaner. Not trying to debate here, just offering up what my thinking has been for many years. Doesn't mean it is correct. Might need to call Joe Cat's buddy at Techron for their recommendation.

I do know that intermittent and rapid acceleration is a good way to break up carbon, sometime, on pistons and valves. Perhaps this process combined with fuel additives is the right thing to do.

Mrmerlin

the techron is a heavier fluid than the fuel, it does mix with it though.
Letting it soak in the fuel injectors and the other parts of the intake system will have a better effect than just having it pass through

joe cat

leaking damper/or fuel pressure regulator.
To test pull off each vacuum line and smell the line if it smells like gas then its probably leaking ,also pull a vacuum on them to see if they hold .

Where do I find all of that and any special tools needed,-- Joe Cat

Hoops88S4

thanks for the info!

SteveG

This may help.

http://members.rennlist.com/v1uhoh/underthe.htm

joe cat

Steve G, Thank you so much. That was very nice of you.

Hopefully one day I can return the favor. I do import export if that helps!
Joe Cat

Mike B

Joe, have you released / explored the possible tension of the flex plate? I ask as automatic transmissions have a disturbing pattern of thrust bearing failure. I mention this not to alarm you, but to make you aware...this is speaking from experience.