Audi#1

I own an manual '91 quattro 2.3 with CISIII , my problem is that when the engine becomes hot (80 C) it lost it's power. Spark plugs looks ok and the idle speed is even but the car have the same acceleration as the city bus ... it looks that the engine have not enough gasoline . When the car is cold everything seems OK... any help?

Seattle Scott

Are you from America? Does the car have a carburetor?

SteveAngry

Do you have problems with Hot starts? How does the car start when the engines warm/cold? How is the idle of the engine when the car is cold/hot? Do you experience loss of power at any other times then when you stated? Does the engine ever stall out on you? Whens the last time you replaced plugs, plug wires, rotor/cap, fuel injectors, etc...

Did you check for any fault codes? Do you even know how to pull fault codes? If not LMK...

Steve Ankney
88 5000
Michigan

Audi#1

Cold or hot the car starts perfectly.The idle is about 2 lines before 1000 rpm (for 2 years is the same), however sometimes when waiting on the intersection the idle is moving for about 1mm up'n down I feel then the car shaking just a little bit.When I hit the gas pedal (with hot engine) on the neutral I see hesitation in the way the rpm increase... and on acceleration the sensation is like somebody presses the brake pedal with the frequency of 2-3 hits\second. The engine never stall out. I noticed that opening the carter (with engine idleing) has no impact. I noticed also that the too high coolant temperature warning light is on after 5-10 minutes of using the car ,the level is ok and it's impossible to warm up the car so quickly with -10c outside temperature ... (Montreal , Canada)
I fill up the 94 octane gasoline and put some Valvoline syntetic fuel treatment . The result ? the car feel a little bit better but it's not 100%
I changed plugs, plug wires,rotor 3 months ago and the fuel filter 2 weeks ago ...

i will check the fault codes this weekend after
I made ''the test light''

Audi#1

Re: Canada , it have fuel injection...

SteveAngry

run the fault codes and LMK what you come up with...

Have you ever changed your fuel injectors? Fuel pump or relay?

Coolant warning light is probably caused by fluid being just a little low. Add a bit and see if it goes away...

Steve Ankney
88 5000
Michigan

Evilclown

All that being done, I would go from there with new fuel injectors. Those CIS jobs like to clog after a while, and don't seem to ever get all the way clean, no matter what you do. Plus, the springs inside them can lose tension, all of which causes them to '****' instead of atmoize the fuel, which would cause the hesitation you're talking about. I'm not guaranteeing new injectors would fix it, but they won't hurt anything. It might also be something as simple as the injector seals leaking air, or another vacuum leak somewhere. Take a can of carburetor cleaner and spray it on the injectors and all over the air intake system. If the idle raises when the carb cleaner hits, you've got an air leak.

Audi#1

no errors on fault codes.... as I expected. Input and output tests are ok. Inever changes the injectors (425$ hmmmmm..)

I have '86 fuel pump installed on it since 1,5 years.

The symptoms were changed since my last post,
actually it works like this: after starting and running all seems ok until the first stop on the lights for example, after 10 and more seconds of ideling the engine losts its power by 30-40% .I found the solution for it , shut off the engine ,turn the ignition twice and start the engine ,it works fine (fuel pump ? I don't think so.) because if waiting on the intersection I maintain the rpm over ~900 it never lost the power. On the other hand I don't know how to increase the RPM on this engine (CIS-E-III) I have ~600. I have the seal under the engine head broken a little bit but I dom't think that it can be the reason of those bad performances after ideling. I can make 50 km ride and if the engine is not ideling too long it works fine

SteveAngry

(Seal under the engine head is broken): Are you talking about the valve cover gasket? Is it leaking oil? I'm not sure what you're trying to describe here...

600 rpm at idle is way to low. Your idle speed setting is way to low. It could be caused by a vacum leak somewhere in the engine. Check all vacum hoses to see if any of them are cracked/rotted. Also it is possible(though not likely) that the bad valve cover is contributing to the vacum leak!

Other things to check:

clean ISV : May be dirty

Differential pressure regulator: pressure may be out of spec...

Uneven fuel distribution: check fuel distributor

System pressure outside of tolerance

Fuel pump: check for delivery rate

fuel injectors

also try running some techron gas additive through the engine. Available at your local VW/Audi dealership under the name Autobahn gas additive. Also available at most stores as Chevron Techron Gas additive...

It might be worth it to you to take it in to a qualified mecahnic and have them check it out...might take a lot of the guess work out of it Sorry I was not more help...

You may want to send an email to: quattro@audifans.com Tell them your problems and that you are not on the list and to respond to you directly at your email. There are alot of knowledgable people there who will be able to help you...

Steve Ankney
88 5000
Holland, Michigan

Audi#1

Ignition coil!!