Rough Idle

OK here we go........2000 Pontiac sunfire gt 2.4 litre engine 180 000 Km Rough idle started suddenly one morning......things ive tried and tested.....changed spark plugs twice replace throttle body gasket replaced intake manifold gasket tried new coils checked engine compression all between 216-222 psi checked engine vacuum not steady but between 14-15" mercury added two cans combustion chamber cleaner no check engine soon light!!!my GM mechanic had it for three hours could not find anything added one can injector cleaner thing i havent checked evap egr catalityc converter fuel pressure engine idles rough only, when it gets above 1500 rpm it disappears but it takes longer than usual to come back to idle speed , all this happens hot or cold....... Hope you can help or suggest............Rick Answer: Your problem you say is below 1500 rpm and that the vehicle runs fine above 1500 rpm. I would say you need to replace the I A C valve (idle air control). The I A C only functions at or below 1500 rpm. This is a common issue with GM engines. If you have replaced the intake manifold gasket , this should be fairly simple for you. Also when you remove the old I A C clean any excessive carbon that may be present. Let me know of your progress.

wrangler is overheating and has an entire new cooling system.

Question:

wrangler Jeep 4.0, my 94 wrangler is overheating and has an entire new cooling system. it now is idling rough and stalls out. whats wrong? replaced the entire cooling system. was fine for a month now it overheats again and idles rough and dies

Answer;

This is a classic sign of a blown head gasket. To confirm this, have a compression test done. All cylinders should be within 20 psi of each other. If not, you have a blown head gasket. Have the head check for cracks once removed to be on the safe side.

Overheating Diagnostics

Lost power and wouldn't go faster than 50 mph.

Question: I have a 2000 Ford Mustang 6 cylinder. Twice it has lost power and wouldn't go faster than 50 mph. It then starts running correctly. It has been in two different shops and I've been told nothing is wrong. Any ideas on the problem? Already Tried: Replaced the fuel filter, ran diagnostics and no errors reported Answer: It is possible that your fuel pump may be not pumping enough pressure when it gets hot or when doing this concern. What you need to do first is get a fuel pressure reading if possible when this occurs. This will tell a lot about what is going on. If you find that the fuel pressure is low, below 30 psi and does not rise as you snap the throttle, your fuel pump is not operating properly. If it does OK, I might suggest taking it to the dealer, I know it cost a little more but they have a better scan tool to look at all pids, sensors and injectors and ect., and can see what is going on. If they can't make it do it at that time, they can install a ,what we call a flight recorder, and when the problem happens, you mash a button and it will record data and they can see what went on.

How to replace idle control valve 1993 Honda accord

Question:

What is the problem of up and down idling on my motor when its became hot on my 1993 Honda Accord.

Answer:

Could be one of two things. Either the IAC valve or the fast idle valve. Both are located on the intake manifold. Right next the the fuel rail. I would suspect the fast idle valve first because it controls the idle once the car is warmed up.

Induction Service

In just the past few months I have been presented with a number of estimates given to my customers from dealerships that have performed warranty or recall work. On each estimate the dealer claims that the vehicle is in need of "Induction System Service". I have been asked by several people what this service is and if they really need to have it done. INDUCTION SYSTEM SERVICE: The Induction Service consists of removing the throttle body and cleaning the inside or throat of the throttle body. This allows a smoother flow of the required amount of air. DO I NEED IT: The Service can help aid in the correct idle if you are having this issue or looking to prevent it. In most cases if your car is running fine, you are not required to have this service done. It is however, a good preventative measure.

Rough Idle

Question : OK here we go........2000 Pontiac sunfire gt 2.4 litre engine 180 000 Kmrough idle started suddenly one morning......things ive tried and tested.....changed sparkplugs twicereplaced throttlebody gasketreplaced intake manifold gaskettried new coilschecked engine compression all between 216-222 psichecked engine vacuum not steady but between 14-15" mercuryadded two cans combustion chamber cleanerno check engine soon light!!!my GM mechanic had it for three hours could not find anythingadded one can injector cleanerthing i havent checkedevapegrcatalityc converterfuel pressureengine idles rough only, when it gets above 1500 rpm it dissappears but it takes longer than usual to come back to idle speed , all this happens hot or cold....... Hope you can help or suggest Response to question: Your problem you say is below 1500 rpm and that the vehicle runs fine above 1500 rpm. I would say you need to replace the I A C valve (idle air control). The I A C only functions at or below 1500 rpm. This is a common issue with GM engines. If you have replaced the intake manifold gasket , this should be fairly simple for you. Also when you remove the old I A C clean any excessive carbon that may be present. information from www.freeautomechanic.com