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Roy, import/domestic specialest
Category: Car
Satisfied Customers: 6168
Experience:  ASE master tech for 40 years
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F350 7.3 powerstroke: I am in Australia and have a 96 7.3 which

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I am in Australia and have a 96 7.3 which misses at start up and then the idles smoothes out after 10-15 minutes. It will then be good until left overnight and the problem is there again the next morning. Could it be a poor injector?
Good morning, my name is XXXXX XXXXX I will assist you.

Yes, it could be an injector which is common but in order to find the miss, do you have a scan tool to see which cylinder???

Before condemning the injector, a more common issue is the valve cover gasket as the electrical connector for the injectors goes through that point and could be causing a bad connection. I would look there first to be sure there is no issue at that point.

Customer: replied 4 years ago.

The auto electrician has checked the gasket and connections electrically and it tests OK. The issue I have is why the miss disappears after a short time. if it was a faulty injector would the miss not be there continuously.

did he remove the valve cover to check the connection on the inside of the gaskets??? That a big job on its own.

It depends on the spray pattern of the injector. It can be intermittent.

Customer: replied 4 years ago.

yes the valve covers were off and I believe he checked it inside the cover. The mechanic also commented that there was not a return oil flow from the injector. would you suggest that I replace all the injectors to be sure or only the single unit.

you could replace just the bad one but did your guy find out which one has failed?? Replacing them all is always a recommendation but very costly.

Customer: replied 4 years ago.

none appear to have failed electrically but one cylinder is running colder than the others so we think that is the one that is down. I still do not understand why it gets going after a short period of time.

It is from the make up of the injector and the extremely small orfices that are in them. Any build up of carbon or any other debris will change the spray patterns to effect cold operation.

Customer: replied 4 years ago.

Thanks for your help. would a engine flush help with getting the carbon removed or is the only option to remove the injector and replace.


Thanks for al your help

you can try the flush. It is always good to clean it up but as far as the injector. you cannot get into the injector with the flush. Try some diesel injector cleaner and see if that helps before doing the injector.

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