I bought a 1995 discovery at a super low price and it had stalling and idle problems when I got it. It was slightly under powered and the stepper motor seemed to be off and over all it look like it needed a bit of a tune up. Then the Check engine light came on because of a mass air flow sensor issue.

So I bought a new sensor, redid the plugs, wires, oil change, idle control sensor, and took it in to have the stepper re-programmed because it ended up being off.

Everything was pretty solid for 4 months with no issues.

Recently it has been having a slight idle problem. Nothing to worry about except when its cold it will just turn off for a second but then you can immediately restart it and it wont do it again. Also for only a week about one month ago the engine would make a low howling sound when accelerating, also only when it was cold.

I have no idea what that problem can be. the truck is still way under-powered compared to every other discovery I have owned (this is my 4th). I was thinking maybe an issue with the fuel pump, maybe a new distributor cap, clogged fuel filter, fuel injector freaking out. the fact that it runs with out problems after makes me wonder.

Any experiences or ideas would be great.

 

Sounds like a vacuum leak.

 

I did not even think to check that. thanks

 

Do you know how to check for one?
With the engine running spray brake cleaner all around the engine, if the engine speed changes look closer you may have found your leak.

 

I was going to use a vacuum pressure tester. So I should spray it over the hoses or just everywhere around the engine.

 

Spray it anywhere air may leak, hoses, intake, etc.