99 4.6l Running Rough

[andyhaas]

I have a 99 EB 4.6l 135,000 miles. Att 100,000 replaced the spark plugs and wires. Just cleaned the throttle body a week ago, replaced the air filter, oil chg, fuel filter, etc.

The truck skips and seems to miss. I though the throttle body clean would fix that, the thing was all gummed up.

I have always used 87 octain gas and when i add a bottle of fuel injector cleaner the engine seems to run better. Bad injector? Is that hard to trouble shoot without codes (no check engine light yet). I hate to take it to the dealer or mechanic and let them parts swap.

I have bought a can of electronics cleaner, i planned to clean the MAF sensor in inside by the air cleaner.

Any ideas?

 

[braduardo]

How long has it been doing this? It might not hurt to run a can of seafoam through it. How did you clean the throttle body?

 

[andyhaas]

It did it for a while last summer and I can't remember how they fixed it. this time for about a month.

I removed the upper throttle body and using 2 cans of cleaner, baby bottle brushes and some elbow grease I cleaned out the ports that go to the one sensor.

I can look into seafoam.

 

[andyhaas]

WOW you can pour Seafoam into just about any orifice in the truck, huh? I bought a can and put it in last night (gas tank). I have only driven to work (20 miles) so time will tell.

At lwast once in the past I have had a bad fuel injector. Is diagnosing that hit or miss?

 

[SPreston2001]

You get the best results from Seafoam when you inject it through your brake booster line. Adding it to the fuel tank does clean injectors and stuff, but you almost feel an instant difference when you add it through your booster line. Plus thats how you get the famous Seafoam cloud of smoke!!