struggles around 2-3000 RPM, knocking valves, timing belt

[thegoon543]

My '92 XLT runs like a charm. However, whenever I'm driving and the engine gets to around 2000 rpms, it seems to struggle to go any higher. When it gets past 3000, its fine, but in between, it seems as if its gasping for air. I know the air filter is fine because i just put a new K&N in about a month ago. Also, there is a problem with the valves knocking. Right now I use 87 grade gas, and I know using high test gasoline helps it out. However, I can't keep buying it because its so expensive and a waste just to keep my valves from knocking. It knocks mostly when i'm out in the highway. Finally, are there telltale signs of when the timing belt needs to be changed?? Thanks.

Chas McMillan
'92 XLT
"Dreams are like fish, you got to keep on reelin'"
-G. Love and Special Sauce

 

[Alec]

As for the knocking, try running a fuel injection cleaner to clean the injectors and valves out. I've heard auto tranny fluid actually works very well. Do you have any other power mods besides the K&N? I know when I put mine in along with the exhaust, I had to use 89 octane because of the increased airflow (now I use 93). Also, many people with older Explorers have to use higher octane just because of engine age.

 

[thegoon543]

How does the auto transmission fluid help? I've never heard of anyone using that to fix it, but I'm always open for suggestions. As of now, I dont have any other mods besides the K&N, but im planning a tune up and get some bosch +4s in there. I might try using the 89 gas as opposed to the 87. However, if that's what solves the problem, i dunno how long i can afford to put 89 or 93 in it. Thanks.

 

[Alec]

Auto tranny fluid is mentioned in the thread titled "seafoam"

If that doesn't help (which it will at least partially) try running 89. If 89 doesn't fix it, don't go to 93, it probably won't do anything. Then it's time to find other causes.

 

[SteveVB]

Chas, couple of things.

Might want to pull the plugs and check for carbon build up, may have a leaky intake letting oil into the combustion chamber. The intakes on the OHV's seem to be prone to leaking, both vacuum leaks and oil into the chambers. The carbon build up could cause your knocking. A few other things I would check would be the fuel filter, Fuel pressure Regulator, and the throttle position sensor.

The V-6s in the Explorer dont have a timing belt, it uses a roller chain which should be good for a couple hundred thousand miles. If you mean the accessory belt on the front of the engine I change it every 50K.

 

[espnfreak]

I cleaned my fuel injectors and am getting just a rough acceleration. its just loud and sounds like my engine is making more banging noises than anything else