Problem in High Gear

[zingi4532]

I have a problem with my 90 5.0 that started a few month ago. When I'm cruising on the freeway in 5th and mash down the gas, the engine seems to "stumble", it did not use to do this. It kind of feels like it's missing but it only does it in 4th and 5th under WOT. Cruising aroung normaly, it seems like it has normal power- the problem is only in high gear. Do you guys have any suggestions?

 

[HISSIN50]

have you pulled codes? i would pay attention to the EGR. good luck.

 

[battyice]

Is your engine in good tune? Neglected ignition components like plug wires & the cap & rotor can cause problems like you're describing.

 

[zingi4532]

The engine is in great shape. It only has 82k on it. I did a tune up a few month ago. I put in an accel cap & rotor, FMS 9mm plug wires, new plugs and a new egr sensor to pass emissions. i pulled the codes at that time to see why my check engine light was coming on and when i changed out that sensor the light went off- i haven't gotten any check engine lights since. The car has 3.55's and a new FMS wcT-5, aluminum drive shaft, High flow air filter and bbk pullies. Do you guys think it's the fuel filter- somebody mentioned that. What kind of plugs/gap do you guys go with cause i'm thinking of changing out the rapid fires that are in there right now. Any other suggestions would be greatly appreciated.

 

[281pony]

my car has done similar things and a fuel filter has been a temporary fix. its an easy thing to replace, has it ever been replaced before? i would try that.

for 89 and 90 my chilton says .044 gap, but for 91-93 its saying .054

 

[zingi4532]

The fuel filter has not been changed in a few years- that sounds like a likely problem- I'll replace that and see what happens; btw what kind of spark plugs do you guys like to use on a stock motor

 

[rock88gt]

Are you still using stock injectors? If you have bigger injectors you may need a better fuel pump or just adjust your fuel pressure. Are you sure it's the engine and not your transmission slipping?

 

[HISSIN50]

btw what kind of spark plugs do you guys like to use on a stock motor

autolite 25's for me. Motorcrafts are good too. some folks have had problems with platinums (just something to remember if you try some and have issues).

good luck.

 

[281pony]

i use autolites also.