Sho experts...help!

[93stocksho]

alright guys,

I have a problem with my car. The car has no low end power. it bogs from idle to 3000 then it takes off. When i step on the gas I can hear this sudden sucking noise coming from the tb/MAf. There is a momentary lag in throttle response due to this sudden sucking, like it can't get enough air. This is different to the normal airbox noise you get from SHO's. I replaced the MAF, no difference. I ran with the MAF unplugged, no difference. I changed computers, no difference. I ran the codes, no bad codes. also, my tail pipes seem to have some black exaust residue. I'm at a loss guys, help!!

 

[Mr Anonymous]

Secondaries staying open? Vacuum leak?

 

[twr]

I would second the secondaries being open. Verify that the secondaries are closing on start up. If not there is a little black barrel shaped canister on the back of the intake. Check the vacuum hoses to it and the electrical connector as well.

 

[93stocksho]

They are definatly closed. I can see them open and close when some one revs the engine in neutral, and I can hear them open at 4000rpm when driving.

 

[SHOYourYama]

Bad plugs/wires? shrug

 

[philw349]

An old/bad Throttle Position Sensor (TPS) may contribute to that cause that, it happened in a much milder form to my car. It's a $23 part at autozone, and they can even test it out for you before you buy it to see if its bad. The best part is its very easy to access.

 

[revhardSHO]

Bad plugs/wires?

yes, i think that may be it. How many miles on the wires? You should only be using the motorcraft double-platnium plugs

good luck

 

[93stocksho]

The plugs and wires are stock. How would they contribute to this: strange sucking sound/delayed throttle response/lack of low end power/ lots of top end power?

 

[It's SHO Time]

My friends car is doing that to and he check the fuel pressure and found out his is the fuel pump, check yours cause it sounds like your having the same problem as my fried. Well good look on finding the problem and keep me posted.

Justin

 

[SHOYourYama]

Bad wires arc and ground anywhere on the engine causing power loss; run the car in the dark and mist (not saturate) water over the engine, see anything??

I had no low end power in my SHO, replaced those factory plugs and wires, and had instant return of low end power.

shrug

 

[93stocksho]

anyone else have the loud sucking sound as the tb butterfies open? also delayed throttle response?

 

[89 black SHO mtx]

shrug is it sucking or blowing??? do oyou still have a good brake booster or is your brake pedal getting hard to push?? possibly a stopped up cat. the black is oil in your tail pipes or fuel. you could try loosening your y pipe from the manifolds and then run it. or you could take it to a muffler shop and have them do a backpressure test on it. other than that everybody else had some good ideas. the wires could cause excess fuel which will burn a cat up in a hurry. shrug

 

[93stocksho]

Sucking. I can see the hose from the MAF to the TB suck in a little bit.

 

[89 black SHO mtx]

changed your air filter lately???? hows about something stuck in the air box or in the fresh air tube in front of the filter??? you shouldn't have that much pull there unless there is a restriction. try opening the air box up and see if that helps any! or you could just have a weak air tube and its closing up on you

 

[93stocksho]

I have a new K & N filter. It makes this sucking noise even if I dis-connect the MAF from the airbox. and as you know, I have a brand new stuck MAF that had no effect. I like the exhaust theory....I'm going to get that checked out tomorrow.

 

[Mike Kopstain]

The black on the tips is actually an indication of a rich mixture, which could have clogged up your cats.

Food for thought, I suppose.

 

[93stocksho]

if it's running rich, how do I lean it out?

 

[Mr Anonymous]

93stocksho:
if it's running rich, how do I lean it out?

Proper maintenance.

 

[Mike Kopstain]

SHOooo:

93stocksho:
if it's running rich, how do I lean it out?

Proper maintenance.

Chris is right. Don't worry about leaning it out. Fix the problem rather than the symptom and you'll find that you have the car running right in no time.

 

[billyshoe]

hey, are you guys really experts?