help!! problem

hi, i just recently bought a used 98 blazer with a 4.3, but when i get on the gas there is a loud clicking sound repeadly until i let off the accelerator, also its been very sluggish when accelerating and the rpms will actually rise and fall slightly on the tach(also you could be hear the engine) this happens mainly on the highway any speed about 35. the service engine soon light will come on for a day or two at a time and when going up hills the light will flash on and off. even when the light goes off these prolems still persist. i am not sure if its a sensor, the trans itself or who knows. I have not put the car on a scanner yet but i plan on it this weekend when i am off from work, any good idea you could give me i thank you in advance,

You're in the right direction getting it scanned first...saves alot of needlessly spent monies...I would check the shroud around the fan for the ticking...could be a worn motor mount, this causes the engine to shift slightly and the fan could be catching the shroud...If you just bought it and can afford to spend an extra 20$ pick up a Haynes or Chilton manual for it, money well spent...As for it being sluggish..get the codes first, could be anything from a converter to just a good tune up..

Are you saying the check engine light is staying on and flashing while driving??? if so that is bad real bad stop and have it scaned asap before it is damaged

well the ses light comes and goes some, it will be there for 2 days, and than the light disappears, But when the light is on, and i come to a hill and i get on the gas to keep speed up the suv will sputter and the light will start flashing, also i noticed when the car is in 3 this tends to stop, but when its in drive and i am on the highway it happens, its not during town driving, i am going to have autozone scan the car tomm for me, hopefully i will be able to provide some codes that u will be familiar with, but i thank you both so far.

The light blinking means damage is being done to the emission system

My rotor clicks when my engine is cold. After my first acceleration it goes away though.

flashing light is usually a misfire. try doing a full tune up.

right that means damage is being done to the emissions system /cat

Please go to autozone and let them pull the codes... They are stored than we can be more specific with the problem

ok i took the vehicle to autozone today, they said the codes pulled said both banks are running rich, and that there is a misfire in 4, i called my mechanic and he said probably just needs a full tune-up and that will fix the codes with the 02 also, is this true or do u have any other suggestions, and again thank you all for ur advice in advance

You probably want to go back and get the EXACT codes. They might just be feeding you a line of BS.

There are knowledgable people here that can tell you what is wrong if they knew what the real codes are.

-Skeeter6755

Yip, we need the EXACT codes. Not some autozone monkey's explanation of what they are.

If both 02 sensors are running bad, and there is a misfire on #4, more than likely your #4 injector is bad or stuck open (this will account for the enriched condition) and needs to be delt with. I agree with the others though that you should get the exact code numbers.

true, but having cylinder #4 stuck open will not explain having both banks running rich.

This sounds like a dirty MAF sensor.

Dirty MAF will not cause a blinking check engine light only a steady light

Yes it will, just helped a guy fix his.

A blinking light is the sign of a major multiple misfire. It was caused by a dirty MAF that was not sensing properly and was screwing up the measurements and the air:fuel ratio constantly.

learn something new every day

If it isn't that, it is the coil arcing problem seen on 1996+ 4.3L's.

With a dirty MAF you will even get O2 sensor codes constantly. This same guy replaced his whole O2 sensor system including all the sensors only to find out that the damn MAF was screwing the whole system.