Power Loss, bad mileage

[stangracr67]

ok, ive been searching the forum for days no to try to figure out what is wrong with my SHO. I just bought it about a week ago as a project. its a 94 ATX with 198 on the clock. seems to be maintained but sat for a bout a year because of a bad brake line. Fixed the brake line and got it running but it runs like crap. feels like its missing at idle. going up throught the rpms if feels like its very underpowered. miss seems to clear up above 2000 rpms. had oil in plug wells. did the upper 60K. new plugs, wires, gaskets, fuel filter. still runs like crap. had my DIS checked. OK. got about 160 miles on the last tank of gas. doesnt smoke. compression was 210-215 on all six. spark plugs didnt look bad when i took them out. only code is 332. when i do the cylinder balance test it is not as rough on #2 just lower idle. any ideas????

also the trans shifts fine except when WOT then it shifts sloooooowly then slams in gear only in the 1-2. Ideas?

 

[frosho]

The 332 code most likely means your EGR ports in the intake are clogged. That will cause a misfire. Here's a how-to for cleaning them out: http://www.shotimes.com/php-bin/mod...le=article&mode=thread&order=0&thold=0&sid=86

A harsh 1-2 shift is somewhat normal.

 

[sperold]

Good advice from Frosho.
If the battery was out of it for awhile, the system has to "reset itself" on a variety of issues like Idle and such. Search for these items on this forum, as you can help it re-learn these things properly.
You can't go wrong with new Motorcraft o2 sensors as well, because they don't issue a code unless they are terrible, meanwhile your gas mileage is the pits.

 

[St Louis SHO]

More than likely needs a t-stat. This will cause the transmission not to lockup, causing crappy mileage. BTDT.

- James

 

[rubydist]

Several other possibilities: the symptoms you describe can also be caused by a sick tps (may or may not set a code), a bad coil pack (usually will set a code), a bad dis (may or may not set a code). Since the dis tested okay, that is less likely.

I would run fuel injector cleaner in the next 3 tanks (or acetone like I use - 5 oz per tank) as the fuel sitting for a year can gum up the injectors and cause them to not fire properly.

Also, just because your plugs and wires are new doesn't mean they are all good. You might need to check the plugs to see that they are all firing okay. Looking at that would also give you an idea on how the injectors are working.

 

[stangracr67]

thanks for all the advice. I will check out the plugs again. is there any way to test the coil pack? cleaned the intake pretty good when it was off, but I will check it out again. I was working on it again today and it sounds almost like a popping in the exhaust. Im pretty sure the motor is solid, has to be something simple. MAF? Fuel pump? The O2 sensors look brand new, dont know what brand. Like I said the motor smooths out at higher rpms just feel like im pulling a 6000 pound trailer.

 

[frosho]

Did you remove the two pipe thread plugs to clean out the EGR ports? That's where it gets gunked up, and it can be pretty tough to clean. I did one for a friend with solvents (Brakleen I think) and a piece of a wire coat hanger. It took a little work, but his misfire was 100% gone afterward. I've heard oven cleaner works pretty well, and throttlebody or carb cleaners probably would too.

 

[llamaking122]

thanks for all the advice. I will check out the plugs again. is there any way to test the coil pack? cleaned the intake pretty good when it was off, but I will check it out again. I was working on it again today and it sounds almost like a popping in the exhaust. Im pretty sure the motor is solid, has to be something simple. MAF? Fuel pump? The O2 sensors look brand new, dont know what brand. Like I said the motor smooths out at higher rpms just feel like im pulling a 6000 pound trailer.

did you take the intake apart? how bout reconnect the vac lines? what plugs are you using? clogged cat maybe?maybe clean the maf. i would go get the codes red. mine doesnt trow codes it jsut gets bad gas milage and it did that thing at higher rpms like you were talking bout. i changed my tstat and its ALOT better. what about your idle whats it at? it only threw cods for koer no koeo or memory codes

 

[Guido0136]

I was working on it again today and it sounds almost like a popping in the exhaust.

Popping??? maybe clogged cat's???

 

[frosho]

Misfires make a popping noise...

 

[stangracr67]

will tackle thermostat and egr cleaning this weekend. hopefully that will help. didnt take the intake apart, just off. no vacuum leaks. autolite 3924PP plugs. no cats. I still think that its weird that on the cyl balance test engine is rough on all cylinders but #2. when it cuts #2 the rpms go down but the engine doesnt shake like the other cylinders. fuel injector? well i'll deal with the thermostat and egr and go from there. Thanks everyone.

 

[stangracr67]

New problem! Cuts out hard above 5500rpms. feels like fuel cut or rev limiter.

 

[stangracr67]

Problem solved!!! Crank Position Sensor was bad. runs great now!