SHO running like SHIT!!

[Silver Bullet]

Hey everyone... I am experiencing a problem that just started recently after adding a can of "B-12 Chemtool" cleaner to my gas. I have a 93 SHO "ATX" W/112,000 miles on it. I was told by a friend that the stuff thoroughly cleans out your intake valves, fuel injectors, combustion chamber, plugs, etc. I ran a full tank through last week, and decided to run another one through this week to assure maximum cleaning. It ran absolutely perfect up until this afternoons display. Well... I went to start the car today, and it fired up and died. It did this four more times!! Then I tried holding the gas pedal down, and it VERY slowly and roughly came up to speed. It would not maintain idle if I took my foot off the gas. I had to hold it at 3000 rpm for approx 2 1'2 min just to get it where it wouldn't stall. It totally ran like crap on the highway during my commute to work too. Any ideas what is happening under the hood guys?? A guy at work suggests I run the rest of this tank with "B-12" in it down, and then stick with straight gas for a bit. Any ideas or suggestions are appreciated... Take care

<small>[ March 21, 2003, 07:56 PM: Message edited by: Silver Bullet ]</small>

 

[jasonty]

Hmm... How much B-12 did you add and how much gasoline was in the tank?

 

[Mr Anonymous]

Codes???????

 

[NotSoSlowSHO]

SHOooo:
Codes???????

ditto...


one thing I can think of right now is that the additional can might have eroded and dislodged some gasoline sludge at the bottom of your tank and now your injectors are gummed up... shrug

 

[Silver Bullet]

I had a full tank both times, and added a full can too. The only code that the computer spit out was for the "EGR" pressure sensor... I hear that is a common problem on the SHO's. I am hoping that after I run the tank out everything will be . I just want my baby to come back to life again!! I hope the injectors aren't clogged... Shouldn't the fuel filter catch the sludge before it can get to the injectors?? I just had a brand new fuel filter installed too.

* I think I will stop trying to fix things that aren't broken

<small>[ March 21, 2003, 09:24 PM: Message edited by: Silver Bullet ]</small>

 

[SHO_Driver]

Put a fuel pressure reader on the schrader valve, if the reading is too high your injectors could be clogged, if its too low you need to look at the lines, filter and pump.

It might clear up after running the tank dry and refilling.

 

[Mr Anonymous]

Could you more accurately describe 'running like crap'? Check your plugs and wires, and you should try running the KOER tests, including a cyl. bal. test.

 

[jasonty]

I agree with the fuel pressure check. Try checking the fuel pressure. It should be at about 35-40 psi at the schrader valve. If it's higher then that, change your fuel filter. That may solve a restriction problem, but if not, you may have an injector clogged. If the pressure is too low, you might want to think about replacing your fuel pump. I think if you change out your filter and run a tank of gas without additives through the system you should be ok. Good luck. Oh, one more thing, if your EGR is stuck open, your car will run like dirty ass.

<small>[ March 22, 2003, 12:27 PM: Message edited by: jasonty ]</small>

 

[Silver Bullet]

First of all... Thanks for the reply's. I describe "running like crap" as a shaking feeling that I believed was coming off the engine at approx 65-70mph on the highway W/ a lack of power. It just did not seem smooth like it usually runs at all... Like it was actually working to keep speed, when usually it cruises there. The next "EXTREMELY" weird thing that happened this afternoon, was when I went to a self car wash. I pulled up to the bay, and got out with the car running... As I passed the front of the car heading towards the change machine my ears picked up on a rapping noise!! I was like "OHH NO"--> My car did not just go there... I popped the hood and it seemed like it was on the top of the engine (Near the back middle of the intake manifold) as you're standing in front of the car. I stopped at Midas Muffler shop because that was the only place that was open at the time, and I go there frequently. The mechanics said it was a weird rap sound, and guessed it was probably either a lifter or an injector. On my ride home I stopped at Mcdonalds (My favorite place now)--> Trunk blew off there. When I came back out to the car and fired it up, the sound was absolutely gone as if it never was there at all?? Even the midas mechanic said it was loud enough that he heard it as I pulled up to the shop while he was still in the bay... If that was a bad lifter rapping that loud, it wouldn't just quiet down and become silent would it?? The car rode perfect to work tonight also... The check engine light is still coming on and off frequently too. I think it's messing with my head!! Take care guys, and any thoughts are always appreciated...

<small>[ March 22, 2003, 11:36 PM: Message edited by: Silver Bullet ]</small>

 

[Mr Anonymous]

Well, I doubt it's a lifter since the SHO is a DOHC motor and uses hydraulic valve tappets...

Anyway... Did the tapping change with the throttle? Did it sound like metal-on-metal? Did you put your hand on the motor while this was happening and 'feel' the tapping?

Presuming the tapping was indeed coming from the top of the motor, a few possibilities come to mind:

- A timing chain or chain tensioner problem.

- A broken valve spring.

- A shim that has been ejected from its bucket.

You might also want to use the 'broomstick' test to check your cats, although I don't think that would explain the tapping, but it might explain the power loss/rough running problems.

You're in MA, so I would recommend having either Erik T. or Fred H. see if they can give you a hand diagnosing the problem.

 

[Silver Bullet]

I just showed a mechanic at my work (I work third shift) my engine, and he said it sounded awesome... He wishes his sounded that good he said!! I hadn't though about it until he mentioned it, but two weeks ago I added some of that CD2 oil detergent to my oil, and he suggested that it may have dislodged some sludge that blocked a passage way shortly and then worked it's way out. THAT'S IT!! I'm changing the oil tomorrow, and there will be absolutely no more additives added to my engine whatsoever. I'm taking the "If it's not broke, don't fix it" point of view from now on.

Adding cleaners to a perfectly running engine= tool

<small>[ March 23, 2003, 12:06 AM: Message edited by: Silver Bullet ]</small>

 

[shojuan]

SHOooo:
since the SHO is a DOHC motor and uses hydraulic valve tappets...

Hydraulic valve tappets?? No it doesn't. Must have been a slip of the tongue because you mention the shims later on.

 

[Mr Anonymous]

shojuan:

SHOooo:
since the SHO is a DOHC motor and uses hydraulic valve tappets...

Hydraulic valve tappets?? No it doesn't. Must have been a slip of the tongue because you mention the shims later on.

Sleeping in front of the PC again, I meant bucket valve tappets... ZZZZZzzzzzz.....

 

[RBade]

If you added the fuel system cleaner after you filled the tank, that is your problem. I did that once, and I too, ran like crap. The stuffs got to get mixed with the gas as the gas fills the tank.

 

[haydenm315]

shojuan:

SHOooo:
since the SHO is a DOHC motor and uses hydraulic valve tappets...

Hydraulic valve tappets?? No it doesn't. Must have been a slip of the tongue because you mention the shims later on.

gotta be a slip. No hydraulcs here. woooooooh woooohhh!!!!!

 

[RStalveyARFF]

most of the detergent stuff is best to be added right before you're going to change the oil. It's not supposed to be used for long periods of time, well at least most detergents.