Still have issues

[DrrtEgrrT]

So, I have searched high and low to find answers to my haunting problems and have got no where except for in the hole.
90 SHO w/179k on it. The prior owner claims to have done the 60k but im unsure.
The car is lacking serious power. It idles rough and accelerates rough. It has some kind of loud tick coming from the front of the motor possibly more on the driver side. Hard to tell. And a grindy sound coming from under the car when I take off in first gear only for a second then its gone.
Also it seems like it has kind of a hard time taking off from first unless I get the revs up a bit.
I have done - fuel filter, oil/oil filter, plugs and wires, tps, cleaned the maf, put new o2 sensors in, sea foam injector cleaner, lightly flushed the block and have given two oil changes in a few hours driving time just to make sure I got the crap out.
Tomorrow I will clean the IAC and after that I dont know what to do? I do get a CEL only after I drive it for about 5-10 minutes. It does not turn on when idling. Did a KOER test and wouldnt pull a code, but as soon a s I drove away the CEL came back on.
Any help at all would be greatly appreciated.

 

[DrrtEgrrT]

Figured out why I couldnt pull the code, it seems there is 2 wires to hook up to the obd and I could only find one. Can anyone post a pic of where the 2nd smaller plug originates from so I can try and find it? TIA

 

[Irish Pride]

Use this link to check your codes. SHO Phoenix Project Codes

Pull the codes and post up what you find.

 

[DrrtEgrrT]

I cant find the second smaller plug for the obd scanner. Its 30 degrees out, Ill get back at it tomorrow and let you guys know what I find.

 

[DrrtEgrrT]

Pulled codes. 41 and 91. If you reference my original post I have already replaced o2 sensors. Will be checking fuel pressure soon. Any ides yet?

 

[DrrtEgrrT]

Okay so I have next to no fuel pressure at the rails. Is there a relay that could be going bad or fuel pump? Anyone?

 

[DrrtEgrrT]

Replaced fuel pump. Runs better still getting a CEL after driving between 5 and 10 minutes.
Also wanted to comment on this forums awesome involvement in a fellow SHO'ers problems(sarcasm) At least Im doing my own footwork and keeping people posted. Maybe I will help someone else in the end.

 

[DrrtEgrrT]

So replaced the air temperature sensor and am still getting code 41 and 91 (running lean) codes. Think I might try the fuel pressure regulators next. Just running out of money. Wish I could get some help from forum members so I could stop throwing money at this thing. 64 views and 1 response thats not mine??????

 

[SHOdded]

I am sorry you have not received more responses yet. Problem with doing the diagnostics here is too many unknowns at play at this point.

Car's history is unknown, so we don't know what if any mods/repairs have been done. Has the clutch been replaced? Have modified cams been installed? You get the drift.

Ticking can be fuel injectors (normal), or the result of an internal engine problem. Usually, the problem with the MTXs at that mileage will be worn rod bearings, which creates a knocking sound, not a ticking. This shows up as an oil check light later on.

The running rough could be due to wiring that is shorted, so the wiring and connectors should be checked also.

A worn or a performance clutch may required you to hold higher rpms to get going. Performance cams tend to be "lopey" so the car seem to run "rough". Could be worn suspension items/motor mounts that send vibrations through the body instead of absoring them, contributing to the "rough" feeling. Is there a significant loss of power associated with that roughness?

Maybe there's oil in the spark plug wells from leaky gaskets, or even water from rain/driving through high water. Spark plug wires could be easily compromised, spark plugs could be old.

I would also check out the DIS, maybe its faulty in some way (worn connectors, internal short, missing grease on back, etc). Could cause a miss.

I know we have experienced members in Washington/Colorado/Nebraska. The only question is whether you can get to them with the car to take a look at it. It sounds like you have some mechanical inclination/experience? If the usual maintenance items don't help, I'd look into doing the front 60K procedures as outlined on the shophoenix site.

 

[rubydist]

lean on both banks is typically an indication of a vacuum leak in the intake somewhere.

there are a lot of vacuum hoses that are 20 years old now, and therefore you have lots of possible locations for vacuum leaks. you need to very carefully check over all those hoses to make positively sure that none are leaking.

the lack of torque taking off is also an indication of a lean condition. that typically does not refer to a lack of fuel issue, since at lower rpms even a sick fuel pump can keep up. it points again to a likely vacuum leak.

I know 2 days seems like a long time to wait for help when you are beating your head against a wall, but keep in mind that we are all volunteers here and most all of us have real (paying) work to do that keeps us busy...

 

[DrrtEgrrT]

I thank you guys for your response. I know I seemed impatient and probably was. Im just getting to the end of my budget and stressing.
Im going to run thru the intake and see if I can find anything. I can tell the prior owner had it off at one point. Maybe did a half ass job.
I will also run thru the other suggestions and post my results here.
ALso does code 41 and 91 suggest both banks? I was under the assumption it was one side. And last but not least, does anyone have a vacuum diagram? I cant find one any where. Thanks.

 

[rubydist]

41 is lean on rear
91 is lean on front

take a can of starting fluid and carefully spray it on the various vac hoses as the engine idles - the engine speed will kick way up when the spray hits the area where the vac leak is.

 

[DrrtEgrrT]

Im taking a break from the car today. Stressed out. But to comment on rubydist reply, my car only has upstream o2 sensors. Should there be an up and down on it?

 

[SHOdded]

Upstream/downstream sensors started with the OBDII implementations in 1996, so that you would have O2 sensors before AND after each cat. So you are a-ok