VIDEO: Fuel Pressure? Bad Cutout at WOT

[IM Buddy8]

http://files.filefront.com/100+0528MOV/;12036110;/fileinfo.html

That is the video if you give it full throttle quickly it will cut out you will see as the video progresses how it acts. I'm thinking either fuel pressure, cam sensor, or PCM? I need to fix this asap because it's not so easy to drive like this.. Any help or input is greatly appreciated. Thanks

Any questions just ask and I can get another vid if necessary also.

 

[clindahl]

Do you have any codes? Is this an MTX or ATX? What Year? How many miles?

 

[Phoenix]

First of all , you need to pull the codes before you go any further.

Heres how: http://www.shophoenixproject.com/eec/eec.htm

 

[shoshirtsandhat]

Swap out the MAf sensor with one from a known good running SHO

 

[IM Buddy8]

Got codes for TPS.. TPS was swapped.. twice from 2 good running cars. MAF was also swapped from a good running car.. I have a few other codes I'll find them right now in one of my previous posts..


122- Throttle Position (TP) sensor
- Signal voltage is too low.
I swapped the TPS with my other car and it didn't change anything and it still shows the code\

112- Air Charge Temperature (ACT) sensor - signal voltage is too low.

This is where the beeps got confusing and I got this out of it..

2 1 2 2 2 2 (Usually it repeats it's self but it did these two in a row only once)

If these are codes it trying to tell me

212-Loss of ignition Diagnostic Monitor (IDM) Signal - short to ground in spark output (SPOUT) Circuit.

222- Distributorless Ignition System (DIS) problem - Loss of right side Ignition Diagnostic Monitor (IDM) signal.

Also I have a video of actual driving
http://files.filefront.com/100+0500M.../fileinfo.html

 

[yzstud]

have u done any work to it recently?
212 points to crank sensor
222 points to coil pack

if u have a spare coil pack, try swapping it

 

[IM Buddy8]

I added a thank you for you yzstud because I've made this thread a few times now and haven't got ANY other info besides MAF.. Until now. I can get my hands on a coilpack even though I just sold my other car I could of easily swapped with I'll do this asap tho so I can keep this tread active and I'll let you all know how it works. Any other ideas let me know.. I'm gonna check fuel pressure also very soon. Thanks

 

[Storm-Chaser]

Also have the voltage output of the generator checked. Low voltage output (as well as high) can result in all kinds of eroneous sensor-based codes, as well as cause symptoms of a weak coil pack (ignition cutout at high rpm due to weak spark).

If that's not the problem, the TPS code may be related to the TPS harness-lead (versus the TPS itself), which has been a known issue for the SHO.

 

[IM Buddy8]

Also have the voltage output of the generator checked. Low voltage output (as well as high) can result in all kinds of eroneous sensor-based codes, as well as cause symptoms of a weak coil pack (ignition cutout at high rpm due to weak spark).

If that's not the problem, the TPS code may be related to the TPS harness-lead (versus the TPS itself), which has been a known issue for the SHO.

someone did a tape job on one of the wires coming from my alternator.. like when someone changed it at some point they did a hack job with the wiring. what should the output be like 14.4? or something.. I honestly forget exactly what it's supposed to be..

Also I don't have cutout at high RPM as soon as I hit about 2600 rpm's I can floor it no problem but below that I can't give it more then an eigth of a pedal or else it feels like spark just is gone..

And when you say the TPS harness-lead do you mean all of the wires that go to it just make sure they are ok? I don't wanna take all the insulation off of the wires but I might just have to if I don't see any obvious wire damage on the outside.

I'm picking up a coilpack tomorrow afternoon also so I'll try that out. I got tomorrow off so get the ideas flowin so I can try to get it running right! Thanks for the help I still have things to try if anyone has input please post

 

[Storm-Chaser]

Remove the tape and inspect the harness-leads. Look for frays, corrosion, or bad connections/crimps/soldier joints.

Voltage output should be 13.5v to 14.5v. Amperage output is dependent on what year SHO you have (which you still haven't posted).

Many of the OBD sensors use resistance or voltage feedback to provide information to the ECM.

someone did a tape job on one of the wires coming from my alternator.. like when someone changed it at some point they did a hack job with the wiring. what should the output be like 14.4? or something.. I honestly forget exactly what it's supposed to be..

You have checked the plug wells for oil, right?

It may also be that above 2600 rpm, voltage output from the alternator is [now] high enough to properly power the electrical system, or overcome the added resistance of a bad harness lead from the alternator.

Also I don't have cutout at high RPM as soon as I hit about 2600 rpm's I can floor it no problem but below that I can't give it more then an eigth of a pedal or else it feels like spark just is gone..

A harness-lead is that portion of the harness from the takeout off the main harness to the component/sensor - just like that section of harness for the alternator coming from the main front engine harness above the radiator.

You don't take the wire insulation off. If you suspect (or want to test for) a bad harness lead, you do what's called a wiggle test - basically you wiggle that section of the harness to simulate road vibrations/bumps in an effort to recreate a problem.

And when you say the TPS harness-lead do you mean all of the wires that go to it just make sure they are ok? I don't wanna take all the insulation off of the wires but I might just have to if I don't see any obvious wire damage on the outside.

Stop trying to do five-thousand things using a random shotgun approach. Focus on one component at a time until you can eliminate it as a possible source for the problem.

Get the alternator tested first (to include a diode test). Then check the alternator harness-lead. Then check the plug wells for oil. Then pull the codes, record whether they're KOEO, CM, or KOER codes. Then clear the codes and retest. Then drive the car, try to recreate the problem and again retest. If you [again] get a TPS code, clear the codes, do a wiggle test and retest the codes.

One thing/item/component at a time.

I'm picking up a coilpack tomorrow afternoon also so I'll try that out. I got tomorrow off so get the ideas flowin so I can try to get it running right! Thanks for the help I still have things to try if anyone has input please post

 

[IM Buddy8]

yes sir, thankyou for the help everything you explained is easy to understand and makes perfect sense. I'm going to start with that wire was soon as I take a shower. I checked the front plug wells for oil the first day I got it and the back ones yesturday. The front ones onlyl had a tiny tiny bit in like only one and the other two were dry. Buuuut.. the back ones had a decent amount of oil. I am going to replace the plus,wires, valve cover gaskets but if this oil in the back was causing the problem can I just dry it out in there clean off the oil on the wires and put them back on for now?

Car is a 95 MTX 151k miles

 

[yzstud]

yes sir, thankyou for the help everything you explained is easy to understand and makes perfect sense. I'm going to start with that wire was soon as I take a shower. I checked the front plug wells for oil the first day I got it and the back ones yesturday. The front ones onlyl had a tiny tiny bit in like only one and the other two were dry. Buuuut.. the back ones had a decent amount of oil. I am going to replace the plus,wires, valve cover gaskets but if this oil in the back was causing the problem can I just dry it out in there clean off the oil on the wires and put them back on for now?

Car is a 95 MTX 151k miles

you could, but it would only be a matter of time before the wells fill up with oil again. you need the valve cover gasket and spark plug well seals

buy em here: http://www.rockauto.com/catalog/x,carcode,1138957,parttype,5500

or here: http://rcmautomotive.com/id4.html

 

[IM Buddy8]

The coilpack looks new already..

I'm not sure exactly which wire to test and is a multimeter alright to test it with?

 

[IM Buddy8]

I was getting 14.86 from the output/positive on top of the alternator at idle is that too high?

 

[Storm-Chaser]

Anything above 14.5v suggests a fault/failure in the voltage regulator. Take the alternator off and have it tested at Advance Auto or O'Reilly's. Also, check the voltage output at the battery, as well as verify that the alternator is putting out 130A under a load.


It's not uncommon to find oil only in the rear plug wells - most people don't check the rear-wells, and most people trying to prep a car for sale on-the-cheap will skip the rear plug-wells as well and guide you to checking only the front plug-wells.

You can temporarily get by, by cleaning-out the oil in the plug wells (there's a number of "techniques"). It will eliminate the loss of power below 2600 rpm until the oil begins to accumulate again, but if you've fouled a plug it will not usually clear the miss.

 

[Storm-Chaser]

Oh, and that blue writing on the alternator, suggests that it is a junkyard-pull.

 

[IM Buddy8]

I'm gonna get the oil out completely today clean it up nice and if it helps i'll go buy valve cover gaskets (plug ones too) new wires and new plugs. And I'll have the alternator tested. I might leave this thread alone for a few days and I'll do some work and I'll post any progress when I can I gotta get to the bottom of this.. Thank you and any ideas you guys may have let me know

 

[yzstud]

did u try swapping out the coil pack yet?

 

[IM Buddy8]

no I didn't.. I guess I assumed mine looks brand new maybe I should still try it though.. But today I unplugged the MAF and drove it like that and I could give full throttle under 2k rpm's it ran like crap but it wasn't cutting out like before.. MAF sensor has been swapped with 2 cars so it isn't the original one I bought it with anymore so maybe it's the wring? Somewhere it is reading incorrect about how much air it's letting in. Possibly PCM? or wiring?

 

[Sho Amo]

ive never seen a black coil pack like that