Question for the Modders...

Sierra3

Registered
Here's a wierd problem that just surfaced. Let me start out with the engine mods and car. 95 mark 8 with FMSport 4:10's, Eaton posi w/stud kit,true dual exaust with Xover and magnaflows, Poly carrier bushings and ADDCO sway bar in rear,Intec chip,Cobra 130AMP alternator,two step colder plugs and motorsport wires,B&M tranny cooler,Dynotech driveshaft,225 LPH Walbro pump and 180 degree thermostat. New parts on engine include new fuel filter,EEC in car,TPS,IAC valve,EGR valve.

Thermostat isn't installed yet as i read that computer pulls timing and full throttle fuel curves before engine reaches "operating range" of 190 or so. Am reluctant to do thermostat change untill more research is done to find out if our cars do the same as mustangs with this issue on engine. Maybee it can be fixed with a simple reburn on EEC chip.

Here is the problem that surfaced directly after having 225LPH walbro fuel pump installed. Everything was running great and like a raped ape before i had fuel pump installed. I was pulling 9.002 in 1/8th and getting 21 MPG regular driving on highway running 75 or 80. Now my gas milage has INCREASED with the bigger pump. Car has a noticeable lower rummble of exaust tone too. Also i developed a faint "fishy smell" when exiting car. Perhaps I've toasted the original catalytics? I have yet to do the O2 sensors and will be going with 2 from BOSH this week. Hopefully I havent toasted the cats yet, but at 120,000 miles how long can they last? (I have the two original units left intact on car up front, going directly into a X-pipe then to true duals into magnaflows.)
This leads me to believe that the computer is Decreasing my injector pulses times or thinning out the fuel flow to compensate for the extra fuel? (which should still be the same after factory regulator)It should just be "more available on tap for the regulator", not an increase. I still have the original fuel presusure regulator from factory on car. I am planning on going with a unit from Aeromotive. Checks at the schrader valve tell me i have a solid 40psi at idle. I am running a stock MAF and box with no resonators and cold air comming through 3" pipe from front of grille into the airbox, ahead of K&N airfilter.I plan on getting a Lightning MAF from Dennis Reinhart soon.

The car used to have extremely crisp throttle response and threw you back into the seat downshifting at WOT. It now bogs and roars and still pulls like crazy, but nothing like before when floored. Is this a simple thing of "its dyno time" to get tuned and new "parameters" reburned into chip? or does it sound more involved. Sorry so long, but i wanted to nip questions on what i had in the bud and was wondering if anyone else had these problems in thier upgrade stages.
 
RE: Question for the Modders...

Also i developed a faint "fishy smell" when exiting car.

Ah, thought that was you Jeff!!!! Welcome aboard.......and that fishy smell wouldn't have anything to do with you living in Florida, would it?????

Did you notice these changes just after the pump install, or were they there before? Sounds like this is a question for Geno or Dennis. I'd be under the impression that if your converters were toast, it'd run worse. Wonder if only 1 is bad, giving you just a partial problem. So how do we check cats, anyway???

You could also ask Ponyfreak if he had to do any fine tuning after adding his hi-perf pump.

How 'bout it, gentlemen?
 
RE: Question for the Modders...

It could be any number of things.
It could be the O2s are going bad.The cats wouldn't smell fishy.More lick rotten egg sulfery kind of smell.If thats the smell you are getting then pull your exhaust out of the way and take a long pry bar and bang out the honeycomb material in the cats.Then replace your o2s.
 
RE: Question for the Modders...

i might just do the crowbar trick when i do the O2 sensors...was wondering if it would have any negative effects on sensors.? running empty cats? or dont the sensors care? thanks...ill check back here when i get off of work...before i go buy the o2 sensors.
 
RE: Question for the Modders...


If you have a Service Manual, (I have the CD version) under Group 09: Exhaust System, Section 09-00 Diagnosis and Testing there is a Pinpoint Test A: Restricted Exhaust System Test, A2: Vacuum Test. It explains how to test the exhaust with a Vacuum/Pressure Tester. You should have above 53.8 kPa (16in-Hg) at a intake manifold vacum source while engine running at 2000 rpm. If not then you need to begin checking as you disconnect sections of exhaust system to determine problem.
 
RE: Question for the Modders...

i might just do the crowbar trick when i do the O2 sensors...was wondering if it would have any negative effects on sensors.? running empty cats? or dont the sensors care? thanks...ill check back here when i get off of work...before i go buy the o2 sensors.

Yep, I bet the sensors care (as in constant check engine lite, not to mention what the computer may do to the fuel mixture???). Those of you who have experience with burning chips or having one burned, can this little problem (assuming there will be a problem) be programmed out????
 
RE: Question for the Modders...

yup i bought the CD a long while back when it was first offered to the board. However i like a big manual to flip through while in the garage..im dont yet have the luxury of the notebook computer. So for all my diagnostics i print out the schematic and pin tests and carry them into garage. then find sutible paper weights or the fan eats them..lol confetti is fun to pick up.
 
RE: Question for the Modders...

95. You should be okay. If there are another set of o2's after the cats, then you need to get the computer reflashed or o2 simulators. But i think that is just 97 up.
 
RE: Question for the Modders...

It wont affect the sensors.
What year car again?
Aha. Thanks for correcting me. I had a conversation with somebody about removing the cats, and as my memory resurfaces, the problem did deal with O2 sensors, but not affecting them. My bad.
 
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