Car runs like crap but has more HP?

[Jrad0425]

well... not exactly, it all started Sunday when my mint 84 944 (sport package.. lol) decided to die after pulling out of autozone.... I guess it knew better then to let me put anything from that place near her... so i pull out car dies down the road out of gas i presume... terrible idle, and gas is applied it fumbles and stalls.... come back with my flatbed (usually used for work not my car haha) try the car one more time and it runs?!? do a quick burnout and on the flatbed and home it goes, call my mechanic and he says maybe it was just crap in an injector run the car at 4k and let it blow anything out i do that and then a quick run to the gas station and i throw some fuel injector cleaner in the tank as well... I go to start it and what do you know it wont run... back to square one... so i take it to my mechanic yesterday and have them do a bunch of stuff.. recharge A/C, oil change and filter, fuel filter, check all my injectors check fuel pump and they discover a collapsed cat... this would explain most of my symptoms .. so i opt for a cat delete.. who need emissions anyway, i go to pick the car up and damn the same problem once again.. so it wasn't the cat that was the problem, or maybe a contributing factor? anyway i get some freed up HP now with out the bad cat in there but anyone have any idea what could be wrong? SYMPTOMS: runs excellent when cold or not at operating temp, once it reaches temp and i shut it down it will restart fine and idle terribly and not be drivable due to stumble and stall on any depression of the gas pedal... but if you leave the car until it is cold again it will run fine.... crazy stuff i guess... thanks everyone for the help..


damn that was long

[drew1]

There are two temp sensors on the motor. One that will work the guage & the other sends a signal to the computor. If this is bad it could make the car run rich when warm. By itself it would not give the extreme symptoms you have but combine it with something else like a bad fuel pressure regulator, it can.

[Jrad0425]

thanks for the tip.. ill let everyone know as soon as i get a positive fix from my p-car guy... but please keep the ideas rolling.... AND what else should i do to her to spunk her up a bit more im sure the cat delete will give her a little more spunk any other ideas?

[Makis]

The O2 sensor can cause problems too. The O2 is normally ignored when cold but when the engine is warm the ECU uses it to control fueling. If bad it will cause over fueling. Check if your problem is related to over fueling though. Bad gas smell and wet spark plugs is a symptom. Over fueling may be the reason the CAT died.

[hpservertech]

Simple problem. DME relay. Always, always carry a spare with you. Will do exactly what your describing.

[Gary2397]

Based on the symptons you described, you may have ignition and ground problems. Most of the time, if the coil gets hot , you'll have problem.

Is your mechanic a Porsche , or European specialist?
Bad throttle switch causes bad idle, accelerate problem.

[xero]

My turbo did the EXACT same thing once.
It's the "DME Temp sensor" like Drew1 said.

[CJFusco]

Just for the record, a cat delete on a NA car won't necessarily make your car faster. It will move the power band somewhat north, but might cost you some low-end torque. I remember the concept of back-pressure being discussed here pretty comprehesively a few years back, complete with physics problems and diagrams that I didn't understand.

Actually, there were members on both sides of the debate. Some said "no cat = more HP," some argued the opposite.

Of course, if your problem was a clogged cat, the car would certainly run better without it.

Originally Posted by Jrad0425

damn that was long

That's what she said?

[Cking1975]

The next deparment law enforcement is going to be adding is the "green police" and that will further be rushed when a democrate becomes president. I recommend following the law, not the horse power. If you had a ford, then you may get some extra HP, but cars like Porsche, Hondas, etc, very little can be gained...and we all know...ITS ABOUT THE BOOST !

[bud9344]

DME relay #993 615 227 00
Just replace mine(83 944 N/A Auto)! Drove about 20 mile and it dies, sometime it just stumble.
According to my supplier the DME relay get tired and Old LOL .Once it get hot it looses contact.
Peace

-------------------------------------
Bud

87 930 black
86 951 black
86 944 N/A red (parts car)
87 944 S white
83 944 N/A black
83 944 N/A white Auto
Only the Black & White still on the road

[bud9344]

DME relay #993 615 227 00
Just replace mine(83 944 N/A Auto)! Drove about 20 mile and it dies, sometime it just stumble.
According to my supplier the DME relay get tired and Old LOL .Once it get hot it looses contact.
Peace

-------------------------------------
Bud

87 930 black
86 951 black
86 944 N/A red (parts car)
87 944 S white
83 944 N/A black
83 944 N/A white Auto
Only the Black & White still on the road

[Slam]

You can reflow all the solder joints in the DME relay and maybe that'll get some more life out of it.

[Dantilla]

Has anyone seen a DME relay cause poor running?

In my experience, when the DME relay goes South, the car will not run at all. (Yes, I've got another one in the glove box).