Why does it do this?

DemonGT · 04-27-2002, 01:17 AM

When I start my car, sometimes it starts, then the rpm drops really low almost killing the engine, then shoots up to about a grand, then gradually settles. A lot of ppl say its because it's cold but it seems like it drops way too much.

Also: The other day I was pulling into work; I had the clutch pushed in and my engine suddenly reved to about 1200 then went way down, then reved again, then died. I was driving it tonight, going around a corner and had the clutch in and it started running really low and rough - but didn't die. Any ideas on what it could be? Both times I was turning. Hummm?

sn95gt19 · 04-27-2002, 02:54 AM

i have the same prob. with my 95 ever since i put the e303 cam in it, it does the same thing

fubar89lx · 04-27-2002, 08:17 PM

I had the same problem. I put an IAB plate from Ford on mine and bumped the idle up a bit and it stopped. I also put a new IAB valve on. You can pick up the plate at ford dealer. It was a tsb for Fox back in the day. Hope this helps.

Coupe5oh · 04-27-2002, 11:15 PM

My car does that too, especially when it's hot, it will start then idle low, then the computer responds and kicks it up, read my old post about "my car sounds like it has an e-cam", someone said it could be a broken valvspring, but not likely, my car has lost some upper rpm pull lately, but im still running 13.9's on street tires, i dont know? what is your thermostat temp?

Pongo · 04-28-2002, 12:54 AM

You might check your O2 sensors. They could be bad or one may not be pluged in. I duno just a thought.

Steve

Bad89stang · 04-28-2002, 01:32 AM

Check your TPS voltage and make sure that it is clean. This may not fix it, but it would eliminate that area.

Stang Runner · 04-28-2002, 07:17 AM

I had Something very close to that was A Bad O2 om my At lest Clean them and look at them.

Bad89stang · 04-28-2002, 03:26 PM

What do you clean O2 sensors with that doen't ruin them?

Coupe5oh · 04-28-2002, 04:24 PM

I cleaned my o2's with wd=40, i had to replace one, but now that you bring this up, my h-pipe doesnt allow one of my 02's to screww all the way in, something i will look into....thanks

Pongo · 04-28-2002, 08:05 PM

OK - Dont try this without learning how first! It goes something like this though: 1. Remove O2 sensors(careful they can break off in the pipe) 2. put them in a vice and heat them up with a torch. 3. use a wire brush (drill mounted) and make em shine. Put em back and they may work now.

I realy would not use any kind of oil on the O2 sensors. Oil is why they need cleaned in the first place. I know some solvents can mess them up. All you want is clean bare metal on the O2 sensor.

Steve

04-27-2002, 01:17 AM	#1
DemonGT Registered Member Join Date: Aug 2000 Location: Wisconsin Posts: 879	Why does it do this? When I start my car, sometimes it starts, then the rpm drops really low almost killing the engine, then shoots up to about a grand, then gradually settles. A lot of ppl say its because it's cold but it seems like it drops way too much. Also: The other day I was pulling into work; I had the clutch pushed in and my engine suddenly reved to about 1200 then went way down, then reved again, then died. I was driving it tonight, going around a corner and had the clutch in and it started running really low and rough - but didn't die. Any ideas on what it could be? Both times I was turning. Hummm? __________________ '91 GT,410W,10.5 to 1 comp,Victor Jr. heads,Victor 5.8 intake,FTI cam,Crane retro fit lifters,Scorpian 1.6 RR's,Melling HV oil pump,MSD distro.,Canton oil pan,FMS flywheel,Romac balancer,FMS timing chain,Accufab 90mm TB,C&L 76mm maf, 42lbers,HD clutch,K&N air filter,Mac long tubes,Pro dumps,powerchamber,FMS 9mm wires,180 thermostat,Ford Racing gauges,5inch Tach,centerline convo pro's,nitto DR's,Pro3i lower control arms,50/50 shocks,3.55 gears,TFS HD diff. cover Next year: Tremec TKO,Spec stage 3 clutch,alum driveshaft,complete fuel system www.angelfire.com/linux/demondan

04-27-2002, 08:17 PM	#3
fubar89lx Registered Member Join Date: Apr 2002 Location: Palm Bay,FL Posts: 24	I had the same problem. I put an IAB plate from Ford on mine and bumped the idle up a bit and it stopped. I also put a new IAB valve on. You can pick up the plate at ford dealer. It was a tsb for Fox back in the day. Hope this helps. __________________ Best E/T-13.2 Best MPH-108 Mods-Full exhaust,U/D pulleys,73mm mass air,70 mm M/A,Cobra intake,Crane 1.7 R/R,E303 Cam,3.55 gear,125HP Nitrous Works.

04-27-2002, 11:15 PM	#4
Coupe5oh Registered Member Join Date: Nov 2001 Location: SanAntonio, Tx Posts: 734	My car does that too, especially when it's hot, it will start then idle low, then the computer responds and kicks it up, read my old post about "my car sounds like it has an e-cam", someone said it could be a broken valvspring, but not likely, my car has lost some upper rpm pull lately, but im still running 13.9's on street tires, i dont know? what is your thermostat temp? __________________ Police package 5spd 90 Lx, Stock original motor, 3.27grs, BM fan, fms 10.5 clutch, D&D quadrant, and adjuster, ADS chip, 180 stat, mac cai, mac h-pipe, mac subframe connectors, ASP crank pulley, ripper shifter, 26x10.5 M/T sport pros welds. 246 hp according to analyzer Race weight: 3,120 E.t-13.57 with 26x10.50's e.t. streets. 1.88 60' mph- 99.92 mph

04-28-2002, 01:32 AM	#6
Bad89stang Registered Member Join Date: Aug 2001 Location: Ft. Worth, TX Posts: 456	Check your TPS voltage and make sure that it is clean. This may not fix it, but it would eliminate that area. __________________ You're gonna need your seatbelt

04-28-2002, 07:17 AM	#7
Stang Runner Registered Member Join Date: Jun 1999 Location: Walker, MI, USA Posts: 1,202	I had Something very close to that was A Bad O2 om my At lest Clean them and look at them. __________________ Engine: steel mounts, Under drive pulleys, K&N, GT-40 Intake ported Lower, No power steering, No A/C, Mac cold intake, 65MM TB, 255 Fuel pump, 24's, AFR 165 58cc, Rocker Arms 1.7with the stock Cam, 1 5/8 short headers, offRoad X-pipe Drive Train: 3.55, T-5 with a Pro 5.0 shifter 12.656@107.71MPH See It at www.T-racing.com/mustang.htm

04-27-2002, 02:54 AM	#2
sn95gt19 motors done......woohooo Join Date: Mar 2002 Posts: 799	i have the same prob. with my 95 ever since i put the e303 cam in it, it does the same thing

04-28-2002, 12:54 AM	#5
Pongo Registered Member Join Date: Apr 2002 Location: Springfield, Mo Posts: 18	You might check your O2 sensors. They could be bad or one may not be pluged in. I duno just a thought. Steve

04-28-2002, 03:26 PM	#8
Bad89stang Registered Member Join Date: Aug 2001 Location: Ft. Worth, TX Posts: 456	What do you clean O2 sensors with that doen't ruin them? __________________ You're gonna need your seatbelt

04-28-2002, 04:24 PM	#9
Coupe5oh Registered Member Join Date: Nov 2001 Location: SanAntonio, Tx Posts: 734	I cleaned my o2's with wd=40, i had to replace one, but now that you bring this up, my h-pipe doesnt allow one of my 02's to screww all the way in, something i will look into....thanks __________________ Police package 5spd 90 Lx, Stock original motor, 3.27grs, BM fan, fms 10.5 clutch, D&D quadrant, and adjuster, ADS chip, 180 stat, mac cai, mac h-pipe, mac subframe connectors, ASP crank pulley, ripper shifter, 26x10.5 M/T sport pros welds. 246 hp according to analyzer Race weight: 3,120 E.t-13.57 with 26x10.50's e.t. streets. 1.88 60' mph- 99.92 mph

04-28-2002, 08:05 PM	#10
Pongo Registered Member Join Date: Apr 2002 Location: Springfield, Mo Posts: 18	OK - Dont try this without learning how first! It goes something like this though: 1. Remove O2 sensors(careful they can break off in the pipe) 2. put them in a vice and heat them up with a torch. 3. use a wire brush (drill mounted) and make em shine. Put em back and they may work now. I realy would not use any kind of oil on the O2 sensors. Oil is why they need cleaned in the first place. I know some solvents can mess them up. All you want is clean bare metal on the O2 sensor. Steve