Cold driveability problem...need help!

Tomzilla · 05-13-2003, 04:30 AM

Hi gang,
I'm trying to help a friend with his '93 Coupe. At first startup in the morning he says he feels a "miss" . I haven't experienced it myself but have driven the car after it had cooled for a few hours and it doesn't do it. According to him he has to feather the throttle initially to keep the car running until the temp comes up. After the temp gauge reads 180 it runs fine. My assumption is something is causing the ecu to lean out the fuel until the car goes into closed loop. He has recently replaced the o2 sensors with no effect. I replaced the IAC and EGR and am hoping this cures or at least diminshes the effect. After scanning for codes the only one that comes up is 33 which is egr..........
Any ideas are appreciated

Nixon1 · 05-13-2003, 01:11 PM

Did you reset the ECM after installation of any new sensors? Dunno about the Ford ECM system, but on the Chevy system, if you dont erase the ECM's memory after replacing a sensor, the car acts REALLY strange and throws check engine codes that make no sense because it's already "learned" to operate with a faulty sensor. I've got a miss at idle too on mine...and if I toe the throttle really quick it misfires pretty bad. I attribute mine to bad valves on one cylinder though (at least that's my THEORY)

Tomzilla · 05-13-2003, 02:05 PM

Yes, we reset the codes with our scanner as well as the old battery disconnect trick. But the code(33) keeps coming back.

Coupe50h · 05-15-2003, 08:31 PM

yea my car has a 180 too, im not sure why, but in the morning it kinda runs rough, wants to die, gives a sputter going up a hill, but once it's at temperature, it runs great, i cant figure it out, i run codes but get air thrmactor codes sinced i removed all of it.
hope you figure it out.

Tomzilla · 05-16-2003, 01:29 AM

That's pretty much the same experience were having. Oh well, I replaced the IAC and EGR and gave the car back to the owner to see if the problem still exists. Haven't heard back yet but I have some other ideas I need to test out.
Thanks again

LX5liter · 05-17-2003, 11:28 AM

It sounds like you have the problem licked with the EGR replacement, but if the problem persists, it could also be the engine coolant temperature sensor (ect).

05-13-2003, 04:30 AM	#1
Tomzilla Registered Member Join Date: Dec 1999 Location: Large cardboard box under a bridge, Hi Posts: 21	Cold driveability problem...need help! Hi gang, I'm trying to help a friend with his '93 Coupe. At first startup in the morning he says he feels a "miss" . I haven't experienced it myself but have driven the car after it had cooled for a few hours and it doesn't do it. According to him he has to feather the throttle initially to keep the car running until the temp comes up. After the temp gauge reads 180 it runs fine. My assumption is something is causing the ecu to lean out the fuel until the car goes into closed loop. He has recently replaced the o2 sensors with no effect. I replaced the IAC and EGR and am hoping this cures or at least diminshes the effect. After scanning for codes the only one that comes up is 33 which is egr.......... Any ideas are appreciated __________________ 1990 ex-chp Coupe. Mildly ported Twisted wedges, custom cam,Holley SysteMax intake, 1 5/8" longtubes, Mac prochamber, Flows,Tremec 3550, 4.30's,Griggs subframes, C&L 76mm, 30# injectors,70mm t-body etc. Best e.t. [b]11.94 @ 113.03 mph with 1.488 60ft

05-13-2003, 01:11 PM	#2
Nixon1 Registered Member Join Date: Jan 2003 Location: Palm Bay, FL Posts: 432	Did you reset the ECM after installation of any new sensors? Dunno about the Ford ECM system, but on the Chevy system, if you dont erase the ECM's memory after replacing a sensor, the car acts REALLY strange and throws check engine codes that make no sense because it's already "learned" to operate with a faulty sensor. I've got a miss at idle too on mine...and if I toe the throttle really quick it misfires pretty bad. I attribute mine to bad valves on one cylinder though (at least that's my THEORY) __________________ '91 Mustang GT 5.0 AOD Daily Driver Current stats: NEW 302 short block, E-303 cam (@.050, 220/220, .498/.498, 110 degrees), 1.6 roller rockers, Performer RPM heads (aluminum, 1.9/1.6, 60cc chambers), Cobra intake, Granatelli 75mm MAF, Billet AFPR, Equal-Length Shorty Headers, Off-Road X Pipe, Flowmasters, 4.10 POSI 13.73 at 103.8, ~2.2 60'

05-13-2003, 02:05 PM	#3
Tomzilla Registered Member Join Date: Dec 1999 Location: Large cardboard box under a bridge, Hi Posts: 21	Yes, we reset the codes with our scanner as well as the old battery disconnect trick. But the code(33) keeps coming back. __________________ 1990 ex-chp Coupe. Mildly ported Twisted wedges, custom cam,Holley SysteMax intake, 1 5/8" longtubes, Mac prochamber, Flows,Tremec 3550, 4.30's,Griggs subframes, C&L 76mm, 30# injectors,70mm t-body etc. Best e.t. [b]11.94 @ 113.03 mph with 1.488 60ft

05-15-2003, 08:31 PM	#4
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	yea my car has a 180 too, im not sure why, but in the morning it kinda runs rough, wants to die, gives a sputter going up a hill, but once it's at temperature, it runs great, i cant figure it out, i run codes but get air thrmactor codes sinced i removed all of it. hope you figure it out. __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

05-16-2003, 01:29 AM	#5
Tomzilla Registered Member Join Date: Dec 1999 Location: Large cardboard box under a bridge, Hi Posts: 21	That's pretty much the same experience were having. Oh well, I replaced the IAC and EGR and gave the car back to the owner to see if the problem still exists. Haven't heard back yet but I have some other ideas I need to test out. Thanks again __________________ 1990 ex-chp Coupe. Mildly ported Twisted wedges, custom cam,Holley SysteMax intake, 1 5/8" longtubes, Mac prochamber, Flows,Tremec 3550, 4.30's,Griggs subframes, C&L 76mm, 30# injectors,70mm t-body etc. Best e.t. [b]11.94 @ 113.03 mph with 1.488 60ft

05-17-2003, 11:28 AM	#6
LX5liter dude5l Join Date: May 2001 Location: Grande Prairie, Alberta, Canada Posts: 603	It sounds like you have the problem licked with the EGR replacement, but if the problem persists, it could also be the engine coolant temperature sensor (ect). __________________ Good luck! Brad R. 1992 L.X. 5.0 coupe MODS: A few little bolt ons New Best time ...11.60 @ 128 mph @ 2000+ ft altitude. Rice Haters Club member #39 Users rides #2542

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