Skip to main content ↑ ↓
Topic: rogh idle.....lack of power...then good... (Read 13269 times) previous topic - next topic

rogh idle.....lack of power...then good...

The car has been great with the new engine, BUT, having one last issue to deal with. When I'm driving the car, I can feel a mild "pulsing" in the car. Like a very light surge (?). Hard to explain. Still runds great. Also, at randome times, the car starts to stumble with a rough idle, lack of power, and I turn it off and immediately turn it back on, then it's great. It did this with the last engine, through the A9P and X3Z ECM, with the aftermarket and Cobra MAF, I replaced the coil with an NOS piece, and the TFI with an NOS piece and even replaced the fuel pump. What else could cause it? Ignition switch or distributor, maybe?

I'll run codes again hopefully this evening.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

rogh idle.....lack of power...then good...

Reply #1 –
My 86 does this on a warm start up. Ill fire it up, it will run rough, occasionally rev up to about 2000Ron's then sputter. Sometimes it will die, especially when i hit reverse or try to crank the wheel. What's funny, if i can keep it running for a minute, then it won't do it at all again until o cycle the key off.

I haven't looked into it too much. I pretty much always drive a minimum of 25 miles each way. Only time its really a hassle is on a warm start up, or like if i shut the car off in a drive thru. Haven't even bothered to run codes yet.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

rogh idle.....lack of power...then good...

Reply #2 –
Mine doesn't have the high rev issues. It also doesn't happen upon startup. Usually after I get going. maybe three minutes into it, maybe not at all.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

rogh idle.....lack of power...then good...

Reply #3 –
I'm going to swap the distributor as soon as I can and go from there.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

rogh idle.....lack of power...then good...

Reply #4 –
I would definitely start with the distributor then are you still running an MSD box?
1983 Tbird with '03 Split Port V6 motor swap done! Headers, dual exhaust, 500CFM Edelbrock, 3G upgrade, Electric fan. 3.73 Gears and an FRPP Limited Slip. Five lug complete! 5-Speed conversion complete! Standalone Fuel Injection in progress...

rogh idle.....lack of power...then good...

Reply #5 –
I never had an MSD box.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

rogh idle.....lack of power...then good...

Reply #6 –
Oops. I mistook the model of the ECU for the model of an MSD box.
1983 Tbird with '03 Split Port V6 motor swap done! Headers, dual exhaust, 500CFM Edelbrock, 3G upgrade, Electric fan. 3.73 Gears and an FRPP Limited Slip. Five lug complete! 5-Speed conversion complete! Standalone Fuel Injection in progress...

rogh idle.....lack of power...then good...

Reply #7 –
I'm installing a Motorcraft ignition switch, and then probably a new distributor.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

rogh idle.....lack of power...then good...

Reply #8 –
My worthless two cents..
First check to see that all basic settings are correct, and no vacuum leaks, etc. That said, I have experienced your same exact symptoms, and the fix was: ICV (idle control valve), and 02 sensors are most likely your culprits.

rogh idle.....lack of power...then good...

Reply #9 –
Codes. Yawn....
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

rogh idle.....lack of power...then good...

Reply #10 –
Quote from: Haystack;447964
Codes. Yawn....

Make sure you HEGO sensors are reading the right banks.
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

rogh idle.....lack of power...then good...

Reply #11 –
I have a set of new O2 sensors. Haven't been able to do anything or run codes.. Flooding and heavy rains all over. I will as soon as i can.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

rogh idle.....lack of power...then good...

Reply #12 –
It was like that here the last couple of weeks. We had several straight days of rain, and rain every day for two weeks. Doesn't happen much in the dessert.

Let us know when you can get around to it.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

rogh idle.....lack of power...then good...

Reply #13 –
Quote from: vinnietbird;447982
I have a set of new O2 sensors.

Doesn't matter how old or new they are.  If the wires to the harness are reading the opposite sensor it can cause a situation just like you describe.  Been there, done that, and can verify that in fact it will not necessarily give a code cause I had none....

Run codes, but check the wie colors for your respective harness as well if nothing glaring pops up.
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

rogh idle.....lack of power...then good...

Reply #14 –
The wires should be good, but I will check it out. I was actually looking for an O2 harness the other day in the classifieds.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..