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  #1  
Old 06-04-2011, 12:16 PM
Atheist Ford guy
 
Join Date: Aug 2010
Posts: 26
Default Surges/rough idle

My ranger has a surging at highway speeds....like it isn't getting enough fuel....or maybe too much? It also has a piss poor idle...

Parts replaced:

TPS
IACV
ECT
Plugs/wires
Fuel Filter
Ran seafoam through the fuel system (probably wan't a great idea as the truck ran better prior to doing this).

I am heading down to a buddies house tomorrow to run a fuel pressure test...any other ideas/stuff I should check into??
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1987 Ranger base model. 2.9v6 longbed 2wd A4LD Auto.

1995 Ford Bronco XLT, 6" Superlift, 35" Cepek M/T's, 351w/E4OD.

1995 Ford Escort LX Sport, 225k miles and still ticking away!
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  #2  
Old 06-04-2011, 12:49 PM
Muddy, as usual
 
Join Date: Oct 2009
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Default Re: Surges/rough idle

Double check plug gap. Also make sure you have good fuel pressure. Pull your air filter and see if it runs smoother without it, if it does, replace it.
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2003 EDGE front clip conversion
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1969 Mercury Cougar
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  #3  
Old 06-05-2011, 08:21 AM
Atheist Ford guy
 
Join Date: Aug 2010
Posts: 26
Default Re: Surges/rough idle

Checked the plug gap when I put the new ones in and the air filter is new though it is a garbage Fram filter. I think it is the high pressure pump.
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1987 Ranger base model. 2.9v6 longbed 2wd A4LD Auto.

1995 Ford Bronco XLT, 6" Superlift, 35" Cepek M/T's, 351w/E4OD.

1995 Ford Escort LX Sport, 225k miles and still ticking away!
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  #4  
Old 06-05-2011, 09:05 AM
Semper Paratus
 
Join Date: May 2009
Posts: 274
Default Re: Surges/rough idle

I had a 90 bronco II with 2.9 with the same problem. It would even throw a cel indicating a ignition problem and then a few miles later it would be fine. I replaced everything you have plus some, including new fuel pressure regulator, ignition module and checked for vacuum leaks. Ended up being the o2 sensor.
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Mods: Roush hood & cai, ASP pwr pulley, hot wtr bypass, 180 therm, e-fan, Gibson exh., 4.10 l/s, FabTech lift, kyb's, bii sway bar. 31x10.50 Yokahama ATs, Panther rims, light bar, SS grille, 03 stang buckets, explorer console, hurst shifter


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  #5  
Old 06-05-2011, 09:08 AM
I am THE Hank Hill.
 
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Default Re: Surges/rough idle

I'm gonna say either O2 or MAF. Most likely O2, though. IIRC, they are only about $40 for the 2nd gens, but I'm not positive on that.
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92 Ford Ranger Supercab XLT 4X4.
Not a ton done to it, but it's nowhere near finished
05 Chevy Silverado 1500 W/T 4X4
Way too much done to list and it's also not even close to done

"The only woman I'm pimping from now on is Sweet Lady Propane. And I'm tricking her out all over this town."
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  #6  
Old 06-05-2011, 12:53 PM
Psycho Pete
 
Join Date: Jun 2009
Posts: 1,487
Default Re: Surges/rough idle

He will have a map sensor, no MAF. Pull codes and go from there. No check engine light to let you know when the computer sees something out of range or a faulty circuit. Could be anything from a vacuum leak to a bad sensor. Problems in EFI systems can get complicated, that is why the self tests are there - to help you narrow down what it is.
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1987 Ford Ranger Short Bed 5.0L/T-5 Project
1988 Ford Ranger Long Bed Parts Truck
1993 Ford Tempo 2.3L OHV HSC Auto - D/D Stock.
1999 Honda Accord VTEC Auto
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  #7  
Old 06-05-2011, 04:36 PM
I am THE Hank Hill.
 
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Default Re: Surges/rough idle

Quote:
Originally Posted by Psychopete View Post
He will have a map sensor, no MAF. Pull codes and go from there. No check engine light to let you know when the computer sees something out of range or a faulty circuit. Could be anything from a vacuum leak to a bad sensor. Problems in EFI systems can get complicated, that is why the self tests are there - to help you narrow down what it is.
DOH! Didn't even look at the year, lol.
__________________
92 Ford Ranger Supercab XLT 4X4.
Not a ton done to it, but it's nowhere near finished
05 Chevy Silverado 1500 W/T 4X4
Way too much done to list and it's also not even close to done

"The only woman I'm pimping from now on is Sweet Lady Propane. And I'm tricking her out all over this town."
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  #8  
Old 06-05-2011, 08:32 PM
Atheist Ford guy
 
Join Date: Aug 2010
Posts: 26
Default Re: Surges/rough idle

Well it turned out to be a fouled plug. I am always good checking the gap....but somehow one slipped past. I felt stupid as hell....but whatever, the truck drives awesome now!
__________________
1987 Ranger base model. 2.9v6 longbed 2wd A4LD Auto.

1995 Ford Bronco XLT, 6" Superlift, 35" Cepek M/T's, 351w/E4OD.

1995 Ford Escort LX Sport, 225k miles and still ticking away!
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