Rough idle since mods

Mustang_289 · 06-10-2004, 02:38 PM

Just recently put on the following mods: AFR165 heads, Typhoon Intake u/l, B303 CAM, 24LB injectors, C&L119A MAF in our 88GT that's been converted to MAF.

Everything is installed, timing set to 10 degrees, idle is really rough, fuel pressure is set around 40. Idle was fine before the above mods, any ideas on what else to check to get car to idle right?

Capri306 · 06-10-2004, 04:34 PM

Um, did you actually check the cam timing, or did you just get a new timing set and assume that it's right? Also keep in mind that it is a B303, so it's not going to have a smooth idle no matter what you do.

Other than that I'd check TPS voltage and make sure all plugs are firing. No check engine light?

Mustang_289 · 06-11-2004, 08:59 AM

Yes - we indexed the cam to zero. I feel real confident this was done right as we had a friend come in and do this for us.

tireburner163 · 06-11-2004, 02:47 PM

It's called a cam.

Mustang_289 · 06-11-2004, 04:31 PM

What ?????

Rev · 06-11-2004, 06:31 PM

I think Capri 306 is talking about "degreeing the cam" to see if all the specs are correct. Wondering if Tireburner is sniffing "brake cleaner" again, LOL.

Rev

~The Jester~ · 06-12-2004, 06:20 AM

I think Tireburner was referring to the fact that the B303 cam isn't gonna "idle" no matter what you do. I'd check all the above mentioned stuff, scan the computer for history codes, and lastly check and see if you maybe don't have an intake and/or vacuum leak somewhere.

tireburner163 · 06-12-2004, 11:08 AM

Quote:

Originally posted by ~The Jester~
I think Tireburner was referring to the fact that the B303 cam isn't gonna "idle" no matter what you do. I'd check all the above mentioned stuff, scan the computer for history codes, and lastly check and see if you maybe don't have an intake and/or vacuum leak somewhere.

There we go.

THe B-303 is a pretty lumpy cam is NEVER gonna idle smooth. It's gonna lope. Get used to it..........besides, it sounds so cool

-Josh, aka the tireburner

Hethj7 · 06-12-2004, 08:23 PM

Is the idle just loping a bit, or does it actually surge up and down? I am just wondering exactly what you mean by saying the idle is not smooth. I run the B-cam also and still fight off and on idle problems with it.

Just off the top of my head, make sure your TPS voltage is correct and make sure your IAB valve is clean.

Mustang_289 · 06-16-2004, 09:26 PM

im sorry guys the cam my son installed was actually the E-cam. the bad idle is not the cam(lets say my x-cam had a better idle than this does) i dont think the idling problem is due to the cam. the car wont even idle most of the time it just dies. black smnoke is pouring out of the back. my son checked for vaccuum leaks, checked fuel pressure, checked the wires to make sure they were on right, checked the timing. we dont know what else to check.

Hozer 88GTConv · 06-17-2004, 10:28 AM

Black smoke is fuel...

The usual suspects for poor idle:

vacuum leak
timing
tps voltage
bad iac

btw, I have a b-cam and it lopes but idles at 750 and doesn't budge.

I have 24 lbs too and 40 psi is too much I think, you should be around 38 psi tops.

good luck...

Dog5ohfun · 06-24-2004, 09:30 PM

Okay just thought I would add my two cents to this thread. I had the E cam and once I got it to idle it was awesome. Make sure you check the TPS voltage, .98 or .99 volts at throttle stop and no more than 4.5 volts and wide open throttle, DO THIS WITH THE CAR OFF AND KEY ON. Also go to a parts store and get a can of intake spray cleaner. It will help to clean out the IAC (Idle air control) valve. Lastly get the IAC adapter plate that will go between the IAC and its mount it has 2 adjustment screws on it so you can set your idle without messing with the throttle stop and the TPS. Once I did the above the car idled fine with an occasional hiccup. But, lastly what everyone else said is welcome to having a cam. The E cam will idle rough

88workcar · 06-27-2004, 08:44 PM

Go up on the timing and down on the fuel press. My B and E idled smooth, With SPEED DENSITY.

tmoss · 06-28-2004, 07:14 AM

I'd bet this is MAF related. Is the MAF calibrated for the injector size being used? Does the air filter get fan wash from the coling fan? If so, build a shield to keep the fan from blowing on the filter. Cleaned the MAF wires lately?

Capri306 · 06-28-2004, 09:54 PM

Another thought: MAF could be fixed high due to internal failure. Check MAF output voltage (at harness connector AND EEC-IV computer) and report back plz.

06-10-2004, 02:38 PM	#1
Mustang_289 Registered Member Join Date: Sep 2001 Posts: 512	Rough idle since mods Just recently put on the following mods: AFR165 heads, Typhoon Intake u/l, B303 CAM, 24LB injectors, C&L119A MAF in our 88GT that's been converted to MAF. Everything is installed, timing set to 10 degrees, idle is really rough, fuel pressure is set around 40. Idle was fine before the above mods, any ideas on what else to check to get car to idle right?

06-10-2004, 04:34 PM	#2
Capri306 Moderator Join Date: Sep 1998 Location: Grand Rapids, Michigan, USA Posts: 1,001	Um, did you actually check the cam timing, or did you just get a new timing set and assume that it's right? Also keep in mind that it is a B303, so it's not going to have a smooth idle no matter what you do. Other than that I'd check TPS voltage and make sure all plugs are firing. No check engine light? __________________ Capri306, Moderator The Mustang Works Online 1979 Mercury Capri 1987 5.0L Mustang LX Notchback 1993 5.8L Eddie Bauer Bronco

06-11-2004, 02:47 PM	#4
tireburner163 It's a lot like a race car Join Date: Aug 2000 Location: Meridian, MS Posts: 4,130	It's called a cam. __________________ 1987 Buick T-type 1998 HD Electra Elide

06-11-2004, 06:31 PM	#6
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	Degreeing the cam? I think Capri 306 is talking about "degreeing the cam" to see if all the specs are correct. Wondering if Tireburner is sniffing "brake cleaner" again, LOL. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe

06-12-2004, 06:20 AM	#7
~The Jester~ Rat Killer Join Date: Aug 2002 Location: Cold ass Ohio Posts: 1,143	I think Tireburner was referring to the fact that the B303 cam isn't gonna "idle" no matter what you do. I'd check all the above mentioned stuff, scan the computer for history codes, and lastly check and see if you maybe don't have an intake and/or vacuum leak somewhere. __________________ d-Con Racing "Nothing fancy, just 347 inches of RAT POISON!" MICE need not apply.....

06-11-2004, 08:59 AM	#3
Mustang_289 Registered Member Join Date: Sep 2001 Posts: 512	Yes - we indexed the cam to zero. I feel real confident this was done right as we had a friend come in and do this for us.

06-11-2004, 04:31 PM	#5
Mustang_289 Registered Member Join Date: Sep 2001 Posts: 512	What ?????

06-12-2004, 08:23 PM	#9
Hethj7 Mizzou Tigers Join Date: Apr 1999 Location: weston, MO United States Posts: 1,455	Is the idle just loping a bit, or does it actually surge up and down? I am just wondering exactly what you mean by saying the idle is not smooth. I run the B-cam also and still fight off and on idle problems with it. Just off the top of my head, make sure your TPS voltage is correct and make sure your IAB valve is clean. __________________ 2006 Mustang GT 1990 LX GT-40 motor 262 horsepower, 307ft-lbs (sold but forever loved) 1998 Contour SVT Rice Haters Club Member #244

06-16-2004, 09:26 PM	#10
Mustang_289 Registered Member Join Date: Sep 2001 Posts: 512	reply im sorry guys the cam my son installed was actually the E-cam. the bad idle is not the cam(lets say my x-cam had a better idle than this does) i dont think the idling problem is due to the cam. the car wont even idle most of the time it just dies. black smnoke is pouring out of the back. my son checked for vaccuum leaks, checked fuel pressure, checked the wires to make sure they were on right, checked the timing. we dont know what else to check.

06-17-2004, 10:28 AM	#11
Hozer 88GTConv Registered Member Join Date: Feb 2002 Location: Jacksonville, FL Posts: 706	fuel... Black smoke is fuel... The usual suspects for poor idle: vacuum leak timing tps voltage bad iac btw, I have a b-cam and it lopes but idles at 750 and doesn't budge. I have 24 lbs too and 40 psi is too much I think, you should be around 38 psi tops. good luck... __________________ 1988 GT Convertible 331 10:1 TW heads, GT-40 intake, MSD, TRW flattops, B Cam w/ 1.7's, MAC exhaust, 24's, 70 TB, 76 MAF, 3.73's, Pro 5.0, Koni's, Anderson PMS, Wideband 02, yatta, yatta... One week with new motor, two speeding tickets...joy

06-24-2004, 09:30 PM	#12
Dog5ohfun Registered Member Join Date: Feb 2002 Location: Arlington, Washington Posts: 92	Okay just thought I would add my two cents to this thread. I had the E cam and once I got it to idle it was awesome. Make sure you check the TPS voltage, .98 or .99 volts at throttle stop and no more than 4.5 volts and wide open throttle, DO THIS WITH THE CAR OFF AND KEY ON. Also go to a parts store and get a can of intake spray cleaner. It will help to clean out the IAC (Idle air control) valve. Lastly get the IAC adapter plate that will go between the IAC and its mount it has 2 adjustment screws on it so you can set your idle without messing with the throttle stop and the TPS. Once I did the above the car idled fine with an occasional hiccup. But, lastly what everyone else said is welcome to having a cam. The E cam will idle rough __________________ Black 1990 LX DSS Racing Super Pro Bullit 331, AFR 185, Anderson B31 Cam, 1.6 DSS rockers, Cobra Intake w/ 2 phenolic spacer, Aluminum DS, 3.73 gears, Tremec 3550, Lakewood SFI Bellhousing, MSD Digital 6+, Spintech Side Exhaust,

06-27-2004, 08:44 PM	#13
88workcar Registered Member Join Date: Oct 1999 Location: Pierre Part, La. U.S.A. Posts: 1,850	Go up on the timing and down on the fuel press. My B and E idled smooth, With SPEED DENSITY. __________________ 88workcar 1988 Mustang LX 342. 417rwhp @ 6800. 28 X 10 ET Drag, 4.30s, 10.69 @ 126.43 1.42 60ft. 11.13 @ 127.7 on BFGs 1.72 60ft Rice Hater # 42 To be old and wise, You must first be young and stupid I'm somewhere in tthe middle.

06-28-2004, 07:14 AM	#14
tmoss Registered Member Join Date: Mar 2003 Location: Saint Louis, MO Posts: 634	I'd bet this is MAF related. Is the MAF calibrated for the injector size being used? Does the air filter get fan wash from the coling fan? If so, build a shield to keep the fan from blowing on the filter. Cleaned the MAF wires lately? __________________ Tom (Torque) Moss 88Gt 5spd Vert, FLowmaster Catbacks, stock cam advanced 4° @ 108.5° ICL, NMRA prepped GT40P heads 1.85/1.55 valves and 1.7 rockers, MAC P headers Jet-Hot coated, 97 Exlporer intake (ported lower), TB and injectors. 277RWHP/330RWTQ (SAE). http://www.fastlanecars.com/

06-28-2004, 09:54 PM	#15
Capri306 Moderator Join Date: Sep 1998 Location: Grand Rapids, Michigan, USA Posts: 1,001	Another thought: MAF could be fixed high due to internal failure. Check MAF output voltage (at harness connector AND EEC-IV computer) and report back plz. __________________ Capri306, Moderator The Mustang Works Online 1979 Mercury Capri 1987 5.0L Mustang LX Notchback 1993 5.8L Eddie Bauer Bronco

Thread Tools
Show Printable Version Email this Page
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Rough Idle	lovinspeed01	Windsor Power	13	04-29-2003 11:40 AM
Rough Idle??	ImportKiller	Windsor Power	1	01-17-2003 02:38 PM
help rough idle, missing	speed demon	Small Ponies	6	12-03-2002 12:55 PM
rough idle	logan	Windsor Power	1	08-09-2002 08:13 PM
Rough Idle	Joeys86Stang	Windsor Power	2	11-08-2001 10:58 PM