Engine problem

[zombiehouse]

If I am at cruising speed, where I am not adding to the gas, the car runs fine. It idles fine too. As soon as I give it some more pedal then the sputtering starts. Once I stop accelerating and just cruise along it is fine. When I slow down to go around a corner at an intersection and give it gas again the sputtering is bad. It embarrassing to hear the sound it makes. If I try to pull away on the freeway it is almost as bad. I have an Airaid CAI. I also have a Magnaflow dual exhaust. Those are the only 2 mods I have done. Well, I changed the fuel filter and the problem continues. Any ideas?

[Juturnax65]

what about the spark plus? spark plug wires

what kind of car is it?

[BondoSHO]

Tried swapping out the CAI for stock, or just cleaning the MAF? Could also be a fuel filter issue.

[Nicksbluestang]

Tried swapping out the CAI for stock, or just cleaning the MAF? Could also be a fuel filter issue.

dawt.....

[Martini]

well you need spark, fuel, and compression.
you spark is fine cause if not you would suffer at low speed (cruising speed).
you got compression because the same is happening.
so it has to be in your air/fuel mixture.

you changed the filter.
check the fuel pump. if thats good
check your throttle body make sure that the fuggin butterly valvle isn't sticking.
if those two are fine only other thing i can think of is your injectors.

[black3v4.6]

well you need spark, fuel, and compression.
you spark is fine cause if not you would suffer at low speed (cruising speed).
you got compression because the same is happening.
so it has to be in your air/fuel mixture.

you changed the filter.
check the fuel pump. if thats good
check your throttle body make sure that the fuggin butterly valvle isn't sticking.
if those two are fine only other thing i can think of is your injectors.

I disagree, I would check the electronics first. Pull out the plugs and see if they are firing and also look at the condition. It will tell you if you are running lean or rich by the color. If its running lean/rich then I would look into the air/fuel mixture.

[Martini]

since by experience now (:mad:) i know that plugs and wires dont go bad quickly. i dont see why you would need that.

pulling the plugs to see if youre lean/rich then go back and fix the fuel pump/throttle body.

i'm just saying from personal experience of plugs and wires dont go bad often.

[zombiehouse]

Another symptom I just noticed. I only get the problem when the car is warmed up. This is getting more confusing. I am not getting a CEL. I changed the fuel filter yesterday with no luck. If the throttle body was sticking I would think I would have the problem all of the time. I am going to try swapping the stock airbox back in later this afternoon. How do I clean the MAF?

[black3v4.6]

since by experience now (:mad:) i know that plugs and wires dont go bad quickly. i dont see why you would need that.

pulling the plugs to see if youre lean/rich then go back and fix the fuel pump/throttle body.

i'm just saying from personal experience of plugs and wires dont go bad often.

your experience plugs and wires don't go bad often? How many years of experience do you have working as a certified mechanic?

Your manual will tell you right off the bat that plugs and wires go bad more often then a fuel pump/throttle body/injector. Just look at the intervals of when you have to replace each part and it will tell you how often they go bad. Pretty sure your manual suggests that you change your spark plugs and wires more often then a fuel pump, throttle body, or injectors.

And notice I didn't say to just go out and replace them but to check them. Checking the plugs is going to tell you about the fuel system. It will tell you exactly which cylinder banks are doing what so you can narrow down the problem if the igintion system is good. This is steps a mechanic would take to narrow down the problem, not just say, spark plugs and wires don't go bad so rule them out and look at fuel.

[Nicksbluestang]

are any of you guys actually ASE certified to be giving out info like that?
:look:

To the o/p do what sean(bondosho) said in his post

[vtecftw]

last time i tried washing my engine and ended up filling the plug holes with water. had the same problem. light throttle drove fine, any more throttle would misfire like crazy. sprayed it out with an air compressor and worked fine after that. it IS possible it could be the plugs/wires.

[black3v4.6]

I just worked on a customers car last week where he had the same symptons. The problem was one bad spark plug. The electrode wore down prematurely. All the plugs were correctly gapped at .045 and that was .060. He had less than 20,000 miles on the plugs. Changed the plugs and the car ran good as new. So I would like to know where you get your info that plugs just don't go bad. It was also the first thing I checked and fixed the car in less than 30 min.

[zombiehouse]

Thanks for the replies. I am going to swap the stock airbox back in. Then I am going to run over and get new plugs. I have heard I should get the Autolite copper plugs. Are these what you would recommend? Does anyone have the number for the plugs I would need?

[vtecftw]

http://forums.modulardepot.com/showthread.php?t=2218

This list was originally started by ALLMTR2V on the corral and alot of people helped to get it right. I thought it would be a good addition to the MD!

MOTORCRAFT

PART# / HEAT RANGE
AWSF-32C / stock heat range - copper plug
AWSF-22C / 1 Heat range colder - copper plug
AWSFA-12C / 2 Hea range cooler - copper plug
AGSF-32C/ Recommended for FRPP heads(not sure on heat range)

NGK

PART# / HEAT RANGE
TR-55/ 3951/ Stock Heat Range
TR-6/ 4177/ 1 Step Colder
BP7EFS (PN - 3526) BR7EF (PN - 3346) two steps
R5724-8 (PN - 7317) two and a half steps
R5724-9 (PN - 7891) three steps
R5724-10 (PN - 7993) four steps

AUTOLITE

PART# / HEAT RANGE
764s / Stock
103s / 1 heat range cooler
AR94 / 2 heat range cooler
AR93 / 3 heat range cooler
AR92 / 4 heat range cooler

CHAMPION

PART# / HEAT RANGE
YS-59C / -3 or -4 below stock heat range

DENSO

PART# / HEAT RANGE
IT16 / stock heat
IT20 / -1 heat range
IT22 / -2 heat range
IT24 / -3 heat range

[black3v4.6]

Thanks for the replies. I am going to swap the stock airbox back in. Then I am going to run over and get new plugs. I have heard I should get the Autolite copper plugs. Are these what you would recommend? Does anyone have the number for the plugs I would need?


How many miles are on your plugs? If they are pretty new I would just inspect them first, if they are high millage then I would just replace them so you don't have to do it a couple of months from now. But it can get expensive just replacing random parts with out knowing what is wrong. You buy 6 or 8 plugs and it could be 50 bucks real fast.

Did you start having the problem right after you swapped intakes? If not its probalby not the problem. I would just do logical steps so it saves you time and money while you are finding the problem. This is where you find out who is a good mechanic. Almost anyone can change a part but its alot harder to find out which part you need to change.

[zombiehouse]

I just saw that someone asked what I drive. It is an 05 4.0 mustang convertible. I installed the CAI in January I think. The problem actually started soon after I installed the dual Magnaflow exhaust. This was a cat back system that added a Y-pipe to the existing one to create an X configuration. As far as I know, the plugs have never been changed. The car has 41K miles. I am going to just change them. Since I am not a trained mechanic, I have found that boards like this are a real asset and many have had the same problems as me so I can get the info here. I definitely do not want to spend money on parts when I don't have to.

[grumps91GT]

Sounds like a A/F ratio problem.

Question:

When you removed you stock mid-pipe and replaced it with the aftermarket one, did you touch the bulb on the 02 sensor with your bare hands or dropped the sensor??


02 sensors are sensitive. Any type of grease on the bulb can cause it to read incorrectly.

[zombiehouse]

When I put in the new exhaust, the O2 sensors were not touched because the original midpipe is left intact. A Y pipe is slid onto the old Y to create a sort of X.

[BondoSHO]

Your problem doesn't sound like an o2 issue. Change out the CAI.

[Nicksbluestang]

clean your t/b

[zombiehouse]

Ok guys, here is the latest update. I think I got the problem solved. I took your advice and checked the spark plugs. I found something interesting when I pulled them out. I had 2 different kinds in the car. On cylinders 1 to 3, I found Motorcraft Platinum 24PGM plugs. On cylinders 4 to 6 I found Motorcraft Platinum 24PM plugs. The 24PGM plugs had a flat electrode tip while the 24PM had a rounded electrode tip. Go figure. Since they were out and they were different I decided to just replace them. I put in E3 plugs in their place. Changing the plugs almost eliminated the sputtering but not quite. I then cleaned the MAF and TB. This eliminated the rest of the sputtering upon acceleration.

Thanks for all your help guys. You saved me a lot of money.