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Discussion Starter #1
This might be a little long....
I'm writing this to figure out wtf causes this. I'm not one of those people that just let this go and keep on going, but rather want to know how to prevent it in the future. Would hate for this to happen when I pull away from a stop sign and some idiot not paying attention slams into me.

FYI, I know disconnecting the battery for 30+ min should fix this issue. So this isn't a how to fix it, but what is causing it post.

Had this happen to me a few times weekend after last omw to a track and once randomly omw home the other night.
Was cruising at 80ish on the highway and came up to a red light, pushed clutch in threw the car into neutral, came to a complete stop. Put it into first, and barely anything came out of the motor. Hit the throttle to see if I had just screwed up a shift, and was sputtering and acted like it had 1/2 the power so shut it off(noticed the Tool symbol by the tach was on). Started back up, no problems kept driving for 10 miles or so.
Next red light did the same thing, neutral, coasted to a stop, limp mode again, tool and check engine light came on. Immediately pulled over to the gas station on the other side of the road to check everything. Everything seems fine, no loose wires, CAI intact, ect.
Read the check engine(why you always carry your tuner with you :D) and was throwing a P0100(dirty/faulty MAF). My engine bay has been somewhat dusty because of construction work around my neighborhood, but just a coating, it's not thick or anything like that. We get back in the car start it up, and all is fine again. Keep driving and make it pass one red light w/ no problems. Next one on the other hand, same thing except no check engine, just tool light and limp mode. Turn the car off, start it back up to get moving with traffic and decide since we where just a few miles from the track we will look at it again there. Decided when we get there we'll take the battery off for a while. Forgot to do it since I wanted to make a pass(only made one since track sucked balls) and left an hour or so after that.
Never did it again on our way home(downshifted most of the time whenever we hit a red light, but only hit 1/4 as many). Drove the car to work, part stor and back home with no problems. Got home took maf off, and there wasn't anything on it, but cleaned it anyways. Checked the rag to verify, and not a piece of dust on it. Cleaned the filter, checked the tb, checked the couplers, and made sure all of them were tight when I put them back on. So figured problem solved....
Next day, happens to me again coming to a stop at a red light, tool light, limp mode, stop, start car keep going.
Soooo wtf can it be?
I did get a tank of gas the day before all this happened and the tanker was there. Would bad gas cause this, and only this? No sputtering or anything like that, just dying when coming to a stop.
I have the Boss 302 Manifold w/ JLT CAI. I know there is a fitment issue and I've never had an issue with this before, but I double checked it when I pulled over and when I pulled it off and didn't seem to be any further away from the throttle body than usual. Ordered a longer coupler that'll be here tomorrow and if that's the case, that should be fixed. Could just the JLT be doing this w/ the noisy maf signal it causes and since it's cold, it compounds the problem?
I also have a Lund tune. Could it be a tune issue that only happens in cold weather?
Also have a slipping clutch. But since this is on decel, and not accel don't think it's a factor but never know...

TLDR: Had limp mode happen multiple times on trip, could it be bad gas, cold weather, faulty maf, or just say f it and downshift all the time?
 

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Discussion Starter #3
Faulty MAF?

Dunno man. Could be fuel, guess youll find out after that tank is gone.
Glad you said that, meant to mention I filled up after we got back from our thanksgiving trip with the inlaws and haven't had the issue since. At 1/2 a tank of new gas now.
 

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To be safe go to a parts store and get MAF cleaner. Cheap enough to try. just remove the MAF from the housing, spray down and let air dry for a few minutes.
 

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Discussion Starter #5
To be safe go to a parts store and get MAF cleaner. Cheap enough to try. just remove the MAF from the housing, spray down and let air dry for a few minutes.
Already did. It's somewhere in the post but maf was clean when I pulled it out, and clean when I checked the rag I used.
 

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specially when you tune your car on 93, it might be the gas. I would love to know if that stops, I am planning on getting boss manifold with Steeda, to avoid fitment issues.
 

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Discussion Starter #9
I would stay away from where ever you filled up.
It's the same place I fill up at least twice a month and have never heard of anyone having an issue with them. But I was thinking if it was bad gas, it would stumble some before it went into limp mode, or at least I know it would in an older car.
I kind of intentionally filled up there again to find out if it is bad gas, I know it's asking for trouble, but so far, no problems. Debating waiting to reset it this weekend when I put the new clutch in.

specially when you tune your car on 93, it might be the gas. I would love to know if that stops, I am planning on getting boss manifold with Steeda, to avoid fitment issues.
I like mine except for the fitment issue, but that'll be corrected tomorrow. I like being able to run the car out to almost 8k more than anything :D
 

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You need to data log your car to find out what's going on. I highly doubt it's because your MAF is dirty.
 

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I had this problem and it end up being the line that goes from intake tube to the drivers side valve cover. Itwas making a vacuum leak and causing that code at idle. I popped it back in with a little rtv sealer and problem solved. Try checking for leaks.
 

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Discussion Starter #12
You need to data log your car to find out what's going on. I highly doubt it's because your MAF is dirty.
I wanted to datalog, but that means I'd have to have the laptop on and running every time I got in and out of the car since it doesn't happen constantly. I might do it tonight if I get some free time to ride around town.

I had this problem and it end up being the line that goes from intake tube to the drivers side valve cover. Itwas making a vacuum leak and causing that code at idle. I popped it back in with a little rtv sealer and problem solved. Try checking for leaks.
Will check again tonight. I do have the JLT oil separator, so I could have not tightened it all the way down as well.
 

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This is a bit random...but I just keep finding mixed reviews on the Internet.

Is the Boss Intake worth it? a lot of people are saying you won't see the difference until you go over 7k rpm and you end up losing some torque anyway...
 

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Discussion Starter #14
This is a bit random...but I just keep finding mixed reviews on the Internet.

Is the Boss Intake worth it? a lot of people are saying you won't see the difference until you go over 7k rpm and you end up losing some torque anyway...
Yes and no. It really depends on what you plan on doing with the car. If you want to leave it N/A, it'll hurt your low end power like you said. Few members on here have used it at the track and are consistent enough to know when something helps or hurts, and they say it hasn't helped them at all. But, if you want to put a centrifugal s/c or nitrous on it, that's where it'll help out because they will make up for the lost low end power and it'll help gain more on the top end.

Now, if you really want a new manifold without losing any power down low, and gaining even more on the top end than the boss.... Cobra jet manifold FTW. There are a few things to remember with it though... gotta have GT500 tb, custom intake(unless someone finally designed one) and I'm not sure any tuners out there have a canned tune for it(but something like this should probably be dyno tuned anyways). And it costs twice as much as the boss one, for just the manifold.
 

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Oh wow. Thanks so much. I have never seen that intake manifold. Will keep this in mind.

All my mods are just suspension...I have been thinking about doing the intake/tune but I just feel like the stock set up is fast enough. I just have to do more research on which tune and just in genearal what to watch out for when adding power.

I hope you find your problem!
 

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I had a similar issue due to my tune. The tune wasn't accounting for the steeda air intake. As it has a bigger intake opening. Once the tune was fixed the problem went away. I"m bringing this up as you have the boss intake. Maybe the tune is missing something? Car did exactly what you said. Ran fine, stopped at a red light and the car pretty much shut down. Barely had any power, pulled over thinking wtf is going on here. Turned off the car and started it back up. Ran fine. Had the tune looked at and found the missing information. Fixed that, never had another issue.
 

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Whiskey??
 

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Discussion Starter #18
I had a similar issue due to my tune. The tune wasn't accounting for the steeda air intake. As it has a bigger intake opening. Once the tune was fixed the problem went away. I"m bringing this up as you have the boss intake. Maybe the tune is missing something? Car did exactly what you said. Ran fine, stopped at a red light and the car pretty much shut down. Barely had any power, pulled over thinking wtf is going on here. Turned off the car and started it back up. Ran fine. Had the tune looked at and found the missing information. Fixed that, never had another issue.
I've had all these mods with a tune for them since May, and this just started happening.
 

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I had this happen as well. Car ran fine at speed but would stall at idle. Turned out that one of the fittings on my JLT separator had snapped and was causing a vacuum leak. Called JLT and they sent me the aluminum replacement and all has been good.
 

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Discussion Starter #20
Just an update, but this hasn't happened again since that day/tank of gas. Checked all my fittings and everything and nothing seemed to be loose so going to chalk it up as dirty gas I guess.
 
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