Update to Surging/Bucking.

95_XR7

Registered User
I have checked, and replaced Camshaft Sensor and the pigtail. (The connector was broke and would come loose.) I have checked the HB and see no wobbling during running conditions, or even starting.

I have checked various connectors, etc.

The problem is, during startup, the car will usually surge, and smooth out, or it will die. I also get surging while driving the car. The surging usually occurs after I drive the car for a bit, and then say..go in somewhere and eat, and then go and drive it again. After a short cool down. I've also had the car start surging while it's raining outside. (I know, bad idea to drive my birdy in the rain, but it wasn't my fault.)

I've also noticed the car seems to do the whole surging/bucking UNDER electrical load. For example, if I roll down both windows, and then let off the buttons, it'll surge. It surges sometimes if I turn the panel or A/C on. I've also been noticing problems with the amp going into 'Protection.' mode frequently.

The surging is enough to cause my firm ride to activate, and it can even sometimes clear my Check Eng. codes.

I am thinking electical, but I have no idea where to look. I've checked various grounds, pigtails, and harnesses, but I'm clueless.



EDIT: I've also noticed a problem with the car revving while putting it in Park. :|
 
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Sounds like the computer is trying to relearn the idle. It sounds like your PCM is losing power and resetting its memory. Is your battery good? Check all connections to make sure they are clean and tight. You may also have a problem with the power or ground for the PCM.
 
Have you replaced the DIS module lately?

I just did cam and crank sensors, dis, and coil pack. My car runs awesome now. It was surging and wanting to die.

My DIS was shot no doubt. The cam sensor was probably fine but I changed it anyhow it was only 2 years old. The crank sensor was only 1 year old but I changed it. It had some rubbing on it like the balancer ring rubbed it, I might not have aligned it perfect last year.

The car lost tach signal and then the tach came back to life. The DIS and cam sensor run the tach. But since it would start right up I figured the cam sensor was still good.
 
I was thinking DIS, but when it actually surges, it loses spark to all 6 cylinders, and the pcm sometimes loses power and resets itself.

Also I usually see the lights dim and all that.
 
How about your ignition switch? That would control power to almost everything. Many people have had theirs come apart and lost power intermittently.
 
Haven't had a chance to check the car, as I have school and work shortly thereafter.

Tonight, while going through town I found a Mustang to pick on. I think the guy ****** himself when I stepped on it next to him, and all you hear is blower whine.

After running the car with him pretty hard, I noticed it was doing it about every 2 or 3 seconds.

So I know the problem does not like electrical load, it does not like heat, and it doesn't like it when the car is ran hard?

I'm kinda thinking it may be more than one problem. :rolleyes:
 
Rule out the ignition switch. I replaced that in December chasing the intermittent no start problem.

I would go through the electrical system very well...sounds like it could be a bad ground or even a bad positive feed to the main breaker box. Check the connection on the back of the alternator as well. I have heard of these corroding and it sounds like any other engine load is making the problem worse.

I think you can pretty much rule out the HB. This definately sounds electrical in nature. Maybe rig up a digital voltmeter to the battery or certain points you suspect as bad....watch it while driving and if it surges and registers on the voltmeter, then start from that point and work backwards.

Electrical gremlins are a hard thing to chase and can be very frustrating. I'm sorry to hear you are having problems with the car. If I would have known it was going to start acting up, I never would have sold it to someone. Best of luck with things Corey...I'll do what I can to help. :cool:

-Trey
 
Rule out the ignition switch. I replaced that in December chasing the intermittent no start problem.

I would go through the electrical system very well...sounds like it could be a bad ground or even a bad positive feed to the main breaker box. Check the connection on the back of the alternator as well. I have heard of these corroding and it sounds like any other engine load is making the problem worse.

I think you can pretty much rule out the HB. This definately sounds electrical in nature. Maybe rig up a digital voltmeter to the battery or certain points you suspect as bad....watch it while driving and if it surges and registers on the voltmeter, then start from that point and work backwards.

Electrical gremlins are a hard thing to chase and can be very frustrating. I'm sorry to hear you are having problems with the car. If I would have known it was going to start acting up, I never would have sold it to someone. Best of luck with things Corey...I'll do what I can to help. :cool:

-Trey

No worries about having problems. The only real problem is I am kinda unsure where to start, because at first I thought it was a sensor, as that's what it sounded like, and then new symptoms arise, and then it's off to think some more.

Don't worry it man, really I enjoy the car man that I am mad at it. It's just...I am worried with it doing it in the rain sometime. Engine load, then no power, and then power again is a perfect way to spin the tires. Not good.

I am off tomorrow, but have school, so I may be able to check some things out in the evening.

Also, thanks for the help gentlemen, and thanks Trey. I may be giving you a call tomorrow, I have one more question. :p
 
Corey,

Also when you get a chance pm me or e-mail me your mailing address. Apparently I put the wrong one on the package I owe you because I got it back in the mail a couple days ago...probably my mistake. :eek:

-Trey
 
Hmm. This just came to me, but as I'm without the car for now. (I have it at my brother's shop sitting up on the lift all by its lonesome. :( ) I'm mocking up the exhaust, trying to figure out how to fit these massive Borla's underneath there and not rub on anything, or use TIGHT bends.

I've checked over wires lately. Haven't hit alot of them, but I've completely gone over just about every wire. (Removed the wrap and tape, and redone it.)

Do you think the TPS could cause this? Maybe a short in the wiring? That'd cause the surge while starting, and the surge while putting in park?

Just an idea.
 
Corey-

Post up on the forums and see if you can find someone with an extra DIS laying around. I don't think you have ruled that out and these are symptoms that could be associated with it going bad. I do not know if there is a test for it or not.

Someone just recently posted about having similar problems to yours only bad enough to the point where the car wasn't driveable. The problems disappeared at WOT because the computer goes into open loop. Have you ever had these problems at WOT? If not, it may be worhtwhile to check it out. And if it doesn't solve it, you can always return it....this one even has lifetime warranty.

http://www.autozone.com/Ntt,f136/shopping/allResults.htm

P.S. - don't forget the grease!

-Trey
 
Corey-

Post up on the forums and see if you can find someone with an extra DIS laying around. I don't think you have ruled that out and these are symptoms that could be associated with it going bad. I do not know if there is a test for it or not.

Someone just recently posted about having similar problems to yours only bad enough to the point where the car wasn't driveable. The problems disappeared at WOT because the computer goes into open loop. Have you ever had these problems at WOT? If not, it may be worhtwhile to check it out. And if it doesn't solve it, you can always return it....this one even has lifetime warranty.

http://www.autozone.com/Ntt,f136/shopping/allResults.htm

P.S. - don't forget the grease!

-Trey

I appreciate the help. Before I noticed your post, I checked the wiring to the TPS and guess what I found? Bare wires. Didn't fix my problem but hey, fixed something else. :p

Yeah, I hate to drop the money for the DIS when it could go to performance parts instead..but I've been debating it this last week.
 
Check these...working on mustangs alot of surging and bucking happens and people usually check the ground straps engine to frame on the passenger side front of the engine to the passenger side frame right near the airbox check the ground connects make sure there free of corrosion if not clean'em up put'em back on ...the spot where it attaches to the frame on my car there was paint on it from the factory I dont see how it could get a good connection my headlights are brighter now...lol also check the connections to the alternator they get corroded as well and also check the large wire that runs to the engine fuse block from the alternator there is a large fuse there that gets corroded and the one on the other side of the fuse to the battery ...also check the harness connector on the right side of the engine bay near the firewall pull it apart clean the connections out with a wire ...you should be okay after that ...only other thing is a weak alternator or battery might wanna have them bench tested...make sure after you clean those connections you put fresh dielectric grease all over them where metal touches metal...you should be good these have caused numerous problems with mustangs surging and bucking
 
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Hey blown94, thanks for the advice. Haven't had much time to check out the car. It seems every day I have off, I get called in. :rolleyes:

Anyways, tried a different DIS and I THOUGHT that had fixed it, but it seems to not be the problem. However, it's not surging as much now? :confused:

Tomorrow the new battery should be here, because I planned on relocating it to the trunk anyways. However, the cable has still not shipped, so not sure when I'll be able to get that done.

Also, trying to get the exhaust finished too..stupid Borla mufflers are 14in's long, and I can't seem to figure out how to bend the pipe, keep it away from the swaybar, and keep the mufflers away from the bumper cover. I guess I'm gonna have to go with a kinked 90* bend.

ANYWAYS...on topic. Tonight I bought some Monster Energy drinks, and I plan on going over all the grounds, griding down to bare metal, etc...running new wire to see if it helps. I also plan on doing the Big 3 once the stupid cable gets shipped. I'll get it done even if it means going to school with grease all over me. :p
 
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Two posts in a row, so I apologize.

I checked motor mounts, and there seems to be a LITTLE bit of play. Not sure how much play is fine with the solids. Also, whenever the car seems to surge at idle, right BEFORE it does it tilts to the side, and then it starts to stall/surge.

I also noticed Trey had already gone over some of the grounds, atleast all the small ones uptop.


Also, included is a picture of the oil filter...something doesn't seem right, as that filter is pretty snug up against the looms, and k-member.

Car



Off-topic, but this doesn't look too good does it? K-member is bent and cutting into the strut rod bushing.

100_4124.jpg
 
I think the position of the oil filter might be ok. I get my oil changed at a Pennzoil sometimes, and the filter they use seems to be a good bit taller than the stock Motorcraft filter or the Fram replacements I sometimes buy (I love that grippy bottom!).

It does sound like you may have a loose wiring connection, whether it be a ground or a sensor hookup. Maybe it flexes just enough to cause problems when the motor tilts under the torque of revving.

Oh yeah - and the K-member shouldn't be doing that, LOL. Maybe you can heat it a little and vise-grip it back into shape.
 
If the motor is tilting that is a good chance for a problem. Once it tilts it hit a stop in the mount, and fools the anti-knock sensor into thinking the timing is too far advanced and you are getting detonation, therefore the computer retards the timing.
 
Well, a lot of tilt is bad, but it will tilt when you rev. How much is too much? I don't know how to say. It shouldn't make a CLUNK noise, that's for sure. You can also try revving it in reverse and drive to stress each side motor mount.
 
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