Trouble with exhaust back pressure.

[HaoleBoysClipse]

First, I was wondering if some springs that I bought for my 1998 Eclipse GS, but the box said AWD, will fit on my car without any mods? Next, I was having a problem starting my car. I changed my plugs and wires and also my fuel filter. After that i still had the problem. I put some duct tape over my exhaust and it started right up. It has been a couple weeks working fine until today. I had to do the tape trick again. Any ideas on what is causing this problem? Also, do you think that an exhaust silencer would keep enough exhaust pressure in the system so I dont have to worry about the tape method? Thanks alot.

 

[nightspeed87]

Huh??? what are you talking about? Why do you want more back pressure? Especially if you have a stock exhaust system... Backpressure isnt considered a good thing......... Are you saying your car isnt starting up until you put "tape" on your exhaust, Im sorry I just dont understand, and I dont think anyone will. What exactly is your car doing thats making you conclude to what your doing.
And let me add one more thing, what size drop are those springs your talking about because if there too low then your going to need the entire struts package, which you most likely need anyways, and about them being awd springs I dont know if the awd strut system is different even though i doubt it will be. It should work, mayone someone else can verify that.

 

[HaoleBoysClipse]

Sorry if it sounds confusing. My car runs fine. But sometimes it will not turn all the way over. So, I place tape over my exhaust tip or I stuff something in there. Once I do that, it starts right up. It seems as if i'm loosing pressure or something but i'm not exactly sure.

 

[jastermerrel]

Guten Tag!

I dont see how putting tape over the exhaust opening could have any effect on your car starting up...if anything I think that it would impede it. I'd look elsewhere to the starting up problem. When you say that sometimes it wont turn over all the way, do you mean that the engine will not spin all the way...as in make a full revolution? Sounds like a starter area issue, perhaps a solenoid or the starter itself. Maybe even the battery or a loose connection somewhere.

 

[MMM]

Huh??? what are you talking about? Why do you want more back pressure? Especially if you have a stock exhaust system... Backpressure isnt considered a good thing.........

In his case, he does need packpressure and the right amount is considered a good thing (his profile says he has N/T) but there is NO WAY lack of backpressure will not allow the car to turn over. I have fired up cars open headers many of times, shit I have even fired a car open head hahaha. Describe EXACTLY what your car is doing.

 

[PieEyedPiper]

In his case, he does need packpressure and the right amount is considered a good thing (his profile says he has N/T) but there is NO WAY lack of backpressure will not allow the car to turn over. I have fired up cars open headers many of times, shit I have even fired a car open head hahaha. Describe EXACTLY what your car is doing.

Wrong.

http://dsmtuners.com/forums/showthread.php?t=168578

 

[MMM]

Okay, that post (and you) are absolutly correct. I use the term backpressue loosly. You need the right sized pipe to match your engine.

 

[kenamond]

But for whatever reason, increasing backpressure in this guy's car helps him start it, so does anyone have any ideas what problem might exist that is fixed by capping the exhaust? Poor compression? Bad plugs?

 

[99gst_racer]

Moved to 420a Bolt-on Tech.

 

[4UH8ERS]

But for whatever reason, increasing backpressure in this guy's car helps him start it, so does anyone have any ideas what problem might exist that is fixed by capping the exhaust? Poor compression? Bad plugs?

Turn the key in the ignition to the on position without cranking the motor over. do it like 3 times before actually trying to start it and tell me if it fires up.

 

[bullettdsm]

OK, I'll bite. How did you come up with the idea to even cover your exhaust? Not being a wise-ass or anything, but it may help us understand the problem. If my car won't turn over, the thought of covering my exhaust just doesn't come to mind.

MB

 

[DSMcrazy3]

As for the springs, an AWD set is a no go. They are made to support the extra weight. N/T or GS-T springs will be fine.

 

[HaoleBoysClipse]

I described the problem to somebody and they told me to try covering it. But the guy has moved and I wasnt able to ask him the reason why.

 

[Defiant]

This may well be the most bizarre thread I've ever read on DSMtuners.

How would this mythical "back pressure" have an effect on a compressing fuel/air mixture that's sealed in a cylinder by the exhaust valve? I can see it having an effect on running, cylinder scavenging, and torque characteristics across the rev range, but surely not at the 600 rpm a starter turns a crank.
Back the the carburetor days, it was common we'd slap a palm across an intake horn during cranking to get a good blast of fuel into the manifold (and get the vacuum up into the carb), but I've never heard of blocking an exhaust to get things going. And sure as hell not with tape.
Wow.

Maybe it's still some kickback from that whole EU thing.

 

[HaoleBoysClipse]

Well my car is a U.S. spec vehicle. I'm just stationed in Germany. And yeah, I have no idea either. Thats why i'm here. I thought atleast one other person would have had this problem. Not only have I used tape but i have put a paper cup in there also and it started right up and shot the cup out.

 

[dr1665]

I would suggest heading over to the base hobby shop, putting the car up on a lift, and inspecting that exhaust system. Maybe you hit a bump and somehow damaged the piping somewhere. If the exhaust looks fine, disconnect the exhaust after the catalytic convertor and try starting it. If the problem is still there, remove the cat too. This would be the simplest way to troubleshoot this one, imo.

I don't see how the muffler thing can have anything to do with starting, but if you remove part of the exhaust and the problem goes away, I'll be damned. WTF

I tried starting my car once and a buddy had put his foot into my no longer installed fart cannon muffler. The car struggled to start and then nearly died until he took his foot out. Blocking the muffler should make the car run worse or not at all.

 

[HaoleBoysClipse]

Yeah, i'll try that. I havent changed my cat or headers yet in the 4 years ive had the car but i have got a newer cat back exhaust. I thought maybe I have a exhaust leak or something.

 

[DSMcrazy3]

Even an exhaust leak wouldn't cause the car not to start...As stated many people start the car open headers etc... With no problems.

 

[HaoleBoysClipse]

Yeah, you r right. I'm just clueless. Maybe its time to get rid of it and look for a turbo model.

 

[bullettdsm]

Yeah, you r right. I'm just clueless. Maybe its time to get rid of it and look for a turbo model.

Whoa, whoa! Now don't go talkin' all foolish !

Ok, you kind of got me on this one, but I'm going to point to something that Brian was alluding to. Pull the cat and see if you have some blockage in there or if there is a lot of "loose" stuff in there. Possibly something in the cat is blocking the pathway and when you block off the exhaust it.............Well, just take a look anyway.

MB