Okay I know everyone and their mom wants to make big fireballs, but I'd like my car to sound fairly normal... and I haven't had a chance to tell yet but I'm guessing I'm not gonna be getting very good mileage either hehe.

For anyone that read my last post, I fixed it (actually I'll go back and describe how I "fixed" it just for other people's reference) and it runs and idles great now. I've noticed maybe once or twice it stumble a little then go back to idling... not sure what that is but it's random and doesn't seem to do anything bad.

So I am running rich I assume because of the popping in the exhaust... never too loud, but if I hold RPMS at 4k I get a perfectly consistent pop-pop-pop-pop. I MIGHT get an O2 code thrown... I cleared the codes and it hasn't come up yet but it came up last night... but I drove through the water last night... so that might have shorted it temporarily.

This is what my car is: S5 N/A with everything stock except... 5/6th port sleeves, a maybe not working rear 6th port actuator (explained below), a corksport catback, a SLIGHT exhaust leak at the pre-cat->cat (both stock... but the pre-cat is gutted... not by choice... that bolt that screwed up my other engine had something it wanted to say to the pre-cat too I guess...) but the leak is VERY small. I see some water dripping out of it or something? It's not coolant, there is no coolant drop at all when I run the car until warm with the cap off (when it starts expanding I put the cap on... no "low coolant warning buzzer" going off even up and down hill)

The actuator on the rear 6th port is a little iffy, I will check it, but during assembly I was testing and it kept getting stuck OPEN if I just blew into it and then let it go... but if I blew in, then sucked the air out it would close... not sure how the vaccum in the nest works, but if it sucks air back then it should be closing fine.

OKAY, if you need any more info ask hahahah... what are the likely causes?

--Gary

 

Sounds like what i had today but dave fixed it, did you set the timing and idle to factory specs? Maybe its the tps?

 

I have the timing set about 2 degrees advanced... could be it... but I'm doubtful it would be this bad. 2 degrees advanced seemed to give me a better idle than normal but I didn't try driving around on it.

I wouldn't count on that being the answer but I'll try it later 'cause it's easy, thanks. =)

TPS is pretty much brand new-used... but I haven't set it! DOH. That is probably a lot to do with it! Haha, I forgot you have to set it.

I'll go read up on how to do that again... thanks haha, dumb of me.

Anything else that can cause the computer to think it needs to run richer?

--Gary

 

if you can get it warmed up and everything set the tps to 1k ohm, today in the morning the car was popping BAD the exhaust was shaking, car was running super rich then after dave fixed it, perfecto

 

i get the same ****...

 

I adjusted my dashpot, fixed it.

 

if water can go out fomr that leak in the exhaust
air can travel through it EASILY

 

I had the same popping in deceleration on my old car... it only happens when car is in gear and I let off the gas(compression braking). It was the tps that wasnt set up right..

 

I can't tell if it's the TPS or not because I couldn't figure out what the heck my AMM was doing... I fiddled around with a few things but couldn't figure out really which wires were the right ones.

I knew before, I just don't know now... anyone know S5 N/A TPS wires off hand? Oh **** nm I remember there's a diagram in the FSM... I'll go check it.

But I think either this TPS (which was supposed to be new-ish) is out or the dashpot might be the problem... it's lookin pretty old.

I noticed the popping is REALLY bad at 3.8k... hmmm?

Either way, it's driveable right now and that's a big improvement.

Except the headlights RANDOMLY turn themselves off... and sometimes just don't work when I turn on the switch. I changed the switch too... it's not that... dunno what else it is, I'll have to find out later.

Found that the rear-iron -> heater core hose is STILL leaking... god damn that hose!! It's leaking at the rear-iron now! I tightened it but no success... I don't think tightening it is the answer now... need to pull that crap off and check out the hose condition... maybe give in and use a squeezing hose clamp instead of the screw-clamp type... grrrr.

--Gary

--Gary

 

EXACTLY what I was thinking. Adjust the dashpot, TPS and timing to factory spec and get back to us, im sure that will fix it.

 

dashpot? what is that?

 

I know what it is but I have no clue how to adjust it, so i would also appreciate this answer. As for the popping, I get 3-4 pops whenever i downshift or decelerate. I just assumed its normal. Sounds badass also.

 

The Dashpot looks like this, to adjust it just loosen that nut and turn it so that the white tip moves closer to the throttle mechanism (if necessary). To test it, open the throttle all the way and let it spring shut, you should see it contact the dashpot and then move slowly to fully closed position from there.

 

...you mean this isn't normal? crap.

 

Thats a TII dashpot, but the NA looks the same, just works a little different.
Adjust it closer so that the throttle plates when snapped shut take a little longer to close.
The dashpot is in a really fixed position, meaning that its is very hard to loosen it, and thus, would not be modified by engine vibration, etc. This means that even after like 17 years, it aint gonna move since the day it left the factory, meaning that adjusting it will be out of factory spec. Something else has changed on the car to cause the problem, not the dashpot. Maybe you should look elsewhere within the fuel system for your problem. Maybe TPS? have you tried adjusting this yet, I havent seen you mention that. TPS over the years can defenitly get out of sync, the screw isn't exactly held in very well, its just a spring that stops it from moving. Over time I could easily see this changing position.

 

It theoretically shouldn't move, whether someone messed with mine or not I don't know, but it wasn't touching the throttle mechanism at any time when I got to it.

 

Mine wasn't even touching at all, I think the previous owner "tuned" it to backfire.

Anyway, this didn't fix the popping... but I think it made it not so bad, I don't seem to get really BIG backfires anymore like when I used to accelerate fast to like 5k then just push the clutch it, it would get little pops and then one BIG pop around 3k. Doesn't do that anymore, so I'm guessing the dashpot catches that one.

Maybe I'll change it back when I get rid of the small pops, 'cause the loud one is badass ;D I know it's horrible for the cat though, so I won't put that back until after smog.

--Gary