I Found a vacuum leak - But the car says: "HA! Just kidding!"
06-23-08, 12:34 AM
#1
I Found a vacuum leak - But the car says: "HA! Just kidding!"
It's a ***** sometimes...
[before anyone DARES ask, yes I searched...]
Ok, it's an 87' Base, automatic..
Drove 30 min. then up a big hill/mountain [high enough to see the whole Portland/vancouver area]. And then after I started it again the idle was jumping between 700-900 [Auto's are supposed to idle at 950, which it usually does fine]
Then driving last night I noticed it wasn't just the idle that was suffering, it was the power - took more pedal action to get from 50-65 than it should..
idling today I could hear that it was kinda rough.. I checked the spark plugs [seemed normal..], checked that the wires were getting power right up to the plugs, changed the TPS for another known good one, so I'd gathered it to be a vacuum leak.. Ok.
So I sprayed around.. Didn't notice anything the first time, so I sprayed it into the intake [by this point I'd gotten frustrated enough to try taking out the airfilter so it was directly into the filter's box]... and the car idled beautifully for a couple seconds..
So I sprayed around some more thinking i'd missed the leak and found that when I sprayed onto the part of the UIM where the two little vac. lines connect from the rat's nest that it idled nicely again..
So, naturally I thought "Yay, found the problem!"
and swapped out the vac. lines.......... To no effect.
with nothing left to do, I destroyed a couple RainX boxes and thought a lot more about buying the NC MX-5 I test drove today, or the RX-8 that they offered me for 19K [New, 08']
:P
So, keep me from caving to the temptation of 6 years of car payments - help please.
[before anyone DARES ask, yes I searched...]
Ok, it's an 87' Base, automatic..
Drove 30 min. then up a big hill/mountain [high enough to see the whole Portland/vancouver area]. And then after I started it again the idle was jumping between 700-900 [Auto's are supposed to idle at 950, which it usually does fine]
Then driving last night I noticed it wasn't just the idle that was suffering, it was the power - took more pedal action to get from 50-65 than it should..
idling today I could hear that it was kinda rough.. I checked the spark plugs [seemed normal..], checked that the wires were getting power right up to the plugs, changed the TPS for another known good one, so I'd gathered it to be a vacuum leak.. Ok.
So I sprayed around.. Didn't notice anything the first time, so I sprayed it into the intake [by this point I'd gotten frustrated enough to try taking out the airfilter so it was directly into the filter's box]... and the car idled beautifully for a couple seconds..
So I sprayed around some more thinking i'd missed the leak and found that when I sprayed onto the part of the UIM where the two little vac. lines connect from the rat's nest that it idled nicely again..
So, naturally I thought "Yay, found the problem!"
and swapped out the vac. lines.......... To no effect.
with nothing left to do, I destroyed a couple RainX boxes and thought a lot more about buying the NC MX-5 I test drove today, or the RX-8 that they offered me for 19K [New, 08']
:P
So, keep me from caving to the temptation of 6 years of car payments - help please.
06-23-08, 01:29 AM
#2
Where exactly did you spray? On the 2 nipples that come off of the LIM (right above the ACV), and then connect to the rats' nest hardlines near the firewall? (circled in yellow. Ignore the UIM in the pic, it's S5, but the LIM is S4)
That area is right where the UIM/LIM gasket is as well, how old is the gasket? Bordering on ancient? Try to spray in really specific spots so you can narrow it down.
That area is right where the UIM/LIM gasket is as well, how old is the gasket? Bordering on ancient? Try to spray in really specific spots so you can narrow it down.
06-23-08, 01:50 AM
#3
Yea, I sprayed right at those two.. [you're right, it was the LIM]
The gasket is pretty new [Aug. 07].. So it seems pretty unlikely to be that..
I'm not sure if I can narrow it down anymore more than to just around those two.. I sprayed around about where your circle is, and only got it to smooth out on those two.. [doesn't happen if I spray that other vac line that goes to the "boost" sensor on the pass.strut tower]
The gasket is pretty new [Aug. 07].. So it seems pretty unlikely to be that..
I'm not sure if I can narrow it down anymore more than to just around those two.. I sprayed around about where your circle is, and only got it to smooth out on those two.. [doesn't happen if I spray that other vac line that goes to the "boost" sensor on the pass.strut tower]
06-23-08, 04:49 AM
#5
lol.. it'd be easier if it were an MX-5 with a Renesis.. I've got too many friends to carelessly buy a car with 4 seats [not to mention, I like the {Kouki}FC lines better than any other car's... ^_-]
But then.. a new $19k 8' is a freakn good deal.. [I think it's because they're clearing out the Zenki RX-8s for the 09' model Kouki RX-8s.. ]
in anycase, this FC is still my DD... [the FB has an oil leak and most of the gauges don't work most of the time...] and the /secret project/ isn't ready yet either.. [hopefully next weekend though ^_- *hint hint*... if you read this, you know who you are.... Please
?]
But then.. a new $19k 8' is a freakn good deal.. [I think it's because they're clearing out the Zenki RX-8s for the 09' model Kouki RX-8s.. ]
in anycase, this FC is still my DD... [the FB has an oil leak and most of the gauges don't work most of the time...] and the /secret project/ isn't ready yet either.. [hopefully next weekend though ^_- *hint hint*... if you read this, you know who you are.... Please
?]
06-23-08, 01:08 PM
#6
It could be the ACV gasket is leaking, but that usually just ends up with an exhaust leak. I've found soot on the boost sensor vac line from a leaky gasket there before. I'd guess it would be possible to get a vac leak from that area too since the anti afterburn valve is vacuum fed and routed through the ACV. Seal it up with some RTV just in case that's the problem.
06-23-08, 03:44 PM
#7
Okey, I'll pull it off and try that.
Do you think it could be the airflow sensor? [since the problem seems to be that it isn't injecting enough fuel]
or maybe fuel filter?
I didn't drive to work today, it was losing power even worse today than on saturday..
Do you think it could be the airflow sensor? [since the problem seems to be that it isn't injecting enough fuel]
or maybe fuel filter?
I didn't drive to work today, it was losing power even worse today than on saturday..
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06-23-08, 05:04 PM
#8
Honestly, it sounds like something more than just a vac leak, though it sounds like you might have one of those also. Vac leaks don't make you lose power. When the trottle is opened, the vac leak is basically negated since there really isn't much vacuum. I've had a vac leak for quite a while (gouged intake manifold gasket surface.....) and its not losing power. I can't think of something that would cause it to idle like that right now, but if I do I'll post it.
06-23-08, 05:08 PM
#9
:/
I'm sure it's a lack of fuel [I just don't know why].. it idles perfectly when I spray the starter fluid into it..
It shouldn't be the injectors [they were professionally sonic cleaned by Dr.Injector's], could be the fuel filter [been meaning to replace it]
Shouldn't be compression [rebuilt the engine in Aug, been driving it since sept.]
I could try swapping out the plugs and fuel filter - think it'll help?
I'm sure it's a lack of fuel [I just don't know why].. it idles perfectly when I spray the starter fluid into it..
It shouldn't be the injectors [they were professionally sonic cleaned by Dr.Injector's], could be the fuel filter [been meaning to replace it]
Shouldn't be compression [rebuilt the engine in Aug, been driving it since sept.]
I could try swapping out the plugs and fuel filter - think it'll help?
06-23-08, 05:20 PM
#11
I'm very confident that it's not the cat.. the cat is new as of ~aug. [and the exhaust isn't well sealed to the manifold - there's only one stud holding it on]
The car actually ran pretty well before I changed the cats to a single cat.. They were pretty well clogged..
The car actually ran pretty well before I changed the cats to a single cat.. They were pretty well clogged..
06-23-08, 07:28 PM
#12
Well, if we rule out a vac leak or a clogged cat, there aren't many other things it could be.
Make a code checker and see if there are any disfunctional sensors.
Check that the TPS is set at 1 volt when warm. And check that adjusting the mixture has no effect. Any time I've had a bouncy idle it was due to a mistadjusted or bad TPS, if not a vac leak.
As for the power loss, what RPM range was it acting sluggish? I'm guessing midrange to topend depending on what gear you were in. First thing to check is the throttle cable, since a loose cable will not let the throttle plates open all the way. And the throttle cable shifting the plate's resting position will change the TPS value at idle. When I had this happen, I didn't notice power loss down low, but topend was severely weakened. I just didn't tighten it up enough after I swapped my manifolds.
Other than that...secondary injector issues? I don't think the AFM would affect power, but it can make your idle turn to crap. You can always test the resistance as per the FSM.
Make a code checker and see if there are any disfunctional sensors.
Check that the TPS is set at 1 volt when warm. And check that adjusting the mixture has no effect. Any time I've had a bouncy idle it was due to a mistadjusted or bad TPS, if not a vac leak.
As for the power loss, what RPM range was it acting sluggish? I'm guessing midrange to topend depending on what gear you were in. First thing to check is the throttle cable, since a loose cable will not let the throttle plates open all the way. And the throttle cable shifting the plate's resting position will change the TPS value at idle. When I had this happen, I didn't notice power loss down low, but topend was severely weakened. I just didn't tighten it up enough after I swapped my manifolds.
Other than that...secondary injector issues? I don't think the AFM would affect power, but it can make your idle turn to crap. You can always test the resistance as per the FSM.
06-23-08, 08:46 PM
#13
I'm not sure if ruling out the vac leak is correct at this point..
Clogged cat is out though [the car would be nice and quiet and give my ears a break..]
code checker?
I'd like to eliminate the TPS.. I switched TPSes with no effect..
How would I adjust the mixture [do you mean the idle speed screw?]
The power loss is mostly in the low end, but still present in the mid range [high end felt about normal]
when I drove around the court this morning, it would start stuttering badly/slowing down <2k, and I could still hear it running weird above that..
I've got another AFM [two actually...] that I could try on it..
I'll go reseal the ACV now and come back in a bit and let you know if that worked.. [if it doesn't I might drop the other AFM in there..]
Clogged cat is out though [the car would be nice and quiet and give my ears a break..]
code checker?
I'd like to eliminate the TPS.. I switched TPSes with no effect..
How would I adjust the mixture [do you mean the idle speed screw?]
The power loss is mostly in the low end, but still present in the mid range [high end felt about normal]
when I drove around the court this morning, it would start stuttering badly/slowing down <2k, and I could still hear it running weird above that..
I've got another AFM [two actually...] that I could try on it..
I'll go reseal the ACV now and come back in a bit and let you know if that worked.. [if it doesn't I might drop the other AFM in there..]
06-23-08, 10:45 PM
#14
Definitely set the TPS. There are directions in the FSM on how to do it with a multimeter. You use the light method, but instead just check for voltage with a meter. There are 3 spades in the check connector (green connector by pass shock tower if memory serves.) One is ground, the other two have voltage (either 12V or 1V) depending on where the TPS is set. You want there to be voltage on one and not the other when the car is warmed up at idle.
My car had a misaligned TPS, and it ran like **** before I fixed it.
My car had a misaligned TPS, and it ran like **** before I fixed it.
06-24-08, 02:34 AM
#15
Ok, update:
I swapped out AFMs [cone filter adapted AFM vs stock airbox w/AFM], coated both sides of the ACV gasket with black RTV, and stuffed the fastener for the airpump to ACV all the way down [I was feeling air moving in the area where they connected and the little wire thing wasn't all the way on like it should be - I don't feel air there anymore]
Spraying starter fluid at the vac lines/ACV area no longer has any effect, and it's still running poorly..
Sideways7 -> How could it be the TPS when I swapped out for another one that was working perfectly?
I listened carefully on a drive today [after the work I did to test it], and it runs poorly until the secondary injectors kick in..
So, for one reason or another, one and or the other primary fuel injector are putting out too little fuel for the air it's getting..
[It still smoothes out when I spray starter fluid on the air filter..]
haven't swapped fuel filters yet..
I swapped out AFMs [cone filter adapted AFM vs stock airbox w/AFM], coated both sides of the ACV gasket with black RTV, and stuffed the fastener for the airpump to ACV all the way down [I was feeling air moving in the area where they connected and the little wire thing wasn't all the way on like it should be - I don't feel air there anymore]
Spraying starter fluid at the vac lines/ACV area no longer has any effect, and it's still running poorly..
Sideways7 -> How could it be the TPS when I swapped out for another one that was working perfectly?
I listened carefully on a drive today [after the work I did to test it], and it runs poorly until the secondary injectors kick in..
So, for one reason or another, one and or the other primary fuel injector are putting out too little fuel for the air it's getting..
[It still smoothes out when I spray starter fluid on the air filter..]
haven't swapped fuel filters yet..
06-25-08, 02:33 AM
#18
:/ I am running out of things to do, but I doubt it's an injector...
These were [again in Aug] sonic cleaned/tested.. and I've only been using Chevron gas since then [back when I first got the car, I used Arco.. tsk tsk old me.. but when I stopped using Arco the car stopped flooding..]
Tonight:
I changed all of the 3.5mm vac lines and a couple of the larger ones [3.5mm stuff is all new, the couple large ones I swapped were spare that DID NOT HAVE PROBLEMS]
That didn't work.
So I changed the fuel filter [I've had a new one I've been meaning to install for a long time..]
That didn't work.
So I listed to the pulses [why not.. Running out of things to go wrong..] Sounded normal..
I also swapped out that thing.. blanking on it - on the driver's side of the dynamic chamber, that attaches to a tube that eventually connects to the big air intake..
Yea, that didn't work either
Think it could be the pump? Really....? [Does that make sense if the car's high end is still working great?]
These were [again in Aug] sonic cleaned/tested.. and I've only been using Chevron gas since then [back when I first got the car, I used Arco.. tsk tsk old me.. but when I stopped using Arco the car stopped flooding..]
Tonight:
I changed all of the 3.5mm vac lines and a couple of the larger ones [3.5mm stuff is all new, the couple large ones I swapped were spare that DID NOT HAVE PROBLEMS]
That didn't work.
So I changed the fuel filter [I've had a new one I've been meaning to install for a long time..]
That didn't work.
So I listed to the pulses [why not.. Running out of things to go wrong..] Sounded normal..
I also swapped out that thing.. blanking on it - on the driver's side of the dynamic chamber, that attaches to a tube that eventually connects to the big air intake..
Yea, that didn't work either
Think it could be the pump? Really....? [Does that make sense if the car's high end is still working great?]
06-25-08, 05:52 AM
#19
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- i just had the same symptoms and it turned out everything in the fuel path was dirty (stupid original owners)
-doesn't sound like the pump-
i'm out of things to suggest
-doesn't sound like the pump-
i'm out of things to suggest
06-26-08, 05:45 PM
#21
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Definitely set the TPS. There are directions in the FSM on how to do it with a multimeter. You use the light method, but instead just check for voltage with a meter. There are 3 spades in the check connector (green connector by pass shock tower if memory serves.) One is ground, the other two have voltage (either 12V or 1V) depending on where the TPS is set. You want there to be voltage on one and not the other when the car is warmed up at idle.
My car had a misaligned TPS, and it ran like **** before I fixed it.
My car had a misaligned TPS, and it ran like **** before I fixed it.
07-02-08, 12:04 AM
#22
Like I said, it couldn't be a bad TPS..
Anyway, I finally met up with Marc today, and it took all of 5 min. to fix..
In my frustration, I'd forgotten about a broken 3-way vac connector I'd broken when I was replacing the lines.. [I'd assumed at the time that it wasn't the problem, because I plugged it with my finger...]
Thanks for all the help guys!
Anyway, I finally met up with Marc today, and it took all of 5 min. to fix..
In my frustration, I'd forgotten about a broken 3-way vac connector I'd broken when I was replacing the lines.. [I'd assumed at the time that it wasn't the problem, because I plugged it with my finger...]
Thanks for all the help guys!
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