Stalling between gears.

[Kevin TSI]

Ok I am looking at a 93 talon tsi. Here is a list of the mods.

6 bolt
b/s removed
new rebuilt head with cometic gasket and arp studs
new comp 101 cams
pte 680cc injectors
johnnyracecar IC
homemade IC tubing
2nd gen MAS
Dejon Intake
Hahn S20g turbo
S-AFC 2
Datalogger
Fidanza Flywheel alum
TRE performance tranny
ACT 2600
autometer guages
aeromotive afpr
255 walbro
new d/s front cv axle
thermal catback 3in
megan 3in downpipe

It is stalling between gears and also when I was coming to a stop. It does it every time so I don't think it is just because of the flywheel and cams. Could it be the CAS, bad battery connection or something else? I am going back to look at the car again but I need to know what to look for when I go.

 

[hereitcomes]

How does your vaccum look at idle? if its anywhere below 16 and fluxuating you may have a bad boost leak. Also, are you recirculating your BOV? A vented BOV can lead to engine stalling and poor performance.

 

[Kevin TSI]

How does your vaccum look at idle? if its anywhere below 16 and fluxuating you may have a bad boost leak. Also, are you recirculating your BOV? A vented BOV can lead to engine stalling and poor performance.

Vacuum was surging from 15-20 if I remember correctly. BOV is recirculated.

 

[Kevin TSI]

Also the coolant light and the check engine light are on. If anyone has any ideas please let me know because I need to know if this car will run right before I sell mine saturday.

 

[Gs Dewd]

Check your idle if it's to low it will stall. Mine was doing that Sat and just raised the idle a tad and it's good to go.

 

[98eclipsekidd08]

My car was just doing this because i got a 3in exhast without a cat. I made a o2 sim. works better but my idel is still a bit messed up. No more stalling tho

 

[Kevin TSI]

Could we try resetting the ECU?

 

[snafer100]

i am the guy the owns this car that Kevin is talking about, It only stalls after warming up. I seen in another post somone stating that with the low coolant light it will think the car is always cold???? and run rich and stall. I know that it is running rich by the looks of the plugs. Is this low coolant causes all this trouble?? thx ken

 

[InfiniteGSX]

My 98 GS did this when I got it, the speed sensor was unhooked. Didn't know it would effect the car this way... But noticed afterwards that the ecu would actually keep the car idleing high between gear shifts so it doesn't stall, even if you were to press the clutch or take it out of gear and the car moving, it will stay above idle rpm... until you stop the car, when it will finally drop.

 

[Kevin TSI]

Any help on this would be great.

 

[steve]

Test the IPS, VSS, ISC, and make sure that the ECU is also undamaged.
The ECU used the ISC to emulate a dashpot to keep the engine from stalling when you close the throttle and the car is moving.

Steve

 

[1slo1g]

What about a bad tune on the SAFC2? Just thought that could be it also.Good Luck

 

[Talesin]

1) Rear O2 on a 2G wouldn't affect drivability, it's just there to throw a code if your cat goes bad. Only fuel adjustments come from the front O2.

2) Refill your coolant overflow bottle, or check to make sure the sensor wire hasn't fallen off the bottom. If it has water and the wire is good and connected, you may have to clean it out as sometimes they will get 'gunked up' and stick after so many years.

3) If you have a check engine light, borrow a logger and pull the trouble codes (DTCs) or have the ECU flash out the DTCs... I believe there's an article on VFAQ or 1000AAQ about how to make it flash them out.

4) Set your base idle and timing (750+/-50 and 5 BTDC), grounding the proper connectors before you do each (so the ECU wil go hands-off). If those aren't set right, the car can have stalling problems.

5) A vacuum leak IS also a boost leak, but not neccessarily vice-versa. A vacuum leak ONLY happens on the manifold side of the throttle body... so the TB gasket to the manifold, manifold gasket to the head, maybe a disconnected or torn vacuum line, the manifold might not be torqued down fully, the EGR valve might not be bolted down tight (or stuck open) or any other of a number of potential leak locations. Take a can of carb cleaner and spray it at each of the suspected locations in turn. If the idle rises when you spray one, boom, vacuum leak. If you haven't replaced your vacuum lines, it would probably be a good idea to do so.. just remember to do them ONE AT A TIME, as figuring out the vac diagram and getting everything routed correctly can be a real pain in the ass.

You can TRY resetting the ECU, but that's unlikely to fix anything (other than clearing the CEL until the problem reoccurs). In the cabin fusebox (by your left leg while seated) pull the bottom-rightmost fuse. Your dome lights will go off, and you'll lose all your radio settings at this point. Wait two minutes (to be sure, I've gotten a successful reset waiting only 30 seconds) then plug the fuse back in. ECU has been reset, and no need to pull the battery cable off. Which is a lot harder to do than just yanking and replacing a fuse.
Make sure your idle sensor switch is connected too. It's on the throttle body.


That said, mine does a similar stalling behaviour but only when it first starts driving, no matter how long I let it warm up. Usually reverse and then braking after pulling out of my driveway is enough to stall the engine. Which is a little embarassing. Fairly sure it's a vac leak though, and also pretty sure I know right where it is in my case. Backing into my driveway has solved the issue until I can be arsed to fix the source.

 

[snafer100]

well i pulled out my haynes manual real quick today and checked my ISC motor. Just checking resistance, i went from pin's 2-1 and 2-3 and got 48 ohms resistance and from pins 5-4 and 5-6 and got 48ish again on them. It states in the book i should be reading 28-33 ohms. I did not have a 6 volt battery to actually test the movement though. What yall think???, I dont have another laying around to test.... VSS??? what is that? Biss?? also im throwing a check engine light knock sensor, when i reset the ecu it comes back without taking it over 2k in neutral. Im thinking its coming because of the stumbling of the engine as it dies. It is a new sensor. Any thought would help
thx ken

 

[steve]

I seen in another post somone stating that with the low coolant light it will think the car is always cold?

There's no truth in that. The ECU doesn't have an input for low coolant, only for the ECT sensor in the thermostat housing itself.

VSS = Vehicle Speed Sensor.

As you know your ISC coil measurements are high even for a black new style ISC and it's still possible that the ECU ISC circuits are damaged. I'm still seeing 25%+ of the ECUs that show up on my doorstep with ISC problems from capacitor leakage. Many with replacement caps installed but nothing done to fix the problem.

 

[x3whlmotion240]

u got ## bov opend? or reclirulated?

 

[Locke]

u got ## bov opend? or reclirulated?

Covered that.

BOV is recirculated.

 

[CONTROL TWO]

gotta be a leak

either from the BOV to the turbo inlet or in your "homemade ic piping"

boost leak test the hell out of it.

if it's not that, gauranteed it's your timing that is off

 

[Talesin]

Again, covered that. And it appears to be a vacuum leak, so it's not in the IC piping or stock CBV (unless he has a pipe completely disconnected or something).

Extra question that I forgot to ask before. When it's fluctuating between 16-20in/Hg, is it idle surging? I'd assume so.

 

[snafer100]

idling is not surging, i drive and push clutch in and it stalls if i dont give it gas, also does this in neutral (but not always), i had just recently had the ecu sent out to have the dsmchip installed and they also replaced some leaky capacitors while they were at it (i believe you may have done mine Steve ). tomorrow imma search more for a ISC motor sitting around and test that and see what i come with.. If i do have a vacuum leak its not a major one, but i will check again. It was sealed up tight cept for a tad bit air coming from the biss screw and my afpr adjustment screw, that was pumped up to 30 psi. im reading 15 hg vacuum(i dont think thats bad with having 101 cams in it??????). Recircluated BoV btw. I got the coolant light FIXED, i must have had a air pocket somewhere in the engine but it is good now.
Any thoughts on this knock sensor CEL? I reset the ECU and It stays off for a bit and comes right back on without driving it. My opinion is the stalling is setting it off.
Also imma check the base timing again.

 

[Talesin]

Coolant light comes on when the plastic coolant reservoir bottle is out of water. There's a sensor at the bottom. Only reason that light comes on. Nothing to do with the actual closed, pressurized coolant system at all, as far as I can find in the FSM.

 

[steve]

i had just recently had the ECU sent out to have the dsmchip installed and they also replaced some leaky capacitors while they were at it (i believe you may have done mine Steve ).

Any thoughts on this knock sensor CEL?
I reset the ECU and It stays off for a bit and comes right back on without driving it.

If I work on it I'm sure that the ISC circuits would have been tested but I don't recognise your userid. PM me with your real name.

Getting a knock sensor CEL is pretty rare, and from what little data I have, is likely caused by a disconnected or really dead sensor. I'd double check the reading, using a different method than the last time to eliminate the chance of bad datalogging software or miscounting the codes.

 

[snafer100]

i didnt have time to do much today but i double checked the CEL on a analog multimeter and read 3 long sweeps and 1 short (31) also i went to the S-AFC settings in the knock sum under idle its from like between 60-90ish. Im not thinking this is knock count is it?? thx ken

 

[TearsForTalon]

Are you venting to atmosphere? That could be it. Or you might have a vaccum l

 

[Talesin]

Are you venting to atmosphere? That could be it. Or you might have a vaccum l

Please actually READ threads before replying to them. That has been covered.