[macaw2o]

I can't seem to figure this one out, got my heagasket changed, threw in a new MAF while I was at it, as well as all new vacuum lines. Now the car seems to die when I depress the clutch or throw it in neutral. Feeding it throttle seems to keep it alive for the most part but I would like to figure out what is causing this. At first I thought the CPS was suspect but I only unplugged it when doing the head job, who knows that might have been enough to break it. I am looking for some words of advice if anyone has anything to offer.

 

[CarpeCyprinidae]

Check you have the vacuum lines all going to the right place. They get very stall-y if the lines are plumbed in wrong or the one-way valves are reversed.

 

[macaw2o]

Check you have the vacuum lines all going to the right place. They get very stall-y if the lines are plumbed in wrong or the one-way valves are reversed.

I just went out and double checked, everything is going to the right places, I used propane to search for a leak and came up with nothing. It is idling pretty rough and it has a brand new Direct Ignition Cassette. I double checked all my plugs going all over and everything is tight and going where it needs to, the car isn't throwing me any codes either.

 

[jvanabra]

Are you sure cam timing is correct? What you describe primarily sounds like a vacuum leak, but if you're sure there isn't one I would suspect cam timing.

 

[macaw2o]

Are you sure cam timing is correct? What you describe primarily sounds like a vacuum leak, but if you're sure there isn't one I would suspect cam timing.

Cam timing is all in order, it seems like it must be a vacuum leak from somewhere but the fact is I cannot seem to track it down to wherever it is coming from if there is one.

 

[BobSaabit]

Brake lines can leak.

 

[Mort]

Having recently done some vacuum lines - there is a sensor plug near the fire wall at the rear - That I had to unplug to get get to the 'T' section in the lines. I missed that plug sensor - however it gave me a P16... something code. But you said it wasn't giving you any codes?
Brake booster vacuum pipe not in?
Plug near MAF at the back of the air filter housing?

 

[macaw2o]

Having recently done some vacuum lines - there is a sensor plug near the fire wall at the rear - That I had to unplug to get get to the 'T' section in the lines. I missed that plug sensor - however it gave me a P16... something code. But you said it wasn't giving you any codes?
Brake booster vacuum pipe not in?
Plug near MAF at the back of the air filter housing?

Is that sensor plug above the brake booster where the vacuum lines from the boost pressure control valve and intake run to? i double checked that and it is plugged in all those vacuum lines are going to the correct areas. The brake booster vacuum pipe is in as well. I unpluged the brand new MAF and same issue, it actually ran so rough it sputtered out and died on me. under acceleration on the road the car is fine, only when going into neutral or depressing the clutch does the car die. At idle the car does sputter and run rough, with a blip of the throttle it revs very clean and nicely but when it comes back to idle it sputters very hard and catches itself and just idles rough. i cannot seem to find a vacuum leak if there is one with anything i try.

 

[jvanabra]

There is also the MAP sensor on the intake manifold.

The thing is, that virtually every sensor under the hood will trigger a CEL if it's missing. The primary exception to that is the CKP sensor, maybe the BCS sensor. Virtually verything else - IAT, MAP, MAF, etc. will throw an instant CEL for "out of range" if it's missing. That's why cam timing or vacuum leak are likely culprits - because they are mechanical elements the ECM can't see.

I'm just throwing stuff out, but you did have the head checked for flatness, you did use a new head gasket and new bolts, and you did follow the head bolt torque procedure properly right? You're sure you've got good compression?

 

[BobSaabit]

Did you test the check valve in the PCV line? Also make sure the fuel regulator vac line is OK (short one down by the manifold). Diverter valve (bloe off) doesn't leak?

 

[BobSaabit]

Couple other thoughts... is the DIC a SEM? Not Chinese? Are the plugs new and do you have an alternate set to try?

 

[macaw2o]

Couple other thoughts... is the DIC a SEM? Not Chinese? Are the plugs new and do you have an alternate set to try?

I'm trying new plugs tomorrow, the DIC is brand new Genuine Saab. I'm going to a pick a part in the next couple days to pull a new PCV check valve and vac lines off a convertible 93 to have spares. The thing is the car was perfect besides the head gasket and after I changed it, now I am having this issue. I've double checked my timing and all is well in that neck of the woods, my thinking now is that my plugs may have been damaged with handling? That and at the end of the day they are 20k mile plugs.

 

[BobSaabit]

Platinum plugs would normally go about 50K. Copper are good for 10-12K. Only $2.50 for BCPR6/7ES copper at the local stores... swap in some, gapped to .9mm. Either it fixes it or eliminates that as a possibility. Of course, damage can happen taking them in/out.

 

[macaw2o]

I put in the overpriced platinum NGK plugs and still the same issue. I prodded around with propane again and came up with nothing again, I am quickly running out of ideas the only other thing I can think is the DIC got damaged some how during the headgasket repair which is odd because I put it in the back of the car as soon as I took it off and only touched it when it was time to put it back on and stored it in its upright position.

 

[jvanabra]

Your symptoms don't really match with an ignition problem, they match with a mixture problem. If you have a spare it's certainly worth trying, but I wouldn't expect results. Have you tried a compression test? An intake pressure test?

 

[macaw2o]

Your symptoms don't really match with an ignition problem, they match with a mixture problem. If you have a spare it's certainly worth trying, but I wouldn't expect results. Have you tried a compression test? An intake pressure test?

No, I haven't tried either yet as I don't have a compression tester yet, I also am unaware of exactly how to test the intake pressure.

 

[Boxer-Moto]

Do T7 cars have a similar EVAP purge valve system as the T5 cars? It sounds a lot like the behavior my car (T5) exhibited when the valve failed. It's been a BUNCH of years, but I recall disconnecting the vacuum hose to the valve (and plugging the throttle body side) as verification. IIRC, it would stall at idle with the valve connected, but no CEL...with the hose disconnected, it would NOT stall, but the CEL would come on...

Again, I don't know enough about the T7 cars to know if they even have a similar system, or not

 

[Mimmi]

Bad by-pass valve.

 

[macaw2o]

Do T7 cars have a similar EVAP purge valve system as the T5 cars? It sounds a lot like the behavior my car (T5) exhibited when the valve failed. It's been a BUNCH of years, but I recall disconnecting the vacuum hose to the valve (and plugging the throttle body side) as verification. IIRC, it would stall at idle with the valve connected, but no CEL...with the hose disconnected, it would NOT stall, but the CEL would come on...

Again, I don't know enough about the T7 cars to know if they even have a similar system, or not

I couldn't tell you I am not familiar enough either, maybe someone with some more experience with both might be able to chime in.

 

[macaw2o]

Bad by-pass valve.

Any way to test it?