Vacuum pressure to transmission

[Brahh]

I just recently finished a 10 month tear and build up, I ran into a bad surging idle from leaking headers, vacuum leak and a bad 02 but they were just replaced and there is absolutely no surging idle or any vacuum leak and it doesn't try to stall at every stop light or kill itself with harder brakes or etc. But one thing that it does do is a shift from park -> Drive or Reverse will make the car kill itself unless I slightly two step (~100 rpm) like I was beforehand with the surging idle after i'm in drive or reverse I have no issues whatsoever cold or warm. My mechanic buddy who is diagnosing it says there is too much vacuum pressure going to the crankcase and I should research to see if I can find a regulator or just a solution since he's as stumbled as me.


Here are the mods on the car (If it helps):

Stock 302 (.30 over)
10:1 compression (Dome)
E303
Stock E7 heads (max ported)
1.7 Crane Gold RR's
Edelbrock Performer intake
70MM Edelbrock Throttlebody
CAI
Underdrive pulleys
BBK Equal length headers
Remanufactured AODE
2800 Stall Torque converter
4.10's
NGK iridum spark plugs and NGK O2's
9MM FMS ignition wires
New alternator & Battery
EGR was deleted
SCT chip with the american muscle canned tunes for the above mods


If anyone can give some advice or even some guidance on what should be tested, would be much appreciated!


Best regards!

 

[toyman]

. My mechanic buddy who is diagnosing it says there is too much vacuum pressure going to the crankcase and I should research to see if I can find a regulator or just a solution since he's as stumbled as me.

Okay, now you have me stumped. What are you saying? Vacuum pressure to the transmission? Vacuum pressure to the crankcase? Your mechanic buddy is out to lunch. There is no vacuum control/regulator to the transmission. You have an AODE. It is controlled by the PCM. If I've interpreted you correctly the car will sometimes stall when shifting from Park into Drive or reverse, is that what the issue is? If it is, the problem is most likely a failed or failing IAC valve.

 

[Brahh]

Yeah sorry, that's what I ment. Whenever I shift from park to drive or reverse it stalls always. I replaced the IAC with the borg warner one from pepboys and it made no difference :tard: if you have any other ideas they'd be greatly appreciated!

Also I forgot to note but it's timed at 8* on 10:1 compression when its timed to 10* it knocks on 91 octane when it was tuned for that, maybe it was the canned tune?

 

[toyman]

I'm not big on "off the shelf" tunes. Every combo is a little different. With the e cam and the EGR delete you might need to have the car tuned. While not related to the issue I would also go back to copper core plugs.

 

[modo]

what rpm is the car idling at while in park and also in drive when the motor is at temperature?

 

[Brahh]

it idles steady at 1050 in park and 750 in drive, just when I shift from park to drive or to reverse it goes from 1050 to like 500 and dies unless a tad bit of pedal is added then it'll stay alive and from there on it's completely fine.




Well, it was tuned for my mods just more on a best guess basis but I figured that would be enough to have the car driveable in all conditions until a full dyno tune :thumbsup: and I would assume they have and will recieve a ton of requests for the e cam tuned in. Also, would it make any difference going back to copper as you suggested? I read iridium was fine just not platinum, they were pretty pricey so I would rather just run them until they give out I mean unless they're a problem.

 

[modo]

well 750 might not be enough... every car is different. did you set the idle correctly?

another person will make this easier. start with the motor cold. start it up and let it idle for a couple minutes. shut it off and disconnect the iac. start it up and set the idle with the set screw while in drive (parking brake on) and get the idle to 750 or 800. shut it off and reconnect the iac. see if that helps... if it does not then pull the battery for a couple minutes and when you reconnect it let the car idle with all accessories on for a couple minutes.

if that doesn't work then you should test the iac motor, clean it and or replace it

in the tune there is a idle rpm which the iac will attempt to keep but it also relies on the set screw being set properly. since your tb is not stock i would start there