327 coughs and dies during gearchange.

[UKSquarebody]

Hi all,

My 87 R10 has a 327 fitted (prior to my ownership), mated to a 700R4 (freshly rebuilt).
It has HEi dizzy, 1406 Edelbrock. Timed at 14 degrees with vac off at 750rpm.

It idles great, idles great when in gear.
But start driving, and the minute the box changes to second, the engine coughs, splutters and dies.

I cannot find a vac leak on the engine, but have seen that brake fluid is now running from between the master cylinder and servo.
New servo and master cylinder are on their way to me from the States.
Is this the likely cause of my running issue?

thanks in advance,
Keith

 

[75gmck25]

There is a large diameter vacuum hose (3/8”?) from the intake to the brake booster, so a booster failure could cause a big vacuum leak. However, I don’t know why it would be tied to the shift into second, unless it’s just a factor of more engine load at that speed.

 

[UKSquarebody]

There is a large diameter vacuum hose (3/8”?) from the intake to the brake booster, so a booster failure could cause a big vacuum leak. However, I don’t know why it would be tied to the shift into second, unless it’s just a factor of more engine load at that speed.

Yeah - that was. My reasoning, but unsure why it’s linked to gear shift - when it idles and runs great anyway.