EFI dies at stop with gear change

[chuzie]

'77 w/ 89 302HO EFI, C4, D20, 9" (4.56) and 35" tires.

I have never had a stalling issue in the past. Recently I changed my gearing to 4.56 from 3.50. Took it out a few weeks ago for the first time since the gearing change. Running through the trails, I would stall out when I came to a stop or even coasted up a whooptie doo and peaked (really slow).

It is not angle dependent and starts right back up with no issue at all.

I increased my idle from 700 to 1100 and it still stalls out. If I hit the gas just before it stalls, it will arrest the stall.

I wonder if my gearing change may have caused this issue. I need to call transtar and confirm what stall converter they sent me.

Any thoughts?

 

[blazinchuck]

i didnt realize this was a serious issue when it happened at URE. curious to see some thoughts

 

[73azbronco]

codes?

added to make 8

 

[chuzie]

No codes. Runs like a champ except when I am sitting vertically on a rock for longer than my 1 cup accumulator can support!

 

[blazinchuck]

ya know...my motor was used with 1 tons,4sp, and 4.88's and c4,3.50's and now a 5sp with 3.50's. i really cant see how a gear change would or could affect the motor. could there be something wrong with the VSS??

 

[Viperwolf1]

Clean the throttle body and the IAC.

 

[Broncobowsher]

Do you have the VSS hooked up?

 

[chuzie]

VSS is hooked up. Throttle body was just cleaned but I can check the IAC and clean it. Again, no codes (KOEO, KOER, KOEM) so all the sensors are operating within range.

 

[chuzie]

IAC is clean.

 

[Viperwolf1]

Does it run better with the MAF unplugged? Did you look for vacuum leaks?

 

[chuzie]

I will check for vac leaks tomorrow. Come to think of it, it has been dying immediately after start from time to time. That sounds like a vac issue.

 

[Viperwolf1]

Or possibly dirty MAF.

 

[chuzie]

I will take a look at the MAF, but I cleaned that sucker about two months ago.