Rebuilt 289 engine, stalls out if rpm is normal for engine, erradic engine with the slightest thrott

5

Asked by Jul 16, 2009 at 02:10 PM about the 1966 Ford Mustang Base

Question type: Maintenance & Repair

I just rebuilt my 289. stock crank, mild comp cam, 10:1 pistons, edlebrock perf289 manifold, 600 holley 4bbl, stock distributor.  In order to get it running reasonable, the timing had to be set at 30deg off TDC.  Now, in order to put it in drive without stalling (c4 tranny), the RPM has to be much higher than normal.  The idle is rough (cam is supposed to be a smooth idle), and when it's in drive, without touching the throttle, the engine occillates it's RPM--sometimes significantly.  When I apply a little throttle, the engine is very quick to respond, and maintaining very little throttle causes the engine to ocsillate it's RPM--more throttle eliminates this.  Carb has been rebuilt and tuned (so they say).  They also say that the vacuum is lower than normal, but they expected that with a performance engine.
Any ideas?

3 Answers

7,375

timing and carb are off. why did the timing need to be 30 degrees of TDC? was it required with the cam? im guessing something is up with the carb. whomever rebuilt and tuned it needs to redo it. sounds like it was done wrong.

175

This is just a guess but is it possible that when they reaasembled your engine they didn't align the timing marks on the crank and the cam properly. Unless it's a radical cam, the vacuum shouldn't drop very much and the idle shouldn't suffer either. I have a mild cam in my '67 289 and it has a smooth idle at 600rpm in drive, about 850-900 when in park.

5

The timing of the Camshaft is my first thought. We're going to look into the timing of #1 valves with respect to TDC. I'll re-check the vacuum and see where the needle dances.

Your Answer

Add photo

Related Questions

Mustang

Looking for a Used Mustang in your area?

CarGurus has 44,787 nationwide Mustang listings starting at $1,500.

ZIP:

Search Ford Mustang Questions

Ford Mustang Experts

#1 Tom Demyan
Tom Demyan
Reputation 4,500
#2 Bob Beaman
Bob Beaman
Reputation 1,240
#3 COMETGUY61
COMETGUY61
Reputation 1,090
View All

Related Models For Sale

Used Chevrolet Camaro
355 Great Deals out of 31,416 listings starting at $2,400
Used Dodge Charger
522 Great Deals out of 28,799 listings starting at $2,500
Used Chevrolet Corvette
220 Great Deals out of 22,191 listings starting at $3,850

Used Cars For Sale

2017 Ford Mustang For Sale
74 Great Deals out of 23,003 listings starting at $18,998
2016 Ford Mustang For Sale
194 Great Deals out of 4,344 listings starting at $15,391
2015 Ford Mustang For Sale
78 Great Deals out of 3,282 listings starting at $13,999
2014 Ford Mustang For Sale
66 Great Deals out of 3,098 listings starting at $9,000

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.