Troubleshooting possible vacuum leak

[aldad138]

I have a new carb installed and starting yesterday, when leaving a stop at idle in 1st, she sputters and has no power...gets to 2000 rpm and seems "fine".  Upshifting to 2nd, a bit of sputtering and then seems OK.  Vacuum leak?  Exhaust leak?  What is the best way to trouble shoot and identify the issue?  Also, maybe not coincidental, there is black carbon deposited near the muffler on the ground, when she idles for a while.  Running to rich?

Just the newest thing keeping her OFF the road. 

Alex

[mwredit]

I would squirt carb cleaner around the intake manifold / head joint, base of the carb, vacuum hose connections, etc to try to locate the source of the leak.  When you spray around, you will notice a change in the idle speed when you get to the problem area.  Maybe verify carb float level and try a different float needle and seat.  I've found them bad right of the box before. As a last resort, reinstall the old carb if you still have it to rule out a problem with the new carb.

I just acquired a practically rust free '77 HPE two weeks ago that needs reworking of the mechanicals.  The body is straight with no dents, but needs a new paint job.  Need to replace the seals on the engine and upper gaskets, it seeps oil from every orifice, CV boots, A arm and stabilizer bushings and carb rebuilding.  The larger diameter vacuum hoses going to the brake booster look suspect, as I would check that on yours also. Otherwise, it's a runner.  Good luck. 

-Mike

[Neil-yaj396]

Have you fitted a brand new carb? If not it will almost certainly be dirt in the jets causing the problem. Even fully refurbished carbs are not always as clean as they should be.

Loads of threads about carb issues on here, but this is my favourite;

http://www.betaboyz.myzen.co.uk/forum/index.php?topic=649.0

[aldad138]

Thanks Neil- It is a rebuilt carb from Midwest Bayless in the USA.  That said, I have been in there a lot and would not discount the possibility of dirt getting in there.  I will check that thread and see the commonalities so I can start ticking things off the list.

Alex

[aldad138]

Thanks Mike and good luck with the HPE.  The brake booster is giving me grief, and I suspect it is the vacuum check valve leaking.  I am trying to find a suitable replacement, and have been monkeying around enough that it could be lost vacuum from the manifold to the booster.  I will be ticking things off the list this weekend. 

Enjoy your build!

Alex

[mwredit]

Your welcome, Alex and thank you.  I had an HPE back 25 years ago and only had it for 6 months.  It had a lot of issues, rust in the A pillars, missing smog equipment (I live in Calif), overheating problems and a badly leaking steering rack.  I was a 20 year old kid (I'm dating myself), was wet behind the ears and over my head then, but I remember how that car drove and rode and had never forgotten it.  As I'm changing around projects currently, I decided to try to hunt down an HPE.  I found one a few weeks ago, and amazingly in better condition compared to the one I had in 1991, I bought it. Almost rust free (it was stored indoors for over 20+ years).  It even passed California smog last year!  I have a boatload of work to do on it, such as engine seals and gaskets, CV boots, carb rebuild and interior work.

-Mike

[aldad138]

Amazing how your story sounds like mine, with my 79 Strada...LOVED that 3 door hatch but for various and similar reasons parted ways 22 years ago. I owned it, in repair and disrepair from 88 to 93.   Then got a bedraggled 77 Alfetta but it had to go, as it was wrecked to the frame.  Now, back with my 79 coupe and just trying to get her reliably on the road, then will work on the resto. The 20 miles I have put on her recently, have been brilliant, then the sputter. 

Where in Cali?  I am in Oregon, but come to the Bay area every year and LA on occasion for friends and family.  Alex

[aldad138]

Petite update:  Closing off the fuel return line, since my rig has an electric fuel pump, along with new plugs and she is running 80% better.  This is great, now I have to sort out adjusting the shifter linkage.  I can't find 3rd, and keep finding 1st or if I am lucky 5th. 

Alex