Hot Rod Forum banner
1 - 19 of 19 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter · #1 ·
Well i'm back, ok this is the situation now. We are getting alot of poping out the exhaust. It's dying @ 2500rpm's and we are not running the msd anymore. We bought a new carb it's a Holley 850 double pump, just curious what jets would be best for this engine., and how much fuel pressure. Right now we are running 83 in the front and 80's in the rear with 8psi of fuel pressure. It's starts and idols perfect, but as soon as we get in it after about 2500rpms it just pops and dies. Once again we are going crazy with this. Please any help would be greatly appreciated. Thanks again.
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #7 ·
Really we havent changed anything, except we went from HEI to the MSD, changed the jet's now we are running 83's in the front and 80's in the rear. With the timing light we are running about 16 degrees advanced, re-gaped all the plugs from 35 to 45 and it's still cutting out at around 3000rmp's and if we are able to get pass that it usually dies on deceleration, popping out of the exhaust. But it starts right back up after it dies, idols fine just when we get on it, it dies. We raised the fuel pressure to 8psi, and no change. We are running a holly blue electric pump with a max of 14 psi and it is located in the trunk, with steal braided lines. The valves are set at 0 lash plus half a turn. We are running a torquer 2 single plane intake with a 1in spacer. Dart Pro 1 angle plugged heads. The engine is at 11:5:1 compression with forged flat top pistons.
 

·
Registered
Joined
·
904 Posts
Do you still have the HEI dist. with a MSD incap coil , you may have a bad pickup,or did you change to a MSD dist? has the coil been changed? I don't think you have much left? You may need to start over and recheck?
 

·
Pure American Muscle
Joined
·
684 Posts
Yes I hope you changed your coil. MSD suggests that you always use it's 'Blaster' or 'Blaster 2' coil with it's ing. systems. If you get a new coil make sure it is what is suggested by MSD it may be something special to do with the coil and the way the system runs and the older coil is not up to par for it.


I see you replaced the MSD ing with the HEI.
Does the engine run smooth and good at below the 3000RPM mark? This seems like it is a very strange problem. Hope it gets worked out here.

Chris
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #11 ·
with the hei it ran the same as now with the MSD, idoles fine, runs well up too about 3000 rpms. But it will open up to about 6K rpms on occasion but on the way down it always dies. But once we clear it out it seems to run better, but it always dies on the way down. It just wont run after getting over a certain rpm.
 

·
Shop Owner And Troll Hunter
Joined
·
2,643 Posts
Are you getting any black smoke? The jets sound a little big. Maybe should be high 60s low 70s #. Fuel pressure should be
4 1/2-5 lb. The fuel pump should be below the tank. Plugs gaped at 35. Last of all recheck the floats they could be way to low.

Troy
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #13 ·
We are not getting any black smoke, a stock fuel pump is putting out 6psi we are running a holly blue fuel pump. We tried running 70's in the carb and it would get over 1500rpm's with out acting like it wanted to die. In the MSD book it says to gap the plugs from 40-50 with all compressions from 10:5:1-13:0:1 we are running 11:5:1. Checked the floats and they are set to holley specs. The holley 850 that we purchased came with 80's in the front and 80's in the rear from factory. What could cause this engine to die on deceleration. That is the only time that dies.
 

·
Pure American Muscle
Joined
·
684 Posts
Do you have a fuel pressure regulator. Just a thought but without it that could cause a problem with the delivery of fuel I may be way off here but it's always good to have one to monitor fuel pressure and such in what sounds like a pretty warm engine.

Chris
 

·
Shop Owner And Troll Hunter
Joined
·
2,643 Posts
I tryed a pump in the trunk once, didn't work to well as the pump is a pusher and depends on gravety to get it's supply. Just a thought.

Troy
 

·
Registered
Joined
·
904 Posts
Are the heads and valves New? never run? I had a problem with a set of Dart heads that the SS exhaust valves were to tight in the the head and they would stick open just a bit till i removed the oil seals to let oil in and got some run time on the engine, in the driveway! That was very strange to track down. it would idle fine till till you rev-ed it and would start missing and try to stall back to idle , unless you feathered the throttle , this happed only after the motor was heated up to run temperature.
 

·
Registered
Joined
·
74 Posts
strokerchevyII said:
The valves are set at 0 lash plus half a turn. We are running a torquer 2 single plane intake with a 1in spacer. [/B]
Just a quick thought, maybe back off your lash adjustment a 1/4 turn. I had one after a rebuild that would do a similar problem. Readjusted and it cleared. Easy check to do.

One other thought do you need to run the spacer? Just thinking travel time on the mix getting there.

I know this may sound silly, but you never know. Cars are just like the ladies.... sometimes you have to do things that make absolutely no sense to us guys.

Pappy
 

·
Come Home Safe Soldier
Joined
·
846 Posts
I had a problem similar to that,car ran fine then it would just up and die.I run a 6AL box and pro-billet MSD distributor.It turned out to be a bad connection in the eyelet that was going to the ground terminal of my Blaster 2 coil.When the engine idled it did not twist,when it throttled up,was just enough to move the wire in the eyelet and would lose current.What is your complete ignition setup?
 
1 - 19 of 19 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top