Help needed

-
Ozcuda

Ozcuda

gotta love a MOPAR
Joined
Feb 24, 2006
Messages
248
Reaction score
2
Location
Australia
Hi Guy's,

It's been awhile since I've been able to get the old bus out. Anyway last week I did manage to & I seem to have a stutter it's hard to explain but I'll try.

I do my burnout no worries stage & hit it out the hole sweet then I get a feeling like it's starving for fuel then less then a second later it's off again. I never acts up like this on the dyno

I'm sure fuel isn't the issue as I have 150gal pump with 1/2id fuel line all the way. I'm running 8psi at the reg it seems to be stable on the dyno.

I am thinking it is my ignition I run a Accel electronic dizzy with super stock coil 10mm leads. it has never given me any trouble before.

Anyway here is what I am looking at we have slowly been removing mechanical driven parts such as water pump, fuel pump engine fan all being replaced with electric items.

The car is still fitted with the original 35 AMP alternator set up here's the 100 dollar question is the alternator able to supply enough power to run all of it.

If not what alternator should I be looking at getting ???
If I need a bigger alternator will my wiring be able to handle the extra load ???

Thanks Oz
 
I dont think its electrical because its only for a moment. Low voltage would probably show up first at the big end. I would look at the carb. Dirt or a gummed up circuit. Maybe fuel slosh. 8psi is pushing it for pressure. I prefer 6 myself.
 
As you said..you haven,t had the car out in awhile.I would check fuel filter for any debris/dirt from sitting,then check carb bowls.Good luck.
 
pettybludart said:
As you said..you haven,t had the car out in awhile.I would check fuel filter for any debris/dirt from sitting,then check carb bowls.Good luck.
Click to expand...

Hi, Fresh fuel new carb I am checking the filters

Thanks Oz
 
hangn0ut said:
I dont think its electrical because its only for a moment. Low voltage would probably show up first at the big end. I would look at the carb. Dirt or a gummed up circuit. Maybe fuel slosh. 8psi is pushing it for pressure. I prefer 6 myself.
Click to expand...

We started the pressure at 6psi & turned it up thinking it might have been the problem.
The problem is at high RPM.
It's a new carb with slosh tube & I have a sump in the fuel tank facing rearward so fuel pick up shouldn't be a problem

thanks Oz
 
Do you have a fuel pressure gauge you can see from your seat? I have seen this before and the fuel reg. plunger would intermittently hang open and almost always happen right after the initial hit of the line. Just something to check ours was checked a few times before we where lucky it finally happened in the pits.
 
So is it a new carb or one that was on the car last season? If its last years carb go through it
If new dial it in.
 
bsad67 said:
Do you have a fuel pressure gauge you can see from your seat? I have seen this before and the fuel reg. plunger would intermittently hang open and almost always happen right after the initial hit of the line. Just something to check ours was checked a few times before we where lucky it finally happened in the pits.
Click to expand...

No visual pressure gauge yet but we watched it on the dyno runs & no pressure drop. It seems to be after I shift into 2nd gear or in top gear not a problem at launch.

Thanks Oz
 
hangn0ut said:
So is it a new carb or one that was on the car last season? If its last years carb go through it
If new dial it in.
Click to expand...

Yeah new carb but was fitted at the tune shop & set up on the dyno was running perfect when I left.....A week later go to the track......I haven't touched a thing & it's not right.

My tuner thought it was fuel delivery...But after a little fiddling we think it's more that the 35Amp Alternator hasn't got enough output & the ignition is braking down.

I am more interested in what alternators & ignitions everybody is using to compare.
As I said I have electric fuel pump, electric water pump & fans pulling power I don't think the alternator is coping.

Thanks Oz
 
Hi Oz. I agree you may be taxing that alt. some, but did it run ok in this same configuration before? How about the battery? Meaning are you starting with a full/deep charge. If it's weakened some while sitting, could that be something to look into. I know a few guys years back that ran with no alt, just a high capacity (2) battery system.


P.S. one other thought, how long was it parked? I don't know if you have a solid lifter valve train, but some of the springs might tend to weaken being open for a long time?
 
just for trouble shooting, since electric fans have a high draw, right before you launch turn them off and then see how it goes. if it still occurs but acts a little better, next time try with fans and water pump off. Fuel pump could be dropping pressure because of voltage drop with high draw electrics.
 
Why would you have your electric fan on while making a pass. I only turn mine own for about 4-5 minutes after I get back to the pit spot.
 
OldmanRick said:
Hi Oz. I agree you may be taxing that alt. some, but did it run ok in this same configuration before? How about the battery? Meaning are you starting with a full/deep charge. If it's weakened some while sitting, could that be something to look into. I know a few guys years back that ran with no alt, just a high capacity (2) battery system.


P.S. one other thought, how long was it parked? I don't know if you have a solid lifter valve train, but some of the springs might tend to weaken being open for a long time?
Click to expand...

it has been little changes a long the way it's run a best of 11.29sec @118mph.

I have 3 batteries & to keep them maintained I swap them around in my work truck.

As for the Valve train it was checked a few months ago & all good.
 
spl440 said:
just for trouble shooting, since electric fans have a high draw, right before you launch turn them off and then see how it goes. if it still occurs but acts a little better, next time try with fans and water pump off. Fuel pump could be dropping pressure because of voltage drop with high draw electrics.
Click to expand...

Yes that would be good but I run a Davis Craig system the water pump & fans run of a control unit it switches itself on & off as the engine heats up & cools down.

I was thinking of removing the control unit & just going to a switch instead.

Thanks Oz
 
D-50394 said:
Why would you have your electric fan on while making a pass. I only turn mine own for about 4-5 minutes after I get back to the pit spot.
Click to expand...

They run off a control unit I have no way of switching them on or off. I may have to fit a master switch.

Thanks Oz
 
I wired my fan and water pump drive with switches,so I can control my temps.I also swapped to a 80 amp alternator at the start of the 2015 season.I think your right that your setup is drawing too much power with that small output alternator.I would go bigger.JMO
 
pettybludart said:
I wired my fan and water pump drive with switches,so I can control my temps.I also swapped to a 80 amp alternator at the start of the 2015 season.I think your right that your setup is drawing too much power with that small output alternator.I would go bigger.JMO
Click to expand...

Petty,

Yes I will be installing a switch & removing the control unit for the fans & pump.

What is your alternator off ?

Thanks Oz
 
You must log in or register to reply here.
-

Back
Top