Hi All,
Got some questions to ask, I got a 72 240 with an L28 engine. The other day this problem suddenly occured and I'm not sure how to fix it. Here is the problem, the car seems to bog down at around 2500 rpm all the way up. I would be flooring it and it slowly climbs up the rpm range. If I keep it under that rpm range then it excellerated great until it hits that dead zone.
I tried flooring it and while in the bog range I pulled back on my choke level and it seems to help up to rpm range higher, like 3500 rpm then it repeats the bog from there on up. I thought it was my floates and adjusted those to no improvement.
I got a ZX fuel pump that I think will pump way more then what I need for these SU's. I will be installing the fuel pump to a fuel regulator (4-9psi) to a fuel pressure gauge (0-16psi). I'm planning of setting it to 4.25psi. Do you guys think this will help or damage the fuel pump by causing to much restriction?

Any help is appreciated.

 

could be overflow.... sounds more electric, as things like this doesn't just happen to the carbs unless somethings broken

change ur fuel filters also... ...

set it to 4.25 and thats good presure...


<font color=blue>76 260z</font color=blue>
The NiteRider

 

Yeah, I thought it was fuel filter and changed that to no improvement.
Will be trying this this weekend - coke can with fuel hooked directly to mechanical fuel pump. Reason, eliminating fuel lines. Possiblitity fuel line corroded and clogged.
Timming is right on or didn't change, since this just all of a sudden happend. Check to see if it was tighten down and yes it was.
Thanks,

 

I had a similar problem on a ~10 yr old truck once. It was a nasty fuel tank interior. Variety of water and tank corrosion bits had restricted fuel movement in and out of the tank. Helped a friend diagnose a similar behavior on a Scirocco engine in a Rabbit swap (don't ask), which turned out to be a crimped line. If you've done under car work lately and may have bumped the line enough to pinch it a bit, that might be an issue. At any rate, those are all nice easy things to check first before taking more trouble, if you haven't already. Good luck!
Dave

 

How did the filter look? Don't foget the filter in the carbs. Does it rev to 2500 then shift and rev to 2500 again (like electrical) or when you shift does it still bog (like float bowls are empty).
onefstz

 

Well, the filter I replaced looked clean but replaced it anyways. I did take a look under to see if any lines are crimped but didn't notice any and I just had a radiator place boil the tank so I'm pretty sure its clean in there.

It does rev to 2500 and shifts, anything under 2500 and it would excellerate like a rocket but bogs down above that with choke fully down. If I pull the choke up fully while under throttle it goes to 3500 then bogs down.

It could be electical but why would it be different when I pull the choke if it was. There is no electical connection to the choke that would tell the system to allow it to rev higher simply because choke is on. Basically, I got spark when I need it.

 

Like electical, it shift and revs fine up to 2500rpm.

The filters are removed on the entrance of fuel to float chamber.

 

Do you all think it is a float level and fuel problem when going through the gears and I pull the choke all the way up it excelerates good but just pushes the bogging up to a higher level?