A Cars forum. AutoBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AutoBanter forum » Auto newsgroups » Antique cars
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Can anyone solve this problem??



 
 
Thread Tools Display Modes
  #1  
Old November 30th 04, 09:47 PM
Joe6pak
external usenet poster
 
Posts: n/a
Default Can anyone solve this problem??

My 327 Chevy engine was running well, but I noticed that the fuel pump had a
small leak, so I installed a new fuel pump. After installing the fuel pump
and cranking her up, the motor was shuddering like crazy, but then smoothed
out, however the shuddering resumed as soon as I put it in a foward gear. I
reinstalled the old pump but the engine is still shuddering. The wierd
thing about this problem is that the engine will idle fine and will move in
reverse gear with no problem, but as soon as I put it in a foward gear, it
shudders and stumbles wildly. If I put it back in neutral it idles fine, and
I can rev the engine way up without any problem.

So far I have installed a carb kit (Edelbrock 600) and installed new spark
plugs but still have the exact same stumbling and stalling problem when
foward gear is engaged. This thing has me mystified and I really would
appreciate any ideas anyone might have as to the possible source of this
problem. (Tranny is a 350TH).

Thanks in advance for any advice.


Ads
  #2  
Old November 30th 04, 11:23 PM
sdlomi2
external usenet poster
 
Posts: n/a
Default


"Joe6pak" > wrote in message
news:715rd.17$Yp.10@lakeread01...
> My 327 Chevy engine was running well, but I noticed that the fuel pump had

a
> small leak, so I installed a new fuel pump. After installing the fuel

pump
> and cranking her up, the motor was shuddering like crazy, but then

smoothed
> out, however the shuddering resumed as soon as I put it in a foward gear.

I
> reinstalled the old pump but the engine is still shuddering. The wierd
> thing about this problem is that the engine will idle fine and will move

in
> reverse gear with no problem, but as soon as I put it in a foward gear, it
> shudders and stumbles wildly. If I put it back in neutral it idles fine,

and
> I can rev the engine way up without any problem.
>
> So far I have installed a carb kit (Edelbrock 600) and installed new spark
> plugs but still have the exact same stumbling and stalling problem when
> foward gear is engaged. This thing has me mystified and I really would
> appreciate any ideas anyone might have as to the possible source of this
> problem. (Tranny is a 350TH).
>
> Thanks in advance for any advice.
>
>

The cheapest/simplest thing that comes to mind and just a wild guess, as
learned from past work on hot rods: Check the transmission-to-engine bolts.
I've seen them work loose and cause the symptoms you mention. It does not
sound like it has anything to do with the fuel pump, but just a coincidence
it happened right after you changed it. HTH, s


  #3  
Old November 30th 04, 11:50 PM
scott and barb
external usenet poster
 
Posts: n/a
Default

Sounds also like a bad fuel pump.Will idle (maybe) until you try to drive
it.Had a maddening problem like this years ago on a chevy 6.
"sdlomi2" > wrote in message
...
>
> "Joe6pak" > wrote in message
> news:715rd.17$Yp.10@lakeread01...
> > My 327 Chevy engine was running well, but I noticed that the fuel pump

had
> a
> > small leak, so I installed a new fuel pump. After installing the fuel

> pump
> > and cranking her up, the motor was shuddering like crazy, but then

> smoothed
> > out, however the shuddering resumed as soon as I put it in a foward

gear.
> I
> > reinstalled the old pump but the engine is still shuddering. The wierd
> > thing about this problem is that the engine will idle fine and will move

> in
> > reverse gear with no problem, but as soon as I put it in a foward gear,

it
> > shudders and stumbles wildly. If I put it back in neutral it idles fine,

> and
> > I can rev the engine way up without any problem.
> >
> > So far I have installed a carb kit (Edelbrock 600) and installed new

spark
> > plugs but still have the exact same stumbling and stalling problem when
> > foward gear is engaged. This thing has me mystified and I really would
> > appreciate any ideas anyone might have as to the possible source of this
> > problem. (Tranny is a 350TH).
> >
> > Thanks in advance for any advice.
> >
> >

> The cheapest/simplest thing that comes to mind and just a wild guess,

as
> learned from past work on hot rods: Check the transmission-to-engine

bolts.
> I've seen them work loose and cause the symptoms you mention. It does not
> sound like it has anything to do with the fuel pump, but just a

coincidence
> it happened right after you changed it. HTH, s
>
>



  #4  
Old November 30th 04, 11:56 PM
Anthony
external usenet poster
 
Posts: n/a
Default

"Joe6pak" > wrote in news:715rd.17$Yp.10@lakeread01:

> My 327 Chevy engine was running well, but I noticed that the fuel pump
> had a small leak, so I installed a new fuel pump. After installing
> the fuel pump and cranking her up, the motor was shuddering like
> crazy, but then smoothed out, however the shuddering resumed as soon
> as I put it in a foward gear. I reinstalled the old pump but the
> engine is still shuddering. The wierd thing about this problem is
> that the engine will idle fine and will move in reverse gear with no
> problem, but as soon as I put it in a foward gear, it shudders and
> stumbles wildly. If I put it back in neutral it idles fine, and I can
> rev the engine way up without any problem.
>
> So far I have installed a carb kit (Edelbrock 600) and installed new
> spark plugs but still have the exact same stumbling and stalling
> problem when foward gear is engaged. This thing has me mystified and I
> really would appreciate any ideas anyone might have as to the possible
> source of this problem. (Tranny is a 350TH).
>
> Thanks in advance for any advice.
>
>



Hrm...got any motor mounts loose/broken? (moving the motor over far
enough to uncover a jet maybe?)
Anything else you took loose to change the fuel pump?
Any hoses coming to the fuel pump getting pinched/kinked when the motor
rotates over from the normal give in the mounts?


--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email
  #5  
Old December 1st 04, 05:31 AM
boB
external usenet poster
 
Posts: n/a
Default

Joe6pak wrote:
> My 327 Chevy engine was running well, but I noticed that the fuel pump had a
> small leak, so I installed a new fuel pump. After installing the fuel pump
> and cranking her up, the motor was shuddering like crazy, but then smoothed
> out, however the shuddering resumed as soon as I put it in a foward gear. I
> reinstalled the old pump but the engine is still shuddering. The wierd
> thing about this problem is that the engine will idle fine and will move in
> reverse gear with no problem, but as soon as I put it in a foward gear, it
> shudders and stumbles wildly. If I put it back in neutral it idles fine, and
> I can rev the engine way up without any problem.
>
> So far I have installed a carb kit (Edelbrock 600) and installed new spark
> plugs but still have the exact same stumbling and stalling problem when
> foward gear is engaged. This thing has me mystified and I really would
> appreciate any ideas anyone might have as to the possible source of this
> problem. (Tranny is a 350TH).
>
> Thanks in advance for any advice.
>
>

First, check fuel pressure at the carb. Then do a quick flow
check. Open the float bowls and take a look around. There may have
been some debris in the new pump, and now it's stuck in the small carb
passages, or your in line filter is clogged up with it.

--
..boB
1997 HD FXDWG - Turbocharged!
2001 Dodge Dakota QC 5.9/4x4/3.92
1983 GMC Jimmy - Mountain Beater
1966 Mustang Coupe - Daily Driver
1966 FFR Cobra - Ongoing project

  #6  
Old December 1st 04, 06:57 AM
Eugene Blanchard
external usenet poster
 
Posts: n/a
Default

Are the fuel pump hoses pinched. Could of pinched when removng the old pump
or when installing the new pump. Putting the old pump back on would cause
the same systems. Since both pumps do the same thing.

How about the fuel filter at the carb? I always put an inline fuel filter
before the pump to catch debris from the gas tank. At the carb there is
usually a little tiny fuel filter that when it clogs, allows idle but the
engine runs out of gas above idle.

Joe6pak wrote:

> My 327 Chevy engine was running well, but I noticed that the fuel pump had
> a
> small leak, so I installed a new fuel pump. After installing the fuel
> pump and cranking her up, the motor was shuddering like crazy, but then
> smoothed out, however the shuddering resumed as soon as I put it in a
> foward gear. I
> reinstalled the old pump but the engine is still shuddering. The wierd
> thing about this problem is that the engine will idle fine and will move
> in reverse gear with no problem, but as soon as I put it in a foward gear,
> it shudders and stumbles wildly. If I put it back in neutral it idles
> fine, and I can rev the engine way up without any problem.
>
> So far I have installed a carb kit (Edelbrock 600) and installed new spark
> plugs but still have the exact same stumbling and stalling problem when
> foward gear is engaged. This thing has me mystified and I really would
> appreciate any ideas anyone might have as to the possible source of this
> problem. (Tranny is a 350TH).
>
> Thanks in advance for any advice.


  #7  
Old December 1st 04, 06:26 PM
Tim
external usenet poster
 
Posts: n/a
Default

Hi,
I had the same symptoms with an Edelbrock carb. I finally determined that
the fuel pressure was too high causing the car to idle really rough, stall
with hard stops and hard turns. The float valves just could not hold the
pressure and the carb would flood.

Even Edelbrock's so called street pump was too strong at 8 lbs/sq in
pressure. I finally installed a fuel pressure regulator.

Check that your fuel pressure is below 5 lbs/sq in. I set mine at 3.5 lbs/sq
in and that is for my 350 hp sbc.

Edelbrock sells stronger float valves for off road use but I did not try
them. Might work though.

--
Cheers,
Tim
http://www.racetec.cc
ò¿ó ph: (714) 695-1500
  #8  
Old December 1st 04, 08:47 PM
Steve
external usenet poster
 
Posts: n/a
Default

scott and barb wrote:

> Sounds also like a bad fuel pump.Will idle (maybe) until you try to drive
> it.Had a maddening problem like this years ago on a chevy 6.
> "sdlomi2" > wrote in message
> ...
>



I've also seen a worn fuel-pump pushrod cause fuel starvation after a
fuel pump replacement. The worn rod reduces the stroke that the fuel
pump gets cycled through, and not all pumps work as well at minimum
stroke. It may be that the old pump worked fine with the reduced stroke,
but the new one doesn't.

  #9  
Old December 1st 04, 09:30 PM
Joe6pak
external usenet poster
 
Posts: n/a
Default

I have measured the fuel pump pressure and it holds at a steady 6psi
at 1000-2000 rpms at idle. Also put a gage on one of the intake vacuum
ports and it shows steady 20 in. at idle. Also seems normal psi with
acceleration/deceleration cycles, so there don't seem to be any vacuum
leaks.
I was wondering about the fuel pump push rod. It's about the only
thing I haven't replaced or fixed. It seems like if it was a bad push rod
that it wouldn't be showing a steady 6psi at idle, but I haven't checked it
under a load yet.



"Steve" > wrote in message
...
> scott and barb wrote:
>
> > Sounds also like a bad fuel pump.Will idle (maybe) until you try to

drive
> > it.Had a maddening problem like this years ago on a chevy 6.
> > "sdlomi2" > wrote in message
> > ...
> >

>
>
> I've also seen a worn fuel-pump pushrod cause fuel starvation after a
> fuel pump replacement. The worn rod reduces the stroke that the fuel
> pump gets cycled through, and not all pumps work as well at minimum
> stroke. It may be that the old pump worked fine with the reduced stroke,
> but the new one doesn't.
>



  #10  
Old December 2nd 04, 12:20 AM
Dodge-Him
external usenet poster
 
Posts: n/a
Default

Is the carburetor nice and tight! Leak could be when the throttle is
pulled on?
Dodgem

Joe6pak wrote:
> I have measured the fuel pump pressure and it holds at a steady 6psi
> at 1000-2000 rpms at idle. Also put a gage on one of the intake vacuum
> ports and it shows steady 20 in. at idle. Also seems normal psi with
> acceleration/deceleration cycles, so there don't seem to be any vacuum
> leaks.
> I was wondering about the fuel pump push rod. It's about the only
> thing I haven't replaced or fixed. It seems like if it was a bad push rod
> that it wouldn't be showing a steady 6psi at idle, but I haven't checked it
> under a load yet.
>
>
>
> "Steve" > wrote in message
> ...
>
>>scott and barb wrote:
>>
>>
>>>Sounds also like a bad fuel pump.Will idle (maybe) until you try to

>
> drive
>
>>>it.Had a maddening problem like this years ago on a chevy 6.
>>>"sdlomi2" > wrote in message
...
>>>

>>
>>
>>I've also seen a worn fuel-pump pushrod cause fuel starvation after a
>>fuel pump replacement. The worn rod reduces the stroke that the fuel
>>pump gets cycled through, and not all pumps work as well at minimum
>>stroke. It may be that the old pump worked fine with the reduced stroke,
>>but the new one doesn't.
>>

>
>
>


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
New *FREE* Corvette Discussion Forum JLA ENTERPRISES TECHNOLOGIES INTEGRATION Corvette 12 November 30th 04 07:36 PM
87 TBI Suburban bog / acceleration problem Michael Vosk 4x4 8 September 29th 04 04:55 AM
1996 Dodge Intrepid ABS problem joe Dodge 0 June 16th 04 05:53 PM


All times are GMT +1. The time now is 11:45 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AutoBanter.
The comments are property of their posters.