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girlcrazy_4
03-28-2010, 09:23 PM
Engine is a 1977 Olds 403 It revs wonderfully in park, but once its in gear it sputters and runs crappy. When driving around the engine runs great unless you stomp it and it boggs and almost dies than picks up power again. This sound like a carb issue?

mus-Tard
03-28-2010, 09:35 PM
sounds like fuel to me.

regulate34
03-28-2010, 10:14 PM
x2 on the fuel
check fuel pressure and clean your carb

girlcrazy_4
03-29-2010, 12:20 AM
Not sure if anyone would know, I am wanting to eliminate all the vacuum lines on this big of a engine. Know of any places where to start?

Tinker
03-29-2010, 12:35 AM
If you have already started to Fawk with the vacuum lines, I would say that is where the problem lies. If not probably a bad vacuum leak somewhere like an intake gasket. Try running a non lit propane bottle around the engine and if it idles up you have found the problem.

4skin
03-29-2010, 12:37 AM
what are you running it in you should be able to rip it all off pin distriutor no vacume advance but dont think thats your problem sounds like carb fuel isue

4skin
03-29-2010, 12:41 AM
sounds like no acelerator pump shot

FZJ80
03-29-2010, 04:21 AM
X2 On the accelerator pump, is it still the Qjet on there?

m j
03-29-2010, 04:58 AM
accellerator pump shot

Apathy
03-29-2010, 06:35 AM
accellerator pump as well, or the bushing on the Q jet are worn and leaking.

m j
03-29-2010, 06:37 PM
its a quadrajet we know the throttleshaft bushings are shot too :)

dirka dave
03-29-2010, 06:41 PM
Modulator on the transmission maybe.

mus-Tard
03-29-2010, 08:26 PM
if the accellerator pump was pooced it would lean out and stall if you reved it in park, the vaccume would drop off and there would be not enough air flow over the venturi to suck the fuel out at low rpm. may want to toss a vaccume gauge on it just to check what its like. but l would look into fuel filter or clean the carb.

kootenaycat
03-29-2010, 08:37 PM
Sounds like accelerator pump not working but also check the secondarys. Take the air cleaner off and (motor off and warmed up so the primary side choke is open) push on the secondary air flap, it will probably have little or no tension to return to the closed positin. Q-Jets were bad for the return spring breaking. When you stomp on the throttle (under load) the secondary air flap opens too soon leaning it out. An easy fix and can be done without removing the carb but for what it takes, just re&re the carb.

Might as well check the timing too if the carb checks out ok, retarded timing will cause major bogs and usually a backfire up the carb (just like a lean condition)

girlcrazy_4
03-29-2010, 10:06 PM
what are you running it in you should be able to rip it all off pin distriutor no vacume advance but dont think thats your problem sounds like carb fuel isue

Its not in a truck, but I'm building a hit to pass car. Its in a olds cutlass 98 with a t350 trans as far as I know. I eliminated most of the excess vacuum lines today and seems to run alot better. In park it has instant throttle response and seems to run very well. Bogging in drive seems to be much less, but hard to tell in the driveway. It has been bogging under WOT most of the time. I`ll have to look into this more in a few days once I have electrical hooked up once again since the front clip is off the car.

Ah, there isnt a better place to talk about engines than on here on FIBC [36]
Here is sunday night
http://img.photobucket.com/albums/v488/girlcrazy_4/DSC00853.jpg

4skin
03-29-2010, 10:25 PM
:dontknow: try nother carb we use qwadra bogs for door stops :D

89burban
03-29-2010, 10:25 PM
I had that issue with my old car.. for me it was my fuel pump. Enough gas for idle, but no where enough for driving.

girlcrazy_4
03-30-2010, 12:35 AM
So I`m new to oldsmobile. Is this 403 a small or big block?? Are any of the parts compatible with a 350?? valve covers, carb, headers etc. I havnt been able to find much info anywhere. Fuel pumps interchangable??

kootenaycat
03-30-2010, 08:51 PM
Its not in a truck, but I'm building a hit to pass car. Its in a olds cutlass 98 with a t350 trans as far as I know. I eliminated most of the excess vacuum lines today and seems to run alot better. In park it has instant throttle response and seems to run very well. Bogging in drive seems to be much less, but hard to tell in the driveway. It has been bogging under WOT most of the time. I`ll have to look into this more in a few days once I have electrical hooked up once again since the front clip is off the car.

Ah, there isnt a better place to talk about engines than on here on FIBC [36]
Here is sunday night


If it bogs under WOT most of the time I'd bet the secondary spring is just weak. It's an easy adjustment and can be done in vehicle but it helps to have a small mirror to help put the allen wrench in the set screw.
125074

Here's a couple of sites on the Qjet
http://www.carburetor.ca/carbs/tech/Rochester/Quadrajet-index.html
This one has a good explanation of adjustments
http://vetteworks.tripod.com/qjet.htm

:dontknow: try nother carb we use qwadra bogs for door stops :D
Qjets weren't the best street performer but work awesome for off road and a good street carb, central float bowl, small primarys and big secondarys for instant response. I'd take a Qjet over a Edelbrock or Holley anyday, easy to work on and when you know how to tune one they perform great. Just wouldn't use it on a 1/4 mile car. :D

4skin
03-30-2010, 09:14 PM
id take q jet over edelbrock 72 gmc we restored has one works great
im not much of carb guy can tune holey purde gooder like demon carb
some classes have to run oe carb they make em rock

FZJ80
03-30-2010, 09:16 PM
With the engine off look down the primary bores, slowly open the throttle all the way, you should see a steady stream of fuel entering the bores for most of, if not all the throttle travel.

fullsizebronco
03-30-2010, 11:53 PM
and maybe some carb clean that thing is a mess lol and what the frick does WOT mean ?

4skin
03-31-2010, 12:00 AM
[36] wide open throtle[36]
for maximus aceleratus:D :D :D

fullsizebronco
03-31-2010, 01:12 AM
frick as easy as that eh i was trying to think of all the things it could have meant haha

dirka dave
03-31-2010, 05:17 AM
:dontknow: try nother carb we use qwadra bogs for door stops :D


Hey man, the q-jet is one of the best carbs ever made...IMO

girlcrazy_4
03-31-2010, 07:58 AM
A local shop is hooking us up with a fully rebuilt carb, and tunage once the season is about to begin. Fuck yeah

Renegord
03-31-2010, 08:43 AM
I had a similar problem with a car I used to have . Turned out to be the auto choke , I disconnected the choke linkage , and it ran great , but had no choke . Fortunatly in B.C. it rarely gets cold enough to actually need one.[cheers]

Apathy
03-31-2010, 08:44 AM
BTW.. the 403 olds is a agreat motor. My mom had one in here 78 Trans am.

thing was AWESOME.. top end in that heavy pig was about 140MPH.
But i could just put my foot on the floor and it would sit and roast em

fullsizebronco
03-31-2010, 11:52 AM
what shop is this! is it the one im thinking of?!

girlcrazy_4
03-31-2010, 06:22 PM
what shop is this! is it the one im thinking of?!

you'll see once the car is painted [cheers]

hrd4mud
04-08-2010, 10:29 AM
Everyone is talkin fuel or vacume leaks, but nobody mentioned spark.

In my 01 Ram it was runnin exactly like you describe. New truck has a funny lookin coil right behind the fan, so every mudhole i went in packed into the coil, would idle fine through about 2500-3000 rpm anything over that ran exactly like you describe. Was told I had cracked heads everything. Figgured Id try the 40 dollor coil first and ran better then ever. My computer gave me the extreamly helpful code of multiple missfire LOL.

4skin
04-08-2010, 11:01 AM
Everyone is talkin fuel or vacume leaks, but nobody mentioned spark.

In my 01 Ram it was runnin exactly like you describe. New truck has a funny lookin coil right behind the fan, so every mudhole i went in packed into the coil, would idle fine through about 2500-3000 rpm anything over that ran exactly like you describe. Was told I had cracked heads everything. Figgured Id try the 40 dollor coil first and ran better then ever. My computer gave me the extreamly helpful code of multiple missfire LOL.
:D note its general motors no wierd coils and flutter stats
:D note it does not have a computer
:D note it has a carburator
just saying

hrd4mud
04-08-2010, 12:50 PM
Ya I know, Im just sain dont completely ignore the spark side. It will still have a coil, and the vacume advance could be screwing up, etc. Ive even had a new sparkplug completely stop firing within one month of install.

And my point with the computer was even the computer had no idea what was causing it, so no help, just that it was missfiring.

Id start by sniffin the tailpipe after it has the issue, if ya smell gas its prob a spark related iussue, if ya dont then try all the other suggestions.

hrd4mud
04-08-2010, 12:51 PM
but what do I know, Im just an accountant :party0010:

Happypants
04-08-2010, 12:58 PM
Same thing happens to me in the jeep when I'm in too deep of water, check under ur dizzy, clean the points and you rotor as well, also how old are the plugs?? Mine were bridged in my jeep, but I also hadn't replaced the plugs in 4 years either, check ur fuel filter in the carb or in line, check the jets?

kootenaycat
04-08-2010, 08:48 PM
Same thing happens to me in the jeep when I'm in too deep of water, check under ur dizzy, clean the points and you rotor as well, also how old are the plugs?? Mine were bridged in my jeep, but I also hadn't replaced the plugs in 4 years either, check ur fuel filter in the carb or in line, check the jets?


Umm, I think you found your problem. :D

4skin
04-09-2010, 01:34 AM
:D :D mmmn isnt jeep and dodge same thing:D

Happypants
04-09-2010, 12:09 PM
Umm, I think you found your problem. :D

Pfft,

nebowe
04-09-2010, 06:47 PM
try disconnecting the vacuum modulator at the tranny????