Barthmobile Portal
454 CARB

This topic can be found at:
https://www.barthmobile.com/eve/forums/a/tpc/f/3631087061/m/2991039061

07-27-2005, 01:19 AM
timnlana
454 CARB
I feel like a monkey with a football, I need some help.

1973 Barth 25 footer
The facts:

1) 454 with stock four barrel
2) Carburetor just rebuilt.


Coach ran OK after rebuild.
Ran out of gas.


NOW
Coach backfires when I press down hard on the gas.


Action items.

Replaced fuel filter. This helped a little.
General check linkages and lubricate around carburetor.
New spark plug wires.

Now I realize this is not much of a foundation but HELP. If I can get it to run I’m taking it back to the guy that did the CARB but hey I’d love to fix it at home.

It sort of acts like it is fuel starved.

So once again HELP.

Timothy
07-27-2005, 01:28 AM
bill h
Check fuel pressure while driving. A vacuum gage can also be used as a fuel pressure ind.

Check float level and float valve.

Check vacuum lines and the devices in the emissions system.

Check distributor advance mechanism for freedom and Red Death.

Check distributor vacuum advance.

Check to see if power enrichment piston is free and power needles are free to move.

Which filter did you replace, the one in the carb inlet or the one underneath?
07-27-2005, 03:52 AM
frazierds
This may sound silly, but check to see if the needles got bent when there was heat but no gas when you ran out of fuel.
Papa Don
07-27-2005, 09:03 AM
Lee
My first thoughts are:

A fuel tank, built in 1973, is sucked dry, followed by lack-of-fuel symptoms from a recently rebuilt carb that worked fine previously = fuel flow issues = making sure
that BOTH fuel filters are good......followed by fuel pressure issues, i.e.: electric booster pump go south?

After that, I'd wonder whether or not I'd inadvertently messed-up or disconnected a vacuum line to the carb......

Been there - done that....Good Luck!
07-27-2005, 03:23 PM
timnlana
Gentlemen:

Thank you, I'll run down your check lists and let you know.


Timothy
07-28-2005, 04:50 PM
rigajake
quote:
Originally posted by timnlana:
I feel like a monkey with a football, I need some help.

1973 Barth 25 footer
The facts:

1) 454 with stock four barrel
2) Carburetor just rebuilt.


Coach ran OK after rebuild.
Ran out of gas.


NOW
Coach backfires when I press down hard on the gas.


Action items.

Replaced fuel filter. This helped a little.
General check linkages and lubricate around carburetor.
New spark plug wires.

Now I realize this is not much of a foundation but HELP. If I can get it to run I’m taking it back to the guy that did the CARB but hey I’d love to fix it at home.

It sort of acts like it is fuel starved.

So once again HELP.

Timothy


07-31-2005, 07:35 PM
carl buckstad
timnlana it is your accelerator pump if pump is not working when you step on gas engine will go lean and backfier. could be dirt. carl
08-10-2005, 04:44 PM
timnlana
Toughly convinced that the gentleman that had rebuilt my carburetor had not done things carefully I took the Barth back to him. The Barth would run if I did not give it any gas, as soon as I asked the Barth to accelerate under load it would backfire. If I was in neutral it accelerated nicely, well better than under load anyway.

The gentleman that the rebuilt the carburetor pointed out that if the spark plug wires were installed in the correct order the Barth would run better, this proved to be the case.

Well Barth has a new fuel pump, new fuel lines, new filters (both of them), all sorts of new stuff in the distributor and now correctly sequenced new spark plug wires so all I have to do is learn how to set the dwell and time it and we are off and running.



[This message has been edited by timnlana (edited August 10, 2005).]
08-10-2005, 04:55 PM
olroy
Hopefully, the gentleman didn't have too much sarcasm in his voice when he advised you. I went through the crossed-wires syndrome with a Dodge van many years ago, but thankfully, discovered the problem by myself.

[This message has been edited by olroy (edited August 10, 2005).]
08-10-2005, 05:30 PM
timnlana
Olroy:

There was a price extracted from my ego but when I asked him to look at things I carefully listed what I had done and the symptomatic changes when I did so. This allowed him to isolate the failure in just a few moments so the ego price was low and the financial cost was zero.

The points of my cautionary tale are:

1) Check the documentation, assumptions are deadly.
2) Even though the fix was unanticipated the learning and the work remain valid.
3) Tell your mechanic the truth; this will reduce the time required for fault isolation. In my experience the work time is generally much shorter than the fault isolation period.


Timothy
08-10-2005, 05:47 PM
bill h
There is a way to install plug wires in such a manner as to be fine except for all-out accelleration. Nothing dramatic, just a little down on power.

Ask me how I know. Took me a while to figure it out, too. Ever since, I have used Accel numbered clips on the wires. Or, on OTB wires, a marker pen.
07-17-2008, 10:45 AM
BarthBluesmobile
Here is some info that might be of use to us with 1985 and 1986 rigs with the 454. I think that the 87 model year would use a TBI system. But in the transition year, there might be some. Earlier years might find this useful as well. My 86 has a Quadrajet, with number 17085212. This is an 800 CFM quadrajet. If you need that carb, the numbers 17111349, 17085004, and 17111353 are similar models. I think that they might be for manual transmission carbs, and the last two are for the California emissions equivalents.

This carburetor has an electric choke. The earlier years will have a thermal choke. The earlier years will also have less "tamper proof" provisions, but I am not sure of this. This carburetor, if you find an NOS one, will be Delco 24-3545. Not that you’d find a government surplus one, but the federal NSN is 2910-01-297-8427.

There are rebuilders of this carburetor with listings on Ebay.

Holley # 64-70113 exact, 65-1904 close. Interesting to note that 1904 is the Edelbrock number, if you’d find one from that brand. That carb is not from Edelbrock anymore. Perhaps they sold the product line to Holley.

Happy Motoring!
Matt


1987 Barth 27' P32 Chassis
Former State Police Command Post
Chevrolet 454
Weiand Manifold, Crane Cam, Gibson Exhaust
07-17-2008, 05:26 PM
olroy
TBI came later than '87. My '90 had a Quadrajet.