Have a 93 Brave 27RC on a Chevy P30 chasis. 112000 miles. When cold idles well and accelerates well from standing still. Then after warmup when accelerating from a start it falters often. Some refer to it as “falling on its face” or “backfiring” without the loud noise. One of the possible explanations refers to the “accelerator pump” on the carburetor. Another which sounds more plausible is the ECM has a problem because the programming during warmup is different than after the engine is warmed up... Anybody with experience?

No carburetor, it's fuel injected. I would replace the 02 sensor first. It/they should have been replaced by now and if not, are in desperate need. (They get lazy and slow but work well enough not to throw a code) When eng is cold it isn't a factor.Also make sure every other service has been done to it.

It could be the IAC(idle air control) It is mounted on the right side of the throttle body assembly. It acts similar to a choke on a carb engine. The passages could be clogged with carbon.IAC

Find an OLD mechanic for the repair of this 25 year old RV.

93 are throttle body injection. The throttle body looks like a two barrel carb. Verify your vin number, the tenth character would be a "P" for 1993, 1992 would be the letter "N"Remove air filter and look into the throat, there should be two injectors at the top. They are about 1 inch diameter and two inches long, each have an electrical connector.If someone changed out motor that could have carb.Then all bets are off until you find engine vin number.

93 Brave with Chevy 454 acceleration issuea | Good Sam Community

enblethen
Nomad
Mar 07, 2018
My cheap books says all the way back to 1987 7.4 engine had TBI.
ScottG
Nomad
Mar 07, 2018
Pretty sure it's TBI. Carbs just couldn't do emissions by then.
They look like carbs since everything is in one spot.

Strongly suggest replacing the 02 sensor which is dirt cheap and easy to replace yourself.
Also make sure there's no exhaust leaks at the manifold which will mess with sensors.
enblethen
Nomad
Mar 07, 2018
93 are throttle body injection. The throttle body looks like a two barrel carb.
Verify your vin number, the tenth character would be a "P" for 1993, 1992 would be the letter "N"
Remove air filter and look into the throat, there should be two injectors at the top. They are about 1 inch diameter and two inches long, each have an electrical connector.
If someone changed out motor that could have carb.
Then all bets are off until you find engine vin number.
Lwiddis
Explorer II
Mar 06, 2018
Find an OLD mechanic for the repair of this 25 year old RV.
psalm10720
Explorer
Mar 06, 2018
Mine is carbureted
enblethen
Nomad
Mar 06, 2018
It could be the IAC(idle air control) It is mounted on the right side of the throttle body assembly. It acts similar to a choke on a carb engine. The passages could be clogged with carbon.
IAC
ScottG
Nomad
Mar 06, 2018
No carburetor, it's fuel injected.
I would replace the 02 sensor first. It/they should have been replaced by now and if not, are in desperate need. (They get lazy and slow but work well enough not to throw a code) When eng is cold it isn't a factor.
Also make sure every other service has been done to it.

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93 Brave with Chevy 454 acceleration issuea

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