Throttle Body Confusion

[psalm10720]

I had posted a post regarding a carburetor issue I was having with my Brave "falling on it's face" after warm-up. I'm not a mechanic and yield to the experts. The term Carburetor was used to me by professionals and so looking at the unit and listening to local professionals I had it in my mind that the unit was a carburetor but I was wrong. It is a throttle body injector that looks like a carburetor. I sent it to a speed shop and spent a huge amount of money and they got a Holly Unit tried to make it work then found out from Holly that unit would not work. They did some other stuff which has helped but I found a carburetor shop in my area that has a good reputation so I will send it to them when I can. I really believed in my mind based on the looks of the unit and what I was told by other professionals that it was a carburetor but they and I were wrong... Sorry.

[RLS7201]

psalm10720 wrote:
It’s a P30 chasis not P32. I only come in a short time each month. Situation is ok. Will post if I need assistance. Case closed.

That's backwards. Chevy class A motor home chassis are P32. Chevy truck chassis are P30. But the P32 chassis has been misidentified for years. Even the generic parts houses has it wrong in their computers.
I've actually seen the P32 parts books at a GMC dealer.

Richard

[psalm10720]

Yes it is a throttle body. I am a neophyte when it comes to some issues. It looks like a carb but it is a throttle body. When funds allow I will have it rebuilt. I apologize for the confusion but it looks like a carb to me and that's what a shop referred to it as.

The good news is the work they did other than changing or rebuilding the throttle body has made the engine run smoother and not falter on acceleration.

I only drive it short distances each month from Parking spot to RV Park and back again.

Thanks again for all the feedback...

[10forty2]

udidwht wrote:

10forty2 wrote:
I used to have a 1988 Chevy pickup with TBI. It got to stumbling and running like an old dog. Turns out it was only the throttle body gasket that needed replacing. Took a 10mm socket and about 30 minutes to fix.....

Gasket as in the intake manifold > TBI gasket?

It was listed as the Throttle Body Gasket when I got it....it was between the TB and the intake. Best I remember, there were two bolts holding the TB in place....removed them, slightly lifted the TB, removed the old gasket and replaced it with the new one.

[timmac]

psalm10720 wrote:
1993 Chevy 454 P30

That year is a fuel injected throttle body

[tropical36]

psalm10720 wrote:
It’s a P30 chasis not P32. I only come in a short time each month. Situation is ok. Will post if I need assistance. Case closed.

Actually it is a P32 for a motorhome and the term P30 is purely generic.

[udidwht]

10forty2 wrote:
I used to have a 1988 Chevy pickup with TBI. It got to stumbling and running like an old dog. Turns out it was only the throttle body gasket that needed replacing. Took a 10mm socket and about 30 minutes to fix.....

Gasket as in the intake manifold > TBI gasket?

[10forty2]

I used to have a 1988 Chevy pickup with TBI. It got to stumbling and running like an old dog. Turns out it was only the throttle body gasket that needed replacing. Took a 10mm socket and about 30 minutes to fix.....

[udidwht]

Stim wrote:
TBI's are dirt dumb simple.
I still have one in my shop attic from over 20 years ago.
Guess I should put it on ebay. ???
It was common for the fuel pressure regulator in the TBI to get weak and they are cheap/easy to change. TBI has a supply and return line.
As stated, fuel pump maybe and/or frame filter.

Yes they are easy to replace (regulator). Ones biggest worry in that job? Dropping one of the bolts down the TBI throat while disassembling or reassembling it.

Take your time and more importantly carefully fold Scott's towell or such over the TBI throats before working on it.

Those regulator diaphragms are made of Viton and do not fail often and generally do not strand one. There really isn't much to rebuilding one given the kit is primarily made up of seals. I've rebuilt them without even taking the TBI off the intake. It can be done if your certain the intake manifold gasket is good.

As long as one makes it a good habit to replace the fuel filter every 15k the TBI will live a long life. Likely longer than the owner.

[theoldwizard1]

psalm10720 wrote:
When am able taking throttle body to well-respected Tampa area Carb shop for a rebuild. They do an entire rebuild for $399.00

If it is a standard GM TBI, that is a rip off !

As Stim said, TBI is "dirt, dumb simple".

[theoldwizard1]

Stim wrote:
It was common for the fuel pressure regulator in the TBI to get weak and they are cheap/easy to change. TBI has a supply and return line.
As stated, fuel pump maybe and/or frame filter.

Concur !

[RLS7201]

psalm10720 wrote:
It’s a P30 chasis not P32. I only come in a short time each month. Situation is ok. Will post if I need assistance. Case closed.

Actually the general public has been misnaming the P32 chassis for years. The P30 chassis is a commercial chassis where as the RV chassis is really a P32 chassis. But it's irrelevant, calling your chassis a P30 will get you the correct parts most of the time.

When GM made the motorhome chassis it was initially designated a P32 and was never really officially recognized as a P30 except for ease of conversation and convenience.

Most publications, people and marketing types simply dropped off the "2" and the chassis became more commonly known in speech and print as a P30.

The differences in between the P series is blurred and to a GM engineer there wasn't any difference between a motorhome chassis whether it is spoken about as a 30 or a 32 it was simply recognized as a P series.

When WCC got the product the marketing efforts and literature pointed to a P32 Wide-Track designation however in reality to the technician types it was simply a P Series. Later we see the chassis guides dropping or never having mentioned 30 or 32 and simply describing the product as a P series.

Now please don't introduce any other model types into the mix because the P32 was designed to be a motorhome chassis as opposed to a commercial product. I understand that the placement of the steering wheel column is the biggest difference between a P30 commercial and a P32 motorhome chassis.


Richard

[enblethen]

Let us know how it goes!
Maybe information will help others.

[psalm10720]

When am able taking throttle body to well-respected Tampa area Carb shop for a rebuild. They do an entire rebuild for $399.00

[77rollalong]

the early GM fuel injection was really simple, have had a few with a stuck injector that just stream fuel without the engine running, few with fuel pressure regulator leaking back too much, quit a few that the MAP sensor fails, which in most cases will throw a code. pulling codes off the GM obd1 systems you just need a paper clip to jumper two pins on the obd port, then read the check engine light in the light flashes like morse code.