Hi chaps,

Hope you can help me. I have a problem with my TBI (sheared bolt) and need to replace it as a matter of some urgency – due to go on family vacation next week.
It’s a 1991 Chevy P30 Motorhome with a 7.4L 454 TBI
Auto trans 4L80E and references my engine variant ,7.4L(7.4N),V8(E.F.I.) 7.4N(L19)
Vin code is 1GBJP37N0M3301377
The Production casting number on the broken throttle body (17091045) from my Motorhome. It all lines up to the 7.4 454 with engine code N automatic transmission.
I was on the verge of ordering a AC Delco replacement (17112563) but I phoned them to check and they gave me a different part number over the phone (17112557)

I have a 1991 truck parts catalogue (not sure it is Motorhome specific), found the reference to the production casting number on my broken throttle body and it says the replacement is yet another part number (17112569).

So, I have multiple suggestions (17112563, 17112557, 17112569) and not sure which one to try and get. There seems to be quite a price/availability differential as well.

Would you be able to advise which one to go for? I’m based in the UK, so need to get this shipped over really quickly.

 

Looks like all 3 of your numbers as well as many others point to TBI Model 220 http://www.throttlebodyinjection.com/TBI_Catalog.htm Injector size is obviously different, but since you are only concerned with the body, I'm not sure that the part number matters that much. Differences could possibly include difference in the vacuum ports and/or throttle linkage. Either way, I think you could make it work, if it wasn't an exact match. FWIW, I would try to get the 17112569 if you can find it, since you have a book that indicates it is a replacement for your 17091045. If not, rely on the AC Delco guy.

 

Hi there! Appreciate it's been a few years since this post but curious which part the OP went for and if it was compatible? Got a '92 Chevy 7.4l V8 needing throttle body replaced.
Thanks!

 

WHY does it need to be replaced?

Usually, it's simple, cheap, and effective to merely rebuild the thing; with the most-difficult/expensive part being to re-bush the throttle shaft area in the casting. This can be a D-I-Y process if you buy the special drill bit and bushing kit from Cliff Ruggles or some other source. Most folks subcontract the bushing installation to an automotive machine shop, where the machinist merely bores it out and crams in a thinwall bronze valve guide cut to size.

If you do this yourself, be sure to grind the threaded ends of the throttle plate screws. They're staked--you'll break the screw before it turns out unless you grind off the deformed threads.

A couple of bottles of Techron Complete Fuel System Cleaner in the gas tank would likely return the injectors to usable condition--nicely cleaned inside.

A rebuild kit including a pressure regulator diaphragm, some gaskets, etc. is cheap and easy to install. Overall, about 1/10 the skill and effort of a Quadrajet overhaul.

 

Sorry.