what's the difference between a 350 throttle body and a 4.3, just injectors?
CK5
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4.3 vs 350 TB's
- Thread starter ryoken
- Start date
found this info, but a listing for the 4.3 isn't in it...however another reply calculates them to flow about the same as the 5.0l TBI injectors.
GM Tbi Flow Rates Measured at 13psi
[FONT=Verdana, Arial, Helvetica, sans-serif]Application[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]Color Code[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]Flow Rate lbs/hr at 13psi[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]5.0L [/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]Green/White[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]40[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]Application[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]Color Code[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]Flow Rate lbs/hr at 13psi[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]5.0L [/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]Green/White[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]40[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]5.7L Orange/Black [/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]55[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]55[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]5.7L Police package Yellow/Brown[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]own[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]68[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]68[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]*7.4L Blue/Black[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]ck[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]75[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]75[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]*7.4L DarkRed/DarkBlue[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]ue[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]85[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]85[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]* Note: These 7.4L injectors are pre'94 and used in typical GM Tbi low pressure applications. '94+'95 7.4's use a small injector with much higher fuel pressures of around 26-32psi. Do not use these'94-'95 injectors for any other application than their intended application. [/FONT]
4xcrazy
3/4 ton status
I wouldn't think they'd be different at all really, I could have swore the 4.3 uses the same piston/bore size as the 350, just two less cylinders, so the only difference I would have thought would be the fact they fire for 6 cylinders instead of 8.
Never really researched this yet, I WAS planning on it in the not too distant future though when I was going to swap out my mothers 4.3 for a 5.7.
Never really researched this yet, I WAS planning on it in the not too distant future though when I was going to swap out my mothers 4.3 for a 5.7.
well, the new rig's 4.3 TB has a few issues, high idle, etc.. got a giant return spring on it.. thinking the shaft may be a little wobbley... I've got all kinds of TB parts for 350's.. if the injectors are the only main dif, i'll mix and match some stuff together probably on the cheap..
I'm just being lazy and pre-emptive.. need to look at it sunday when I do a new tensioner pulley on it, bearings squealing like a pig...
I'm just being lazy and pre-emptive.. need to look at it sunday when I do a new tensioner pulley on it, bearings squealing like a pig...
The bodies are the same. Just the injectors. And this gives me a doah moment. I never upgraded from the 5.0 to the 5.7 on the Jimmy. 8 years now.
I had to replace my t-body because of wobbly shaft high idle. Used one from a 4.3 and just swapped injectors. Same throttle bore size between the 2. IIRC the big block TBI was the only one with bigger bores.
thanks, that's kinda what I guessed.. bolted up, just different injectors probably... need to dial that rig in a bit cuz Mutt will sort of be off the road in 2 or 3 weeks.. sort of...
Once this stuff is on the internet it's hard to change back to accurate, but not one of those are even close to what TBI injectors are rated at. Check here for accurate ratings!
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?81-GM-Injector-size-color-and-part-numbers
Yes the only difference between 5.7L, 5.0L and 4.3L is injector size. Bore size is the same. Smaller engine size is smaller bore diameter and larger engine size is larger diameter, but these three are the same. You may bump into a TPS that is straight and one that is upright, but they can be changed, there's also some differences in plugs, but again you can change them out.
Best thing to do is have the injectors serviced while TBI is off vehicle. Mr Injector services injectors, re screens (filters), flow tests and sends them back with all needed gaskets.
just checked it out... patterns looked good for 150k.. but as I suspected the shaft is as loose as a $2 ho on a Saturday night and definitely the issue...
got a near new 350 base sitting on the shelf, tomorrow I'll clean up the 4.3 stuff and swap it all over to that.... I actually have a pod spacer kicking around I may throw in for poops and giggles too...
got a near new 350 base sitting on the shelf, tomorrow I'll clean up the 4.3 stuff and swap it all over to that.... I actually have a pod spacer kicking around I may throw in for poops and giggles too...
I sent my injectors to Witchhunter Performance and had them electrically tested, flow tested, cleaned, then flow tested again after all the cleaning and they only charged $17 per injector. I know they price is a little more now but I was very happy with their service and a very quick turn around time. By the way, I sent them 454 injectors which flow tested at 94lbs/hr.
http://www.witchhunter.com/
http://www.witchhunter.com/
to be honest, I've yet to even send Mutt's 454 injectors out 
, this rig is WAY down that priority list...
and even with that, I have a pretty good "in" with an injector service out of fla (can't remember who off the top of my head).. we send them many sets a yr out of the boats... I'm sure he'd hook me up pretty good when I get around to it...
, this rig is WAY down that priority list... and even with that, I have a pretty good "in" with an injector service out of fla (can't remember who off the top of my head).. we send them many sets a yr out of the boats... I'm sure he'd hook me up pretty good when I get around to it...
