TBI EGR issue.

[RawbDidIt]

Ah, I missed the part of sputtering while cruising but ok everywhere else.

Agree with not switching to carb, it's more expensive than it seems when you factor in everything else you need. Just to clarify from before, you don't need a vacuum pump to test the vacuum system, just a vacuum gage. Harbor freight sells them for pretty cheap, and they get the job done. Amazon has a ton available too.

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[Allen4rmGromLak]

I wouldn't go with a carb. That's like going back to the 60s technology. There's a lot more involved than just throwing a carb and a cam at it. What year truck do you have, does it have a 4l60e trans? How are you going to control it and the dizzy? Some basic questions to start...

I have a 1994 with a NV4500 so no issues with the trans. The dizzy will be a HEI, controlled by ignition source. The fuel pump is already wired up thru a "aftermarket" relay, entirely bypassed the ECM or I could go mechanical fuel pump but vapor lock isn't fun. Already have the fuel pressure regulator with bypass and the M16&M14 to AN6 adapters. The choke will be manual with a 600 Holley Double pumper with mechanical secondaries. (Daily drive this carb since I was 15, currently on my 66 F100 with 390)

So basically the engine will run off one wire. And the ECM will be eliminated. Done it to a 91 1500 orginally a V6 truck but now it has a carbed 350 he used a Carter carb with TPS mount, he wanted to keep the automatic

I have lived my entire adult life with a Holley or edelbrock carb. The only car with fuel injection is this 94 and my wife's "nice" ride, but her daily driver is a 67 VW.

 

[Allen4rmGromLak]

Agree with not switching to carb, it's more expensive than it seems when you factor in everything else you need. Just to clarify from before, you don't need a vacuum pump to test the vacuum system, just a vacuum gage. Harbor freight sells them for pretty cheap, and they get the job done. Amazon has a ton available too.

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Yep downloaded the service manual, I already have a gauge. But you can literally suck on the EGR nipple and just pull the air out. Its not sticking to your tounge for very long, maybe a second.

I already have everything including the cam and intake and carb. Just need to buy the GM Crate engine when I get some vacation saved up. My shop is full of weird stuff. I could probably build a engine with the parts I have but for 2100 bucks for NEW GM engine. Can't beat that.

 

[PlayingWithTBI]

I have lived my entire adult life with a Holley or edelbrock carb.

Well, enjoy living in the 60s.

 

[Allen4rmGromLak]

Well, enjoy living in the 60s.

If there was a EASY way to tune the ecm for the L31, cam, and headers then I would look into it. But I'm still left with the low preforming TBI. I'm shooting for 375 HP with 450 ftlb with my Dart Sportsman heads. If the TBI can handle that, then let's do it. For the most part the TBI is reliable. After all 300k miles on this truck.

 

[PlayingWithTBI]

If the TBI can handle that, then let's do it

It can, I have the Edelbrock Performer 3704 intake with a bored out 46mm TB (which flows 650CFM) and 7.4L injectors on top of Summit Racing 162108 heads (made by Trick Flow) on my 5.7L L05 block among other things. I have the Dynamic EFI EBL Flash2 ECM - much faster baud rate (8192 over 160 IIRC), extended tables, and makes it easy to tune.

https://www.summitracing.com/parts/edl-3704
https://www.ebay.com/str/sprperformance
https://www.summitracing.com/parts/sum-162108/overview/make/chevrolet
https://www.dynamicefi.com/EBL_Flash.php

 

[Allen4rmGromLak]

That's way more expensive than a carb setup. I will stick with what I know and already have parts for. I have NEVER been stranded on the side of the road with a Holley. My 66 gets about 21 mpg on the freeway with a C6 trans.

 

[Allen4rmGromLak]

PlayingWithTBI

Question for you. Can I run a L31 vortec crate with say a XR264HR-10. 4 barrel intake with TBI adapter, and a HEI distributor? Or do I have to keep the factory dizzy? Any computer tune?

Like I said, no idea about FI other than what's stuck on my truck.[/QUOTE]

 

[PlayingWithTBI]

If you're going with an L31 Vortec you should probably go with MPFI and upgrade your ECM. Other folks here have done this and may want to weigh in.

 

[L31MaxExpress]

If there was a EASY way to tune the ecm for the L31, cam, and headers then I would look into it. But I'm still left with the low preforming TBI. I'm shooting for 375 HP with 450 ftlb with my Dart Sportsman heads. If the TBI can handle that, then let's do it. For the most part the TBI is reliable. After all 300k miles on this truck.

A single 454 TBI unit maxes around 450 HP. I have squeezed 330 hp out of a stock bore small block TBI unit. The TBI itself is almost never the issue. Its the lack of tuning. For the hotrod TBI stuff I prefer the Victor Jr 2bbl intake.

I use TunerproRT and a Moates AutoProm to real time tune GM OBD1 ECMs. I can alter ANY engine parameter in the computer with the engine running.