Guys that swapped from a tbi to a carb what did you do for the fuel line ??I would like to leave the tbi lines in there and not cut them up. You guys have any soulutions ??
CK5
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tbi to carb ??
- Thread starter dheavychevy38
- Start date
If you don't want to butcher those lines, cheapest and easiest is probably getting the Saginaw fitting "repair" ends from an auto parts store so you could run a hose off the end of the stock fuel line.
Earl's(?) makes a -AN adapter, but those are pretty pricey, I would expect the Saginaw repair end would be cheaper.
I'm assuming you intend to keep the in-tank pump.
Earl's(?) makes a -AN adapter, but those are pretty pricey, I would expect the Saginaw repair end would be cheaper.
I'm assuming you intend to keep the in-tank pump.
F-ingrob
Wheres the mud
Earl's -AN adapter
Stomis
Professional Amateur
Ok I'll be the first since this site has such a track record to persuade people not to do this lol.
Why are you getting rid of the TBI?
Why are you getting rid of the TBI?
Amillionoh7
Registered Member
I know you don't want to cut the line but it is very simple to cut the line and flare the end with a brake line tool. then you have a secure connection that wont leak and only cost 5$. the last thing you want is fuel shooting straight on the exhaust.
Amillionoh7
Registered Member
you are going to have to modify the line anyway to go to a fuel pressure regulator or a mech. pump
If it were me, and possible, I'd use the Earl's -AN adapter from factory line directly into a regulator then into rubber. Probably the "safest" way to prevent leaks.
*If* I had any interest of going backwards on how my vehicle runs. Sorry, couldn't help myself.
*If* I had any interest of going backwards on how my vehicle runs. Sorry, couldn't help myself.
I am with stomis,why?????
Well since you asked. I am looking to put a carb on just to get it running and driveable for a backup vehicle. Unfortuantly it has sat for almost 2 years cause of a random stall issue. In those 2 years i have installed almost all new parts on the fuel side and ignition side of things. I know how you guys feel about swapping to a carb. When she ran she ran great but i just cant seem to track down my headache and am tired if seeing her sit in the yard.
In that case it's way more work (and expense) to swap to a carb than it is to just fix the problem.
I looked through your old threads, I saw a couple of questions here and there, but nothing showing you actually dug into the problem, or what problem it has now.
I looked through your old threads, I saw a couple of questions here and there, but nothing showing you actually dug into the problem, or what problem it has now.
Amillionoh7
Registered Member
I very much agree with dyeagerI swapped my camaro from tbi to carb which involved buying (cam,fuel pump, carb style tank pickup,non computer controlled hei dist, intake manifold, carb, throttle linkages, tv cable linkages, and probably 200$ in odds and ends.)
the reason i switched was because i added a large cam and headers and wanted to be able to tune it myself.
The grass only looks greener. I promise getting the carb setup running will have just as many problems to sort out as the existing TBI setup does. But of course then you'll be out the time and money of the conversion. Oh yeah, and get worse gas mileage, start poor in the winter, etc.
I bet if you add up the cost of all parts you will need for the conversion, you could tow it to a shop and have them fix it for the same money. Not to mention tons of time you'd save.
I also bet if you started posting up symptoms and such they guys here would walk you through getting it running in a couple of days.
I bet if you add up the cost of all parts you will need for the conversion, you could tow it to a shop and have them fix it for the same money. Not to mention tons of time you'd save.
I also bet if you started posting up symptoms and such they guys here would walk you through getting it running in a couple of days.
Stomis
Professional Amateur
Yeah let's hear it. Give us the run down.
Just like most of you guys i have had many of projects and many of parts left over lol. I have 90% of what i need to swap to a carb. But you guys have talked me into trying to get her running again with the tbi before i do anything crazy. The problem was when driveing down the road it would randomally stall at stop lights. It would fire tight back up but over time that went down hill also. As of right now she will start somedays but most times wont. If it does start the minute you put it in gear it dies.
It has a new coil,new wires, new cap, new rotor, new plugs, new tps, new iac. The fuel pump is produceing 9-10lbs but i also have a new one of those to go in as well. Now before you guys say stip buying parts lol. All these parts where given to me minus the fuel pump from a good freind who installed all of these and his truck was totaled.
The good thing is now that it's pretty consistent, it's going to be easier. If it was 100% no-start, it would be super easy, but oh well.
Really need to do a very thorough look-through of the engine bay. Check all wires, all wiring plugs (even to the point of disconnecting and checking their condition) all vacuum hoses, then test for vacuum leaks. I've not done it, but an unlit propane torch I think would be a lot cleaner than the various other methods I've heard mentioned for looking for vacuum leaks.
After that...
Your fuel pressure should be enough to get it started. I assume it was 10PSI, pretty stable when running, regardless of throttle position? How long ago did you do this test? May be worth repeating if you do not know if the fuel pump hose in the tank has been replaced with an ethanol-safe piece. Watching the "leakdown" of pressure after engine shutdown may tell you if that hose is split, but from what I've seen, your running pressure will be low and that is your first clue. With my TPI, and a split hose, I was getting ~24PSI from a pump that should have been pushing 43.5. With the lower pressure of TBI, the amount of pressure lost might be a bit less.
I found a leakdown rate given in a 1970's GM fuel injection manual which I can't find now, but it was something like no more than 2 PSI (from 39PSI running) in a 30 second period. That was in regards to a regulator failure, but nonetheless, is probably a basic guideline for how long the system should maintain pressure. I've not seen that leakdown rate in a newer manual.
Does this link work? http://www.mediafire.com/download/i...Fuel_and_Emissions_Including_Driveability.pdf if it doesn't, use the link in my signature for the proper year manuals, and download them. PDF page 61 of the 1987 fuel and emissions manual shows the resistance values (approximate) for the coolant temp sensor, and I know a fair number of people have had issues with either the connector, or the CTS itself. I'd want to know with a dead cold engine (so it's approximately same temperature as it is outside) that the CTS is reading close to ambient temp.
Really need to do a very thorough look-through of the engine bay. Check all wires, all wiring plugs (even to the point of disconnecting and checking their condition) all vacuum hoses, then test for vacuum leaks. I've not done it, but an unlit propane torch I think would be a lot cleaner than the various other methods I've heard mentioned for looking for vacuum leaks.
After that...
Your fuel pressure should be enough to get it started. I assume it was 10PSI, pretty stable when running, regardless of throttle position? How long ago did you do this test? May be worth repeating if you do not know if the fuel pump hose in the tank has been replaced with an ethanol-safe piece. Watching the "leakdown" of pressure after engine shutdown may tell you if that hose is split, but from what I've seen, your running pressure will be low and that is your first clue. With my TPI, and a split hose, I was getting ~24PSI from a pump that should have been pushing 43.5. With the lower pressure of TBI, the amount of pressure lost might be a bit less.
I found a leakdown rate given in a 1970's GM fuel injection manual which I can't find now, but it was something like no more than 2 PSI (from 39PSI running) in a 30 second period. That was in regards to a regulator failure, but nonetheless, is probably a basic guideline for how long the system should maintain pressure. I've not seen that leakdown rate in a newer manual.
Does this link work? http://www.mediafire.com/download/i...Fuel_and_Emissions_Including_Driveability.pdf if it doesn't, use the link in my signature for the proper year manuals, and download them. PDF page 61 of the 1987 fuel and emissions manual shows the resistance values (approximate) for the coolant temp sensor, and I know a fair number of people have had issues with either the connector, or the CTS itself. I'd want to know with a dead cold engine (so it's approximately same temperature as it is outside) that the CTS is reading close to ambient temp.
The test was about a week ago the pump is 3 years old but i have seen them fail right out of the box. I already fixed the frayed and rubbed raw injector wires along with new injector connectors. I will mess with it monday being i got my lil one today and tomarrow is mothers day lol.
Stomis
Professional Amateur
Check for vacuum leaks, map sensor, stuck egr, and do the test on the ignition module.
I forgot more of the basics BTW...does the check engine light work? If so, do you have any stored codes? Google "GM OBD1 paperclip code checking" or something like that and you'll find out how to do it yourself. It's easy.
I have an alda cable i need to plug in. Not sure if check engine light works i was gonna swap a new bulb in to make sure. Thanks guys i will try to work on in monday and report back with results
