JoeBobJr

I have ab 89 camaro 305 TBI installed in an 85 Chevrolet C10 pickup. I believe my TBI is getting way too much fuel pressure. I haven't messed with the regulator but I have pulled it all apart to sand blast and clean up a while back. I haven't had much time to mess with the engine. I noticed at idle its putting out way too much fuel. I put a 75psi 89 f150 inline pump and I think my regulation is not right. Where do I install a gauge to find out how much pressure the TBI is getting? If i install a gauge before it goes into the TBI how do I know what its getting inside the TBI? I do understand I can install my fuel pressure gauge anywhere in the line coming from the tank to see the pressure but I already know what pressure the pump puts out. I'm wanting to know what the TBI is getting so I that I can drill out my pod and start adjusting the regulator to 14psi or whatever it needs to be set at. EDITED: On another note I have 2.8L v6 injectors installed at the moment. I'm completely broke and it's what I had sitting around when I noticed one of my injectors wasn't pulsing at all. I know it's not the right injectors but that still doesn't explain why the injectors are spraying so much fuel at idle. It's running extremely rich. I tried installing 350 injectors into the pod about a week ago and it was really spraying too much gas. So much gas that it was flooding out to the point it wouldn't even start period. It would soak the spark plugs in gas. I really had no clue what was going on till a friend came over and seen straight off it was spraying way too much fuel. He said it has to be getting way too much fuel pressure. So I'm hoping you guys can help me get the pressure set correctly so I can get my truck running right again.

Ronny

place reg and gauge after the injectors. check out z28boy site. use a non liquid gauge. liquid will not read right unless cold start....

JoeBobJr

I've seen the site but that's not what I'm asking. I want to know the pressure that my actual TBI is getting. The regulator that is built into the TBI unit. I don't have the money to spend on an external regulator to do it that way. I know you can adjust the factory regulators but after I adjust how do I know my fuel pressure so I know I'm getting around 14-18psi?

one92rs

buy a gauge adaptor to put inline with the supply line going to the tbi. did you remove the original pump before putting an inline one? or just add it to it? earls makes an adaptor for a gauge that will plug in at the line. there are some adaptors on ebay as well.

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JoeBobJr

The 85 C10 came with a carb. The only way I could have ran an in tank pump was to replace the sending unit and maybe the tank I really didn't research it that good. I just figured inline would be the fastest easiest way so that's what I did.

UnderCover89TBI

Liquid wont read right? Y is that?

one92rs

because as the iquid heats up it changes the pressure reading due to the air bubble in the gauge. but a non liquid gauge will still have the little bit of movement while reading the pressure and tend to read a lil higher.

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UnderCover89TBI

hmm. true. did not think of that. thank you.

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Look's good from far, but far from good looking!

Ronny

TurboCity may have the adapter as well. Stock FP is 12-13 lbs.

Napster134

So thats the real reason why that happens huh lol Yup thats what the liquid ones do! just read them cold lol

UnderCover89TBI

Yeah I want a gauge inside the car so i'll have to figure out something for that.

SKFengineer

It sounds like you have way too much fuel pump in your system but to answer your questions. First put the fuel pressure gauge somewhere between the fuel pump and the throttle body, most of us put the gauge right at the inlet to the throttle body.

During your rebuild you may have messed up something with the fuel pressure regulator however I'm wondering if since you have such a large pump that the return line leaving the regulator going back to the tank is too small and adding to the restriction, therefore additionally increasing your fuel pressure beyond what the regulator can control. As many on here have said, 12-14 psi is what works best. You can find some additional information on a site called CFMtech.com, they are mostly for boats and the TBI units on trucks but the information they have applies here too.

Lastly someone noted a fuel pressure gauge in the car, I have this on my TPI car and it's pretty easy to do but costs a little bit of money, 100 bucks plus... Autometer makes a electric. sender for under the hood and then sends a signal to a box in the car which you hook up to a gauge. Don't run fuel into the car it's a fire hazard and most inspection stations will fail your car. I've had the a 0-100 psi electric fuel pressure gauge in my car for about five years and it works great.

My two cents.

UnderCover89TBI

sweet ill look into that thank you

gregs78cam

I agree, happened in my truck. I used an aftermarket fuel pump that pushed so much fuel the factory TBI regulator could not return the fuel fast enough. It ran real rich. Put in stock fuel pump, ran great.

Also your ECM needs to have the injector constant right in the chip for the actual fuel flow @ whatever PSI you set it to.

Now, an '85 C10 should? have the same gas tank as my '74 K10??? Find a pull-a-part and get a 90's van fuel pump assembly, shorten the pick up tube above the pump by about an inch and stuff in there. Works great for me.

thomas1976

FWIW, TPI and TBI fuel lines are the same, except the lengt and shape of the lines going over the engine to the TB.

the solitaire

Not sure if it was mentioned before, but the factory regulator will not go far beyond 15 PSI if I remember correcty (picked up something along those lines in the stickies)

18 PSI and stock injectors would allow for 300'ish HP from the 305

UnderCover89TBI

i just installed a 255 lph in my car its running rich but only because I have teh fuel pressure to nearly 20 to get it to run decent without bogging down at high rpm's. Im getting the ebl soon hopefully I can cut a few psi out of it and with that tune her up real good

Ronny

top down solutions sells a spring that is one step stronger than stock. Like $12 plus ship.

regardless of what you do you may have seriously over fueled with that pump. There may not be a fix in sight. Even a VAFPR may not help. Was not a smaller inline pump available? I thought Holley had one for carb to TBI conversions at 22 lbs FP?

UnderCover89TBI

i didnt even realize he put that pump on there. that could be a problem

one92rs

75psi that is way to much fuel flow for a stock tbi regulator.

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SKFengineer

75psi is too much fuel for a TPI setup too.