Oh, that sucks, need to sell my set up, thanks for letting me know

 

There's a possibility that the retro-fit won't depreciate the value of your '82. But, I've been closely watching them selling on the Internet for three years and the modified 1982 engines almost always drag the car's value down. It's your personal preference since you own it, but be aware of the ruthless market economics of your decision that will likely disappoint.

X-fires can be made to run superbly, as mine does just that - but not by traditional carb specialist shops/hobbyists who haven't deep-dived the relatively simple/primitive integrated system.

Good luck -

Dave

 

Thanks for your input on the matter, I understand is usually not a good idea to change or heavily modify a car, scars alot of people away from giving you the true value of your car, but, I've had my vette up for sale for a while now, the few calls I have gotten on it, as soon as they hear it's a crossfire injection, they are no longer interested in it due to the reputation of them, if it was running in good shape it could sway them a little bit, but mine is having fuel pressure issues that, I have done everything to it to get the pressure up, but it's not happening & plus finding a mechanic who wants to take on it, it's becoming a problem

 

Be certain to check the tight seal and confirm the fuel rating (emphasis here) of the little black hose that connects the pump to the sender. It really needs hose clamps. My aftermarket pump didn't have small hose clamps and included a non-fuel tolerant hose that prematurely (5 weeks) softened/degraded so that fuel leaked past it under pressure despite no outward appearance of a problem. Seems this is a common issue and easy to overcome. Actually, someone had posted this easy to overlook fuel pressure causal part, so I was/am grateful for this sharing venue.

 

Yes, I had heard of that issue, I replaced that hose & it's clamped down, I'm only getting 10psi as it is now, one guy told me to clamp down the return line hose to see if the pressure would change, it went from 10psi to 50psi when I did that, he said for some reason the fuel was getting by my regulator, he's sending me another one but I suspect that's not gonna change anything, I've rebuilt both tbi's so as of right now, I'm just frustrated beyond belief cause there's nothing else to replace or check, ugh

 

I'm actually feeling your pain, walking in your shoes. You probably considered in your decision for an `82 the progressive refinement/technology of that last year, so its a shame you're having these problems. You know how well the system performs when properly maintained as stock/unmolested. There are only a handful of sensors and the ECM is normally pretty reliable. The fuel delivery system, while quite innovative by `82 standards, is fairly straightforward. The automotive engineers that I work with laugh at how basic the system is compared to today's vehicles. The regulator issue you reference is an interesting twist. So, my suggestion is that you reach out to Dub via a PM. The guy is sharp. Tell him what's already been done. He knows the system in his sleep, and is a good guy.

Dave

 

Is his name just Dub or ?

 

If I remember correctly... the later 85 & up TPI fuel pumps have a different size outlet than the OEM 82 Vette fuel pumps.

The outlet on the 85 pump has a smaller diameter. You can slide the slightly smaller size hose over the OE sender's hard line- it will stretch a little. But if you run the OEM hose to the fuel pump...

You could be losing fuel there.

At this point, if you have reassembled the TBs properly to include setting (of not altering) the FPR... that's the only thing I can think of. Aside from maybe not enough volts at the fuel pump. Or perhaps you just have a bad pump.

I'd go on the assumption your FPR is correct and you have enough current at the pump.

You may have to slide the sender and pump assembly out to check for voltage though.


Really... if the lines aren't leaking, your filter is good, and your TBs were reassembled property... perhaps the only place to look again is in the tank.

 

Ok, here's the story on it, I put a pressure gauge on it, it reads 10psi, I rebuild both tb, no change, I installed a new 82 pump, still no change, install a 85 pump, still no change, I drain the fuel from tank, find alot of debris it it, completely clean tank, replace filter, refill gas tank, still no change, replace all the rubber fuel lines, front and rear, no change, clamp off the return line, pressure jumps to 50psi, told somehow the fuel is getting by the fpr somehow, spring has enough tension on it to where if I disassemble the fpr, u have to hold it really tight or it will get away from u, so I'm not sure what else I can do, guy is sending me his old, known working fpr, but at this point, I have no faith in this being the problem to my issue

 

Where did you measure the fuel pressure- did you measure it with a gauge between the front and rear TB?

Also... you mention debris in the tank. Sounds like you replaced the filter sock in the tank but did you replace the filter in the line on the frame just behind the passenger front tire?

If you clamp the return line- yes- you will see pressure jump because it's clamped and serving as a restriction. That's not really a good way to diagnose the problem other than to say the line can take pressure.

Also- did you use the correct diaphragm from the rebuild kit? One is for the front and the other is for the rear. You won't develop the right pressure if the spring was seated for one- and you put the other in.

I'm not sure how you could have fuel getting around the regulator. The regulator either works or it doesn't.

I think you aren't getting enough pressure because something isn't working the way it should- it's either mechanical (clogged filter / improper set regulator) or electrical.

My guess is mechanical.


I think it is one of three things- or a combination
1.) your fuel filter is plugged
2.) the pressure regulator isn't assembled properly
3.) you aren't getting enough voltage to the pump

There's not a lot left after those.

 

If it were me... and the car was stock... I'd have the tamper plugs knocked out and bushings put in on the throttle shafts.

I'd do it myself or get someone to set the base idle and to balance the TBs.

I wouldn't swap the system out. It will create more headaches than one is solving for. CFI actually does a decent job of wringing out every drop of potential for the stock configuration. The cam and heads are what they are- the cam doesn't have a lot of lift at .410"IN / .423"EX.

The L48 and L81 cams have less lift while the L82 comes in around .450"IN / .460"EX. I bring up the L82 because that engine was rated to have only 30hp more- yet it had more lift than the L83. Those three engines are your stock headed, carb'ed comparison motors.

Putting a carb on it will require a small carb and a you'll need a dual plane intake. There is 0 performance gain and perhaps a step back because carbs don't have the ability to compensate for environmental conditions the way EFI can.

The cars will run beautifully if maintained. That's true of just about any car to be honest.


Again... I bring this up because I think your problem is going to cost less than $200 yet swapping the car over will cost almost $1k.


Shopping list
Carb- $400
Intake- $150
Distributor- $150
Coil- $50
Gaskets- $20
Air filter- $50
Throttle cable & bracket- $100 (yes- you will need those)
700R4 lock-up kit- $50 (if you use a toggle switch)
Misc supplies- $30
$1,000 total spend easy...

You can get the bushing service for less than $200. Set your idle and balance your TBs yourself- and you're done. It'll run a lot better with those small procedures once you get your fueling worked out.

 

All a regulator really does is block the flow of fuel until a certain pressure is reached then it opens to allow just enough fuel to flow so the pressure is maintained. In other words, it's just a controlled 13psi leak.

So, I'll stand by what I told him before and that was to clamp the return line and check for a pressure increase above the required pressure. His test proved pump is more than capable of creating the required pressure and that the regulator is not doing it's job by allowing return fuel to flow at too low a pressure.

There would be no return fuel flowing if the regulator was actually set for 13psi and he is seeing 10psi of pressure. So, clamping the fuel line in this case would have no effect on the fuel pressure. Once again, the test proved it was the regulator.

Things like a plugged filter or restriction in the feed line only come into play at WOT when there isn't enough fuel flow to feed the engine. This is when you'd see the pressure drop while running WOT. If this is happening, the regulator would actually be blocking off all return fuel as soon as you see the pressure start to drop. If you did clamp the return line, you'd see no change in the fuel pressure.

This is the problem with posting the same issue multiple times. You get multiple answers that have already been ruled out in the last thread which is just confusing.

 

And you can get bushing kits for about $50 on Ebay and likely on Amazon too but I've never looked there.

 

No disagreement about that.

And if the regulator wasn't assembled correctly- i.e. the wrong diaphragm used or not enough tension on the spring- that's exactly what would happen. Lines are good- it's not that. Something isn't allowing it to build pressure. Either there is an obstruction (possibly not getting enough fuel to where he's measured his PSI)- or not enough of one (regulator not working).

I would normally agree- but when the OP talks about a tank full of junk- he might have debris that has slipped past the sock. I'm willing to believe that if that filter wasn't changed out than it is chock full of stuff. That could add to /exacerbate the problem. He might have so much junk in it that even running in the cruise or idle KPAs could be a challenge. Just depends on how much stuff is in it. He could have enough junk that its already dropping. But that would only be PART of the problem. I still think it's his regulator that would be the long pole in the tent.

Not sure everything has been ruled out. Otherwise... he'd have his problem identified.

Not saying things to stir the pot or be obstinate... just trying to be helpful. Something isn't adding up.

Unfortunately, none of us can look over his car with him... let alone see if he missed something or is doing something wrong. I sense that he's just missing it. He's really, really close though...

I still think his biggest problem is the regulator. I think the diaphragms were swapped.

Clogged filter won't help either though. Regardless of being at WOT or idle.



Add the two together and you have a recipe for a lack of functionality.

 

The CFI system is very basic and relatively simple once you understand what it needs to run properly. Swapping to carb is the last thing you want to do unless you are looking for some serious horse power.

 

Thats what is getting to me, I've done what is needed to boost the psi on this thing, other than buying another rebulit kit for the bladder for the fpr, assuming the one I got is bad, there's nothing else to do, but the other thing is, it's the same psi as before I started all this, this should be simple due to it being a basic system, the only other thing I can think it would be cause nothing has changed is the tb, divers side, w/the fpr in it is defective, I only know of one place other than ebay to get one is through a salvage yard near me that specializes in corvettes, he's not going to just sell one tb, if I have to go that route, I will switch to carb, I'm just throwing money at it at this point & I only have so much to do this with

 

Did you use the diaphragm on the left for the driver's side injector tower?

 

If the filter was so badly plugged that it can't make 13psi then he certainly wouldn't see 50psi when he pinches the return line. It's the regulator plain and simple. No other explanation makes sense except an internal leak that is bypassing the regulator which once again is the regulator.

 

Thats the one with the metal plunger, used that one on the driverside

 

Did you knock out the tamper plug? Could you have mis-adjusted the set screw as you reassembled it?? You mentioned it was hard to get back together.

Another thought maybe to knock the tamper plug out if you didn't do that the last time and back the screw down. That will take pressure off of the spring as you reassemble it. Then, once the regulator pod is back together, you can tighten the pressure screw back down. Then confirm it with your pressure gauge.


Also... not sure if you actually get to 50psi by crimping the line. I don't think you can create more PSI than your pump would allow for. I say that because I ran the OEM spring and pump at one time and the most I could ever get was 14 PSI- and I had the screw as tight as it would go.

I think getting another rebuild kit would be the way to go. Just start over with less tension on the regulator and then increase it to the desired FP.

Something didn't go back together correctly.