Alright Fellow ElCaminoers.....

I was finally able to start up my TPI project. After blowing fuel line after fuel line on the return side, I finally got them all taken care of. The car started up perfectly on the first try. 8) Idled just perfectly. 8-) I didn't have the radiator and everything hooked up, so, I only let it run for about 15 seconds. The next day, I had everything installed, and fired it up. After idling for about 3 minutes, I heard some wierd whining sound, then, it started puffing out white smoke that smelled like gasoline. After shutting it down, I pulled the vacuum line off of the brand new fuel pressure regulator diaphram, and audjustable cap, and gasoline was running out of it, and into the plennum, down through the runners, and into the engine. OK. I take the cap off, and replace the torn fuel pressure regulator with a brand new one, use the stock cap instead of the adjustable one, and fire it up. It ran for about 6 minutes, then, here comes the white smoke again :x :mad: :cry: :evil: !!! After shutting it down, and pulling the fuel pressure regulator vacuum line, it is filled with fuel again... I haven't taken it apart again, because, I already know what is lying beneath.

Why is this happening??? Why am I continuously blowing up the diaphram on the fuel pressure regulators? Aren't these things supposed to stand up to high pressure? I am running an inline Holley fuel pump, but, it is nothing special. Anyone else had this problem? Can I run an external fuel pressure regulator with the TPI? Any help would be appreciated...

Also... Something is running down my battery... I think the culprit is the fuel pump. Whenever I unplug the battery, I can hear the fuel lines depressruize (<-spelling?). I have the fuel pump hooked up to the ecu like it is supposed to be. Any one else had this problem? Besides a toggle switch, what was the cure? Isn't the computer supposed to cut power from the fuel pump when the key is cut off?

Thanks in advance...

OK. Just spoke with the folks at tacreationsusa.com. It made sense what they said. Possibly the issue could be with my return line. Either there is a bottle-neck in it, or I would have to run a bigger line. His notion was that a restricted return line would build up pressure at the regulator, and bust the diaphram.

Those out ther with fuel injected El Caminoes... Did you use your stock return lines and beef up the spots with the week rubber tubing, or did you have to run a larger diameter return line all the way to the fuel tank? Did you run into any bottle-necks along the way? If so, where?

thanks...

I put in all new lines: feed and return. Braid steel -8 lines (about 3/8") in the bay and at the tank and hard lines along the frame. The original fuel line was on the wrong side and my El had sat for a few years and I didn't know what had built up in the line. I was told that I didn't need that big of a return line but when I was running it, it just seemed easier to run all the same size for getting connectors etc.

It does sound like it could be a problem with the return line now that you have said it. I don't think if I would have thought of that.

Well, I have an extra IROC at the house that I am using for parts for this El Camino project. I will probably see if I can use the feed lines from that for the return lines for my El Camino. If that is too restrictive, I will try a gargen hose... :lol:

What are you using as your return line? When I installed my TPI I used the line on the drivers side that went to the vapor canister from the fuel tank(my truck only had a single line on the passenger side to the factory fuel pump and no return line as well as the vapor line on the drivers side) for the return line. Upon startup with a fuel pressure gauge attached to it the pressure immediately shot up to 80+ PSI. Turns out that the vapor line has a very small orifice at the fuel tank side. After I drilled it out the line was capable of handling the return fuel volume without a problem.

My truck is an 82 model.

Well, that makes sense too. The last line that blew and was replaced was the little rubber line that actually returned fuel to the sending unit at the tank.

I am using the vapor line that came from the charcoal cannister. I replaced all of the rubber bits with steel braided line of the same size that is being used in the feed line.

Those darn fuel pressure sending units aren't cheap either. I bought my first kit from the Chevy dealer. $190.00!!! 8O 8O 8O

After that blew, I replaced the spring loaded diaphram with one from the local parts store... $23.00. I never thought about drilling out the orifice at the sending unit to enlargen the return piece. It sounds allot cheaper than buying another fuel pressure sending unit...

Thanks for all of the responses. Keep them coming. I will be under the car again this weekend... Every bit of advice will help...

Thanks again...

If you are using the vapor line for return at the tank there is a restriction (the hole in mine was about 1/64th of an inch in diameter, way to small for fuel to flow) that has to be drilled out in the sending unit that is under a metal plate.

Can you put a fuel pressure gauge on it to verify pressure?

You could also get a sending unit from a 86-87 model that had the injected v6 which will allow you to run a intank pump and has all the fittings, feed, return, and vapor to canister.

Hope this helps

Alright... I think the problem licked :P :P ... Thanks for all of your input. It seems that it was in fact the tiny hole in the vapor return part of the sending unit. I pulled the unit out, drilled out the spot weld in the cover, removed the cover, drilled out the little hole, and spot welded the cover back on. After replacing the fuel pressure regulator, I fired it up... It fired right up, and idled, reved, and idled again just perfectly...
Thanks for all of your help, and input!!!

One more question though :? ....
With the excessive amount of fuel running into the engine through the intake runners before the fuel pressure regulator situation was fixed, is it possible that some fuel may have gotten into my oil? Before the replacement, the car was running so righ that it was spitting gobs and gobs of raw fuel out of the tail pipe. Now, my oil level has risen significantly, and the oil also smells like fuel... There is no doubt that there is some fuel in the oil, but, could the faulty fuel pressure regulator have caused it, or could there possibly be another problem?

Thanks in advance...

If the oil level actually went up, get the oil changed asap. With that much fuel vapor in the oil it can ignite and cause damage if it explodes. Hopefully this is not a new engine as you may have trouble getting the rings to seal from the fuel washing down the cylinder walls. If it is a old engine everything should be ok after the oil/fuel is drained from the pan. This is another reason why I always put a fuel pressure gauge on a FI conversion before I fire it the first time. Have fun with the TPI.

Well, this is, in fact a brand new engine. I purchased it from my local GM dealership... The engine has only idled for about 10 minutes since new I have only driven it in and out of the workshop. Hopefully, I have not caused any harm...
Thanks for the input, I will change the oil immediately...

I have a separate question about this conversion. I will post a new topic in this forum called "C5 Injectors?" Check it out. I can always use some advise...

Did the engine ship allready broken in, or did it have break-in procedures that came with it?

No, it wasn't already broken in. It came with procedures...

That's what I thought. Just make sure to change that oil before running it any longer. Then follow the procedures as close as you can.

Will do.... Thanks again man...

While I have your attention, check out my next post...

http://www.elcaminocentral.com/modules.php?name=Forums&file=viewtopic&p=57862#57862