Pictures of progress
- Thread starter 351 celi
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Flooding is fixed. I had fuel on the bottom side of the power valve, so I replaced it and the gasket. I also found a torn gasket beneath the booster assembly that I replaced with a good used one, seems to be good now. Next on the super to do list is #45 plugs, rejet, water injection, and drill the PVCR if necessary. After that and some odds and ends it will be bump it up to ten psi and maybe 2 more degrees of advance. She pulls good now at 7 psi, but lean, so no more boosting until rejet, injection and PV work.
She's rejetted, no more lean at cruise or boost, but I still need to do a long boost run at higher speed to see if my PVCR need to be drilled out. I would like it richer under boost, she is mid 12s to mid 13s, so likely will verify PV is opening first naturally asperated (it should be obvious when running no boost), and then drill the PVCR to .0625 first, hopefully get me to mid 11s-12s for A/F. Slowly making progress.
Well, I drilled my PVCR to .0625", now we are rich, actually more than I wish but atleast it is safe now, and also have one step colder plugs. I now have the issue if I am in boost longer than 5 to 7 seconds, my bowl runs out of fuel, so it appears my mechanical pump cannot keep up, even though it is boost referenced. I'm actually surprised this is occuring at only 7 psi, but looks like it is time to install the modified regulator, inline efi pump, and return line.
Do you have a fuel pressure gauge in the cabin with you? Does your fuel pressure increase with the manifold pressure?
To me, it sounds as if your boost pressure equals your fuel pressure. And we all know what happens when you try to push fluid into an area or equal or greater pressure.
Given the last post was a month ago - I suspect you have it figured out by now.
To me, it sounds as if your boost pressure equals your fuel pressure. And we all know what happens when you try to push fluid into an area or equal or greater pressure.
Given the last post was a month ago - I suspect you have it figured out by now.
Turbo_B":1mrt0wf8 said:
When I was running my old setup this is the EXACT same problem I was having. my fuel pressure wasn't rising like it should so at 7 psi I would get a nasty lean pop. I finally bought a pump and a new regulator and then my tranny went. I never got to see the 10 pounds my wastegate was set at
I Will this time thoughI do not have an in-cabin gauge, but tested the operation of the boost referenced port on the fuel pump while the engine was running with my air compressor and a precision regulator. For each pound I dialed on the gauge, my fuel pressure at the carb went up one psi, so it is assumed it is working with the signal from the manifold. I am going to go ahead and install the efi inline pump and modified fuel regulator for boost reference. My newest problem is not being able to turn up the boost to 10 psi. I am spacing the wastegate actuator with washers as shims, and this shows it now takes 10 psi to open the wastegate b/c of the addition spring tension, but while driving it, I still only have 7 psi. I have a feeling it is caused by a restriction due to the low profile carb hat. I plan to hook up a boost gauge at the compressor and compare readings to the manifold pressure. I have added an additional 2 degrees of mechanical advance, and leaned it out under boost to a safe level, from low 10s previously to 11s/ low 12s now, it really helped.
UPDATE: Been really busy! New classic inlines carb hat allows alot more boost, but it does not seal worth crap, and last night blew a gasket out the side of the carb. I modified the manifold for direct mount 2V, upgraded the fuel system with a boost referenced carter superstrip for a 350 chevy and new AN SS feed lines, so no more fueling issues, I highly recommend it since it is simple, no need for an electric pump, regulator and return line. Car feels pretty impressive for a stock 250 with small turbo. I am dropping 4 psi across the intercooler, I need better couplings and clamps. Last night I bypassed the intercooler and saw 14-15 psi at the manifold prior to the gasket blowing out. I also upgraded my oil feed line to AN4 with banjo fittings and added the water cooling to the turbo and heat wrapped the downpipe, and added 302 springs in order to increase my RPM range, as I was experiencing valve float previously at 4200RPM at only 7 psi. Really 10 psi is the plan, but 4 psi drop is unacceptable.
I need to do some tranny work to the C4, and also either buy new couplings and clamps or get someone who can weld aluminum to weld a majority of the pipes up. I am really disappointed with the fitment of the carb hat.
I need to do some tranny work to the C4, and also either buy new couplings and clamps or get someone who can weld aluminum to weld a majority of the pipes up. I am really disappointed with the fitment of the carb hat.
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