Q: Rebuild/Replace TBI Fuel Pressure Regulator

[LA2SD]

Greetings all -

I did a search and couldn't find what I was looking for. Anyway, I'd like to rebuild and/or replace the fuel pressure regulator diaphragm, and possibly the spring, on a 220 TBI unit.

I found a kit made by standard auto that includes the spring and diaphragm for about $26; and a kit made by Delphi that includes the diaphragm, but not the spring, for $68.

The Delphi diaphragm is made of nitrile, which is "supposed" to be more resistant to ethanol, but it's almost triple the price.

Anyone have experience with either kit? Does the regulator spring wear out enough to need replacing? It's weird that one kit includes the spring, but the other doesn't.

Also, the shop manual says not to pull apart the fuel pressure regulator due to possible leakage when putting it back together. And to replace the regulator as a whole.

Thoughts?

Thanks in advance.

 

[dusterbd13]

Ive used the standard kit in four tbi units now with no issues

 

[evilunclegrimace]

If you do pull it apart you need to be careful reassembling it. Make sure that the diaphragm is showing on all 4 sides before you tighten the screws down. There are a few companies that make adjustable regulators that can help with drive ability issues caused by regulator springs that are on the lower end of the 9-13 psi range

 

[thinger2]

Welcome to the world of TBI nonsence.
Get the kit with the spring.
Just keep in mind that most of the Youtube vids about TBI rebuilds are full of ****.
Your kit will come with a bunch of crap parts that do not apply to the 220.
They are kind of generic kits.
Pay very, very close attention when you take it apart.
Take pictures, write notes whatever.
It really is pretty easy. Just Do Not Get Distracted!
The injectors have these tiny just insanely small screens you need to replace.
They like to pop off and you will never see them again.
I replace them but sticking my head in a box so if they pop off i can find them again.
Dont try to seal the injectors by screwing down the "top plate" to seal them.
You can bend the top plate
put a tiny, tiny, very tiny bit of vaseline on the seals and push them in
And, most of the kits i have seen, recommend a gm thread sealer that crossreferences to a "red" locktite.
Do not use red loctite
You will never get that thing off again.
Use the blue on the top plate and be very gentle when you do it.
Dont use the top plate to pull the injectors into place.
You can bend it
Seat the injectors with a little kinda twisting motion.
The top plate just holds them in.
Its all really easy to do and well worth doing.
If you run into any problems or questions ask away .

 

[LA2SD]

Thanks for the response Duster. Looks like I'll be going with the Standard Auto rebuild kit.

I'm looking to keep the stock fuel pressure regulator, and that kit checks all the boxes. I'm running a stock 350 5.7L.

Appreciate the detailed responses Grimace and Thinger. I've got the factory shop manual, but it leaves out some of the stuff you all mentioned. I'm aiming to get this done this week if I can get the parts.

I was hoping to replace the intake manifold at the same time (big leak where the heater hose coupling screws into the manifold), but the stuff from edelbrock and holley seem to have some issues with their castings.

Would you guys happen to have any recommendations for a stock style intake manifold? I wouldn't mind hitting the wrecking yard. But I don't want to spend the time pulling manifolds only to find out they're all junk. Might not have a choice though...

 

[thinger2]

Is your leak at the radiator hose where it goes into the intake at the water neck fitting? Send some pictures of exactly where this is.
Dont go buy a shitpot of parts untill
you post..
We may be wrong, but sometimes we are right

 

[LA2SD]

I'll snap a few pics this week.

The leak is at the back of the engine, right next to the distributor. There's a fitting that screws into the manifold, next to the distributor, and it feeds coolant to a hose that runs through the heater core inside the cab.

I replaced that fitting last year when I replaced the intake manifold gaskets. It was practically frozen in place. Lots of liquid wrench, a breaker bar, and the handle from my floor jack, loosened it up.

But the threads didn't look all that great. Cleaned it up the best I could, and used PTFE paste when I installed the new fitting. The truck runs cool, but the temp gauge fluctuated too much for my liking. Looked for a leak, and found a small puddle of oil and coolant near that fitting.

 

[dusterbd13]

Those are notorious for leaking. However, i can't remember seeing many of them with bad threads. Bad quick connectors are pretty much guaranteed though.

I ran the edelbrock tbi intake on the 94 tbi engine in my 64 el camino. It was not a direct replacement for the factory intake i removed. Im also not sure there were any gains with it. But there were no quality or casting issues either.

If you were closer, i think i still have a couple random tbi intakes in storage.....

 

[LA2SD]

So, the threads weren't exactly bad, like they were tapped incorrectly at the factory. There was just a lot of gunk and what looked like corrosion in the manifold.

The quick connect had been replaced with a solid nipple by the PO, so I just replaced it with the same. I'll see if I can snap a good pic of the nipple since I discovered the leak. It looks the the coolant flushed all the thread sealant out of the threads.

Thanks for the offer. Shipping is a killer.

I was looking at the edelbrock # 3704, because it's the closest thing I could find to stock, without having to install a cam or new heads. But it's pricey, and I would have to tap the front accessory mount. I also read reviews about the cable and coil bracket mounts being off.

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[thinger2]

I forgot to mention on the TBI rebuild kit, some of them come with a couple of screws that dont seem to belong anywhere.
Thoses screws are used to pull the fuel pressure diaphragm into place temporarily while you get it all aligned.
then you take them out and use the regular screws to hold it down.
When you get it all back together, turn the key on and look for leaks.
If it leaks or dribbles gas anywhere, you have a seal not seated correctly or an injector not seated all the way.
The kit has a couple of very thin washers that fit into the top of the injector bore.
These are "corrective washers" used to re establish a sealing surface for the upper injector o ring.
Sometimes it needs them, sometimes it just makes that o ring leak like crazy.
If you put that washer ring in and fuel blows past that o ring?
Take those washers out and forget about them.
I usually build them, run them and check for leaks, and then take out one screw at a time and put the blue locktite on.
And I never use a ratchet on a TBI. Just a nut driver with a socket so I dont warp the parts