sharkman76

Hi All

Just Installed a 85 TPI Fuel pump in an 82 crossfire and the car has been running great for the last 3 days. Then on start up of day 4 GUSH!!! FUEL everywhere the front regulator diaphram blew out and leaked gas like crazy.

Now I am being told that I should have added an inline aftermarket type regulator to reduce the presure and that is why the stock daiphrams blew. That is totally not what I have been told at this point. Now I am confused.

Any Crossfire guys out there have done this mod? What an I doing wrong?

alswagg

You should have installed a TBI low pressure fuel pump instead. The TPI operate on high pressure, 45 to 60lbs. The cross fire is a TBI unit witch operates at about 16 to 20 lbs. This is why your regulator blew out. It will happen again if you continue to use the TPI pump with out regulating the fuel pressure down to at least 20 lbs. Al

MrForce

Was there any reason for the TPI pump?

Rob

sharkman76

SEE this why I am confused!!!

Before I did this up grade I did crossfire performance research alot of it. The TPI pump is a popular upgrade due to these cars always running lean. People on this forum and the guys at Dynamic Crossfire Soltuions www.crossfireinjection.net and the guys over at 3rd gen.org

They All recemonded this and no one said anything about the stock regulators not being able to handle it and adding an inline.

Do you guys know any crossfire guys that can help!!!!!!!!

texaswilkins

I did this mod to mine a couple of years ago. I put in a gauge so I could make sure I had the factory installed internal pressure regulator in the drivers side throttle body turned down to 15psi. That was the only external part I added. While it was was out I resealed everything in that throttle body. Several years into the process my throttle still has two positions, all the way up or all the way down and I have never had a bit of problem. Before the work the car started running out of fuel at around 85mph. Now it pulls hard till it runs out of horsepower at 110 or so. Gradually creeps up after that. The gentleman you spoke with in Arizona is the expert, listen to him.

Bill

terry82

a lot of us with the cross-fires have changed the fuel pumps with out a problem .i have not known of others that have had this problem because of changing the pump.i would replace the diaphram and try again .your car is how old and how many miles .it just could have been time to replace .lots of good help with the cross-fires on those forums they have been working on them for years.

sharkman76

That is what I thought was the case.

I ordered the pressure gauge set up from Arizona but they were out of the adjusting tool.

So I guess I have to make adjustments by pulling the drivers side injector tower making the adjustment then reinstalling it and checking the reading? Sound Correct?

Of corse I know I must reseal both throttle bodies and mop up a couple of gallons of gas.

As always forum members save the day!!!!!!!!!!

jdp6000

I have had the 85 pump for 4 years with no problems. But i did change the diaphrams and seals in both TBI's before the install.

Interesting its the front one. The regulator in the back one doesn't allow more then 13 psi to get through. You merely have a worn out diaphram. Easy fix. Replace all seals and diaphrams in both TBI's while you are at it. Its cheap.

Jim

Mr X

There's a lot of misinformation and nonsense I've seen over the years on this subject. First of all, you can install any pump, I've had the most powerful 255gph walbro for six years with no problems and I can still get the pressure go under 10psi just by adjusting the original regulator. Of course first you have to modify the regulator to make it adjustable and install the fuel pressure gauge to see your actual pressure. It takes the guesswork off.

Also only a few people seem to know that there is a 'gimmick' on the regulator when you adjust it: If you turn the adjustment screw too tight or too loose, the fuel pressure will actually go to the max. And that will cause leaks and symptoms like on this topic. Between those ends the regulator can be adjusted normally, so do not ever start the car after adjusting, just quickly test the pressure by turning the ignition on so that the pump activates for a few seconds and during that time read the pressure from the gauge. If the pressure is ok it's all set and you can start the car.

If you still keep having too high pressure then there's a problem somewhere like a pinched or blocked return line. That's the next thing to check.

V8Ranger

Mr. X, can you give us any details/pictures of the regulator mod?

Carl

Mr X

Sorry for the delay, I've been away. Don't have any pictures but basically you take the regulator bottom cover off and knock out the steel plug that probably still is on the cover. You now have a hole that you can access the screw that is under it. Then you have to grind a groove on the screw so I turn it with any flat screwdriver. So it's an easy mod.

I guess the most difficult part is to turn it from the bottom up when it's assembled and attached to the throttlebody. There isn't much room. So you either need a flexible tool for that or just take the regulator off every time for adjustment. I usually do that, but you have to check that there are no leaks when you start the engine. Taking it off multiple times sometimes ruins the gasket.

82BlueShark

Old thread... but thought I'd pass this along if someone uses the search thread.

You might not need to cut the harness to adapt it to the TPI pump if your harness is in good shape and there is no drop in voltage. Why cut things up if you don't need to, right? You may be able to repin to the late model connector.

Check the terminals of the TBI pump- they may be the same as the ones used on the TPI pump, sans the plastic connector.

If so, all you need to do is to use the end of a small safety pin to depress the retaining clip on each terminal (inside the connector) and then slide it out the back of the connector. You can buy a pigtail connector/repair kit for the TPI pump and then slide the old terminals into the late model connector. And then you are done!

Zip Corvettes

Ok so I have heard allot of people talking about this and WHY. Why do you need a pump that is capable of supplying fuel at 60 psi when your setup runs at 15 psi. If you regulate it down back down to 15psi what have you achieved. If the injector has 13 psi with the factory pump or a 60 psi pump what have you accomplished. So if you push more psi you effectively create a larger injector, but it everywhere in the RPM band, if you are not re-calibrating your prom why would you want to do this? It absolutely makes no sense from a performance stand point or a drivability stand point. What would make sense is to have a pump that can supply the needed volume at 15 psi at all times.

Buccaneer

Hi Guys, first off fuel pumps are not rated in psi, they are rated in either gph or lph and will support up to ex-amount of psi regulated. A stock CFI motor only needs to be set at 13psi (this is the recommended GM setting, from 9-13) on the (regulator) to run properly. This has been done and verified and I can not tell you how many times over and over again with a 85-87 pump v.s a stock pump. The issue with the stock pump is that they are not created equal and may or may not flow the proper (volume) to get the increased psi that you want or required to make the motor run properly...hence the other 85-87 pump that does a great job. There should be no reason really to set the FP to 14psi or higher on a stock motor since the stock ECM will not know what to do with it anyway since the VE table is set to support a max of 13psi with a stock injector.

Now with that said, it is my opinion that you definitely should replace the bladders in both TBs when you replace the pump. In a lot of cases, the owner has absolutely no idea how old the bladders are and more than likely they need to be replaced for good measure. I have been running that pump with the pressure set to 24psi for my 383 for at least six years now without issue. Also, with that said I can tell you that at 35psi plus it will blow the bladders, ask me how I know that and it is NOT recommended to set the FP that high without going to an external regulator and using blank off plates on your TBs running a parallel plumb system.

Back to the FPR settings... So, like I mentioned you only need 13psi for a stock motor and No, you can't re-calibrate your stock 82 ECM properly since it was never fully hacked like the 84 ECM. If the stock 82 pump can support the volume demand of a regulated 13psi then you are golden. If not, you will have to go another route or just keep trying to find a pump that will perform.

BTW...The swap from the stock pump to the 85-87 IS very simple, only two wires.

Kipring

Ditto, did the same thing and ran it for two years before leaping onto the LS swap bandwagon. Never had any issues, but again I did what Jim did. I was worried about the older parts and replaced the diaphragms and seals. I also cleaned the injectors thoroughly. The engine never ran better (albeit when I got her, she had been sitting for eight years )

Zip Corvettes

You realize that pressure is not that important but flow is. The whole idea is that if your system was designed to have 13psi then you need to have the flow that will supply 13psi at all times. That flow is different then the flow at 60psi of pressure. For example you don't water your flowers with a pressure washer. What pressure can do besides blow the seals out that were not designed for that much is it changes the characteristics of your injector. It changes how much is flows and if the ECU does not know it you will chase issues. That is not how it works, now if you have a pressure regulator that can take 60 psi or more down to 13 psi, then you can run whatever pump you want, but most regulators only work on a percentage.

texaswilkins

Complain about it if you want but my 82 used to run out of fuel around 85 mph and would pull gently up to speed after that. Now with the higher fuel pressure it runs out of horsepower around 110 mph and pulls gently after that. High RPM driving seems more predictable now too. While I had the TB's off I rebuilt them and have not had a problem yet. 305000 miles on the car and a couple of autocross trophies make me think its doing pretty well. If you are never going to use the top end of your tach it's probably not worth your time.

Bill

Zip Corvettes

I'm not complaining, what I am saying is allot of people who don't understand the science behind it are just randomly bolting on fuel pumps they don't need to. So your original pump was probably done to begin with. Doesn't mean a new one would not have fixed your issue. If you have a built engine that also means your requirements have changed. If you have stock injectors, you are probably lean. My point is you don't just blindly bolt fuel parts on if you don't know what they are doing or going to do. There is a real science behind it and GM doesn't do it like that either. Like I said you don't water flowers with a pressure washer. We just had someone call us asking if they could bolt in a 85 pump in there 82 from reading this post. The answer is...... It is ill advised. Like I said earlier you need to invest is a really good regulator that will be capable of controlling the flow if you are going to do that, the stock one will not.

billschroeder5842

I might recommend you take you question over to the C4 board as your car is more TPI than crossfire now.

Zip Corvettes

Buy a pump for your 82, that should make it easy.