[HWYSTR455]

Just to throw it out there, the internal regulators in the FIT TBs are known to have issues. Actually, have heard some have issues with the Sniper ones too.


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[JLMounce]

Originally Posted by HWYSTR455

Just to throw it out there, the internal regulators in the FIT TBs are known to have issues. Actually, have heard some have issues with the Sniper ones too.


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I have a genuine Bosch 4 bar regulator that should be arriving later today. I'm going to throw that in today since I have a bit of time and see what happens. If it has a positive effect on the fuel pressure situation, I can put some light mileage on the car to burn up some fuel, then replace the fuel pump.

Both the FiTech and the Snipers come with offshore generic FPR's (sensors in general). When the time comes to replace sensors, definitely better to get genuine stuff.

AC Delco for the CTS
Bosch for the FPR and WBo2

[Formulajones]

I didn't know you had one of those internal regulators.

The stealth snipers don't come with them and pretty sure now the new renditions of the regular snipers have eliminated them also. They were almost always a problem

[JLMounce]

Correct, all FiTech's with exception of the Classic series with divorced ECU's have internal regulators. 4 bar for the Go EFI and Power Adder models and 3 bar for Mean Street and Go Street models.

The components are VW/Audi, so they are designed around an OEM spec, but again, they are offshore and likely sourced from lowest bidder.

[JLMounce]

Replaced the regulator this week and I had a bit of time to do some test driving.

The regulator that came out of the FiTech showed no signs of issues. There wasn't a single piece of debris on the screen and the diaphragm held vacuum. That said the new Bosch unit did improve fuel pressure by about 8 psi and I no longer see a drop in fuel pressure with additional throttle.

Sadly it had no effect on how the engine is performing. But I did feel confident enough in it at low rpm to put some miles on it and burn off some of the fuel in the tank. That will be my final fuel related item to tackle this weekend, a new pump.

However I'm once again leaning away from this being a fuel issue. It would be great if the new pump cured this issue, but I'm not longer hopeful on that end.

Spring diagnostic tools are about as much, or more than much of the traditional dual springs I'm seeing, so I may opt to replace those regardless. I think these heads get set up somewhere around 1.7"IH but I'll need to buy some stuff to measure this. I've never setup heads or done valve springs before so this is going to be a pretty big learning experience.

I'd certainly love some recommendations here. Tried getting some from comp, but spend about an hour and a half on hold before giving up on that. I also haven't been able to get ahold of KRE to see how the heads were originally set up. Hopefully I'll be able to get in touch with them next week.

I do have a small annoying leak from the thermostat housing that I need to take care of, so I guess now is as good a time as any to also remove the intake since I'll have to drain a bit of coolant anyhow. I'll inspect the cam and all of the lifters while I'm in there.

[HWYSTR455]

I have had 1 Blaster II and 3 Blaster SS coils go on me in a row, all around the 5-10k mile range.

My symptoms were that it ran fine for about 45 min, then it would slowly start dropping of performance from higher RPM to lower RPM, and then finally die.

It would start out as a high RPM miss, then it would continue, happening at 500 RPM less, then another 500 RPM, all the way down until it would die and not start. Each step it wouldn't go beyond the RPM the issue was at.

I even tried going to an HEI dizzy in troubleshooting that, coil in cap, and went through a few coils there.

Not sure if it was a MSD box issue or alt issue, but along the way of troubleshooting those were replaced, but after I went to a different E-core coil it all finally went away.

Now I run the Hyperspark coil, which is the potted type with a heat sink. Fingers crossed.

One tell-tale sign was as it would start missing/breaking up/RPM limited, the coils would be hot to the touch. And I mean like you could hold you hand on them at all. But I wouldn't use that as an indicator, a coil still could be bad in that case.

Valve spring. They should last to 100k miles or more. They may lose some psi, but doubt it would prevent RPM from going over 4000. Time too can add to the degrading life of springs, but each case is different, so you can say X years for all spring.

But just to say, a replace-coil test is an inexpensive test, and chances are you will be able to use the new coil as a spare or on another project.

Just like valve springs, plug wires go bad too. If they are over 5 years old, it's a good idea to replace them. Not saying that's the issue here, but if you're troubleshooting, you could scratch that off the process of elimination list.

Make sure you do the wire from coil to cap too.

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[steve25]

To rule out a ignition issue get the motor up to act up, then out of gear bring it up to about 5400 rpm for 2 to 3 seconds.
If the motor runs clean and does not break up I would say your problem is not ignition related or spring pressure related, but it’s load and fuel delivery related.

Having good fuel pressure does not guarantee that the needed fuel volume is there as the firing rate goes up.

[Formulajones]

Maybe I missed it but you had 40 psi before and a new regulator gave you 8 more psi???

That's only 48 and these systems are designed to operate with a steady 60 psi so unless there is something I missed that you posted it still sounds like a weak pump.

After you get the pressure where it belongs it would be a good idea to clear the learn table and start over because that is definitely corrupted. Over time it may recorrect itself on its own but there isnt much sense in driving the car around with a skewed fuel table waiting for that to happen.

[Jay S]

I can help you with picking valve springs, just need to know the IH of the springs. I don’t think you’re issue is with the valve springs though. It still sounds like your fuel pump won’t build pressure. It takes flow to build pressure, it doesn’t sound like it has enough flow at idle to build 60 psi. Probably gets worse as it tries to add fuel.

[steve25]

How can you help him pick springs if you do not know what retainers he has?

[johnta1]

Is fuel tank vented?

[Jay S]

Originally Posted by steve25

How can you help him pick springs if you do not know what retainers he has?

Yep, need know that too. The head were set up by KRE though, I can probably tell him which retainers it has just from the spring IH.

[JLMounce]

Originally Posted by HWYSTR455

I have had 1 Blaster II and 3 Blaster SS coils go on me in a row, all around the 5-10k mile range.

My symptoms were that it ran fine for about 45 min, then it would slowly start dropping of performance from higher RPM to lower RPM, and then finally die.

It would start out as a high RPM miss, then it would continue, happening at 500 RPM less, then another 500 RPM, all the way down until it would die and not start. Each step it wouldn't go beyond the RPM the issue was at.

I even tried going to an HEI dizzy in troubleshooting that, coil in cap, and went through a few coils there.

Not sure if it was a MSD box issue or alt issue, but along the way of troubleshooting those were replaced, but after I went to a different E-core coil it all finally went away.

Now I run the Hyperspark coil, which is the potted type with a heat sink. Fingers crossed.

One tell-tale sign was as it would start missing/breaking up/RPM limited, the coils would be hot to the touch. And I mean like you could hold you hand on them at all. But I wouldn't use that as an indicator, a coil still could be bad in that case.

Valve spring. They should last to 100k miles or more. They may lose some psi, but doubt it would prevent RPM from going over 4000. Time too can add to the degrading life of springs, but each case is different, so you can say X years for all spring.

But just to say, a replace-coil test is an inexpensive test, and chances are you will be able to use the new coil as a spare or on another project.

Just like valve springs, plug wires go bad too. If they are over 5 years old, it's a good idea to replace them. Not saying that's the issue here, but if you're troubleshooting, you could scratch that off the process of elimination list.

Make sure you do the wire from coil to cap too.

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This is worth a shot here. The car has a Blaster II in it currently and I do have another known good Blaster II. I keep it on hand because these are a somewhat known item. I can swap those easy enough. I do also have a known good HEI that I can stab in to check. I'll have to unloom and repin some wires to do that however.

I haven't checked the plug wires. They went on with the FiTech, so they are 10 years old as well. Nothing overly fancy, just a set of Moroso Blue's. Probably worth replacing to check that off the list, however the car doesn't act like it's missing spark.

Originally Posted by steve25

To rule out a ignition issue get the motor up to act up, then out of gear bring it up to about 5400 rpm for 2 to 3 seconds.
If the motor runs clean and does not break up I would say your problem is not ignition related or spring pressure related, but it’s load and fuel delivery related.

Having good fuel pressure does not guarantee that the needed fuel volume is there as the firing rate goes up.

Part of the ignition control syncing is to check spark at the engine and at the computer at various points in the RPM range. I did recheck this last weekend, including above 4000 rpm. Usually have to keep the revs there for 5-6 seconds while you verify timing with the light. With the system locked at 30 degrees, I have stable readings from 1500 through about 4500 where I checked it. Might be worth holding it around 5000 or so to test.

Originally Posted by Formulajones

Maybe I missed it but you had 40 psi before and a new regulator gave you 8 more psi???

That's only 48 and these systems are designed to operate with a steady 60 psi so unless there is something I missed that you posted it still sounds like a weak pump.

After you get the pressure where it belongs it would be a good idea to clear the learn table and start over because that is definitely corrupted. Over time it may recorrect itself on its own but there isnt much sense in driving the car around with a skewed fuel table waiting for that to happen.

I should better clarify that. Prior to the FPR replacement it would run around 50 psi at idle and drop to 40 psi when you rev the engine. With the new FPR in place it provides a steady 58 psi at idle and does not drop with engine RPM. What I can't see is what it's actually doing under load vs a free rev. I only have a mechanical gauge on the inlet.

I have time to install the new pump this weekend, but weather will keep me from testing that until this week.

Originally Posted by johnta1

Is fuel tank vented?

Yes, the tank actually has two vents. One from the main tank itself and another from the pump hat. These use 1/2" fuel hose that Y together and vent in the factory 69 Firebird location.

[JLMounce]

Originally Posted by Jay S

I can help you with picking valve springs, just need to know the IH of the springs. I don’t think you’re issue is with the valve springs though. It still sounds like your fuel pump won’t build pressure. It takes flow to build pressure, it doesn’t sound like it has enough flow at idle to build 60 psi. Probably gets worse as it tries to add fuel.

Originally Posted by Jay S

Yep, need know that too. The head were set up by KRE though, I can probably tell him which retainers it has just from the spring IH.

If the new fuel pump doesn't cure the issue, I'm going to purchase an IH micrometer and some checking springs. I can get that information from there.

[steve25]

The pump you have now could have developed a poor power connection and can’t pull the amperage it needs to maintain its speed under load.

[JLMounce]

Originally Posted by steve25

The pump you have now could have developed a poor power connection and can’t pull the amperage it needs to maintain its speed under load.

Certainly possible. I purchased a complete rebuild with the new pump including a new pigtail, just in case that was an issue.

[johnta1]

Yes, the tank actually has two vents. One from the main tank itself and another from the pump hat. These use 1/2" fuel hose that Y together and vent in the factory 69 Firebird location.

Check that one or both aren't clogged. (had spiders build nests in them)

[JLMounce]

Originally Posted by johnta1

Check that one or both aren't clogged. (had spiders build nests in them)

Certainly worth checking.

[HWYSTR455]

There are a number of gauges now that use transducers, could add a port, and run a gauge during testing, even in the future. When you don't just remove and cap the port.

Unfortunately, the transducers are not inexpensive, but very accurate. Instant readings, and it's possible to even log, if you have a logger. (Without a gauge)

If you don't have a logger, there are some 3rd party inexpensive ones, like the Innovate one:

https://www.summitracing.com/parts/inn-39140

Not sure if the FItech ecu has logging built in, never owned one, maybe someone else can chime in on that.

Logging is great for troubleshooting, and for tracking mods/tunes.


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[Formulajones]

I'm not familiar with Fitech, does it have extra inputs and outputs like Holley does?

My Sniper has extra inputs and outputs, so I run a transducer on the fuel line, go into the computer and tell it fuel pressure and check the necessary boxes etc.... so I can now read fuel pressure on the touch screen. Did the same with oil pressure.

The nice thing about that is that Holley now automatically will datalog those features once they are added so I don't have to try and stare at gauges on WOT runs, just datalog and go back and look at it. I've also set safety features along with the added data so if something is out of range it will alert me.

Might be something to look into in the future. Maybe someone more familiar with Fitech will chime in and explain if any of that is a possibility.