Vacuum line at FPR

[Paddywhack]

Thanks Andy, The beer will flow my friend! Schrade, you have given me for more than 2 cents worth of knowledge and I appreciate every penny of it! I'll be back out in the garage tonight going over the fuel lines again

 

[Schrade]

Liquid refreshment is fine after (and during) the tune. But while blowing through the pump to check the check ball, make SURE to use a spark arrestor on your aerosol refreshments UH HUH!

 

[Paddywhack]

good point! Last thing I need now is an unwanted spark in a confined space! Spoke with the folks at FIC, nice people there also....seeing that I dont know which injectors are in there and the condition, I went ahead and ordered the Bosch III design in the 22lb range. This is plenty for my engine according to FIC, unless I spend alot of time over 7000 rpm, then I would realize a fuel starvation issue. (6000 rpm's if the injectors are 19lb for a 305). I dont plan on that, although once might be exciting! Back to more testing tomorrow on the pump and FPR. (something called work got in the way today). Amazing, never once thought about the small stuff like the fuel filter during the rebuild until you guys told me step back and look at the whole picture. New filter to be installed tomorrow also.

 

[Paddywhack]

Hi all....the vacuum line diagram shown in posts 3 and 4 of this thread...are we sure that is for an 1986 w/cast iron heads? coming out of the cannister I have a slightly different configuration. The larger line shown going from the cannister goes to an aluminum tube that runs between the driver side valve cover and the manifold. This tube then Y's out and one line goes into the valve cover and the end of it into the intake manifold. I will attempt a sketch and try to post it the way the lines run from the cannister on my car.

 

[Schrade]

Hi all....the vacuum line diagram shown in posts 3 and 4 of this thread...are we sure that is for an 1986 w/cast iron heads? coming out of the cannister I have a slightly different configuration. The larger line shown going from the cannister goes to an aluminum tube that runs between the driver side valve cover and the manifold. This tube then Y's out and one line goes into the valve cover and the end of it into the intake manifold. I will attempt a sketch and try to post it the way the lines run from the cannister on my car.

According to the diagram, the vacuum tube between the dr side V/C, that goes to the intake, is a dedicated vacuum line, for the crankcase ventilation. That is a constant vacuum, pulling air from inside the valve cover, from the crankcase, from the pass side V/C.

ttx6 knows his stuff. You'll need to ask him to confirm vacuum routing for '86.

I'm seeing one interesting thing tho'; that diagram shows IN ADDITION to the EVAP purge getting routed through the EGR port (which I KNOW is how L98 works), a DEDICATED EVAP purge solenoid, that contradicts EVAP vac leak causing false DTC 32 EGR :confused

 

[geekinavette]

The custom chip you have (from Harris or whatever) will be programmed based on injector flow rate, displacement...etc. Verify with them what injector flow rate your chip is set up for. If the flow rate of the injector doesn't match the chip...it'll run like crap. (makes me wonder how they were able to provide a chip if the injector flow rate wasn't known?)

 

[toptechx6]

Hi all....the vacuum line diagram shown in posts 3 and 4 of this thread...are we sure that is for an 1986 w/cast iron heads? coming out of the cannister I have a slightly different configuration. The larger line shown going from the cannister goes to an aluminum tube that runs between the driver side valve cover and the manifold. This tube then Y's out and one line goes into the valve cover and the end of it into the intake manifold. I will attempt a sketch and try to post it the way the lines run from the cannister on my car.

I am not sure the diagram posted was for an 86, my purpose was to show that the vacuum supply to the FPR comes directly from the intake manifold. To the best of my knowledge that is true of all systems regardless of year or model.
After some research I am more confident that this diagram is correct for your 86 and looks more like what you describe in your post, hope it helps.

 

[boomdriver]

yes,
Fuel reg shares a line with the air control solenoid by the compressor. The other manifold fitting is dedicated to hvac only, and has a ck valve a few inches downstream where it also is a T near the distributor

Tha charcoal can in the nose has a T under it that goes nowhere. Its just a T to vent. That one throws most people off.

 

[Paddywhack]

At the time I had the chip burned, I did not know that an engine swapped had been made previously. I did know what I was going to install and remove for tha matter, and told Harris that I believed they were the stock injectors for a '86 L98. So, whatever injectors maybe in there, I figured by ordering the 22lb bosch III design at least now I'm back to being equal to what the chip was made for. Does that make sense?

 

[Paddywhack]

Yes Toptech, this newest diagram is exactly what is in my car. Now my EGR is gone and plated off, the egr solenoid is out and the vaccum at the TB is blocked. The AIR switching valne and AIR control valve are also removed, so I'll run a line from the FPR to the manifold and the HVAC line is in place. Plugged the FPR this morning, ran the fuel pump with the gauge on it still dropped immediately after the pump stopped, but now I smell gas when I took the vacuum plug off of the FPR. Might as well rebuild it while waiting for the new injectors to get here. Couldnt blow anything back through the pump.

 

[geekinavette]

At the time I had the chip burned, I did not know that an engine swapped had been made previously. I did know what I was going to install and remove for tha matter, and told Harris that I believed they were the stock injectors for a '86 L98. So, whatever injectors maybe in there, I figured by ordering the 22lb bosch III design at least now I'm back to being equal to what the chip was made for. Does that make sense?

As long as that flow rate is what the chip was programmed for...

 

[vetteoz]

The larger line shown going from the cannister goes to an aluminum tube that runs between the driver side valve cover and the manifold. This tube then Y's out and one line goes into the valve cover and the end of it into the intake manifold.

Sounds like the cast iron head L98's had the same setup as the CFI engines.
Canister purge line Tee's into the PCV line between PCV valve and intake port as you note; not direct to the TB as on later TPI engines. Either way purges gases still end up in the intake to get burnt

 

[Paddywhack]

Was able to get my hands on a hand vacuum pump. Put it on the FPR and it held 10mmHg indefinately. So much for the FPR..waiting for the injectors to get here, so I'm back looking at the pump again just to make sure.

 

[Schrade]

The custom chip you have (from Harris or whatever) will be programmed based on injector flow rate, displacement...etc. Verify with them what injector flow rate your chip is set up for. If the flow rate of the injector doesn't match the chip...it'll run like crap. (makes me wonder how they were able to provide a chip if the injector flow rate wasn't known?)

Good call uh huh - I just noticed the time frame for the chip burn.

:confused :confused :confused

What baseline figures were used for the burn??? I would call Harris NOW and get the printout/whatever paperwork there is, WITH baseline figures for the chip. I don't mean a receipt either - rather the printout for calculations.

Just out of curiosity, how much was this chip?

At a minimum, the calculation should show EVERY TPI 305 LB9 parameter, and how variation was calculated for EACH variation that you told them of - bore volume, cam specs, and whatever else you did (I THINK no variation is added for headers).

You HAVE checked for external leaks between the tank and the FPR? That's the next diags step after inspection of FPR vac hose...


edit:
Ok; I just went to the Harris Chips website http://www.tbichips.com/ Throttle Body Chips.

Throttle body injectors unload TONS of fuel (because there's usually only 2), whereas Port Fuel Injection (1 per cylinder/TPI/LT1/etc), drops LESS fuel in each injector.

And I noticed he says he uses datalogging/scanning to burn chips. This is how it's SUPPOSED to be done, IF AND ONLY IF it's already tuned, unless as I said before, some baseline is used with variables changed for each mod...

I suggest you get the paperwork for the burn...

 

[Paddywhack]

Will do that. As mentioned, last fall I knew I was going to rebuild at least the upper half of the engine, which I was told was the stock L98. I knew what cam I had purchased, knew about the the long tube headers and the elimination of the AIR and EGR. Once all the parts were here for the rebuild, I started stripping down the engine and first thing that struck me was the intake and exhaust valve sizes. Were not the same size as I had ordered, that lead me to look up the head numbers and then it dawned on me to measure the bore. Thats when I found out about the 305. The chip had been ordered for what I thought was a L98, with stock injectors, gave them the cam specifications, also informed them regarding the headers with the elimination of the AIR and EGR, which transmission, and other information. I paid $150 for the stage II chip. The only variable after the injectors come in is the overbore on the new block. I will call today and talk to them.

 

[Paddywhack]

Gonna change the fuel filter today...will go over every inch of fuel line from the FPR to the tank

 

[boomdriver]

dont forget the screen sock on the fuel pump itself !

That little wad of nylon has caused many a car to be towed. Its the first defense from dirt and crud in the gas lines. If the filter is dirty, the screen will be worse,.
The truely alarming thing is that IF the inline filter is dirty, ALL that crud HAD to pass thru the fuel pump...to get to the filter. Pumps are cheap.

 

[Paddywhack]

Thanks Boom, new pump installed when the new engine was installed...no idea when the filter last changed. Still not positive that its not the pump bleeding down...new injectors are due here today, so, i'll be posting tonight

 

[Schrade]

Thanks Boom, new pump installed when the new engine was installed...no idea when the filter last changed. Still not positive that its not the pump bleeding down...new injectors are due here today, so, i'll be posting tonight

Find out:

Cap the line at the FPR.
Install new injectors on the fuel rails.
Don't install the rails. Put a glass jar under each injector.
Prime the rails - ignition 'ON', with gauge on schrader valve.

If pressure drops, with no gas in glass, follow the lines to check for leaks. If no leaks, that leaves one place for pressure to drop to...


Harris fax anything to ya'?

 

[Paddywhack]

Ok guys...here's the scoop! Took the pump out today, could blow through the supply line and it was comming out through the pump. Took it back and got another. Installed the new injectors, fuel filter (old one was facing wrong way!) and the pump. Fired up and much better, but not quite right, still had a skip and fuel stench from the drivers side exhaust. No. 1 plug was soaked with fuel. New plugs, new wires and ROARED to life!!!!! Drove around town for an hour or so...just beautiful, great power and acceleration sounds incredible. Thanks to everybody for all the help...could not have done it with out you guys! Like Schrade said, (any many others) step back, start from step one. Who would have thought that a new fuel pump could have gone bad sitting here along with a plug go bad in three months. Hopefully the weather cooperates tomorrow and I can give her a bath and get a couple of pics up here! Thanks again! ( I had not talked to Harris as of yet, got quite busy in the garage today when things started)