Fitech problems

[flyinlow]

I went to the Chrysler power Classic this weekend. Tried out the EFI. The engine pulled strong thru first and second but seamed to have a power drop off about 100mph. After a couple 13.10/ 103mph runs I was sitting in the staging lanes for about 20 minutes . When I went to start for the third run the engine would not start. Cranked and cranked. Finally recycled the ignition switch twice and it finally started. I let it idle for 1o minutes waiting to run. Went 12.84/104 , still seaming to not pull as well in third. The car can go faster than this.
Went home after this. I didn't want to get stuck in the staging lanes. When I got home the car restarted several times with no problems.  

I will call Fitech on  Monday. Any ideas ?      

[myk]

You've gone faster with your carb setup? 

[flyinlow]

You've gone faster with your carb setup? 

Yes.  12.64/107   different day I admit , slightly cooler

The car felt like it was pulling harder than before , then seamed like I let up on the throttle. I did see the A/F ratio  got leaner. I thought I saw 13.8 A/F  toward the end. of the run. Will start with doing some fuel tests on the stock fuel system part. Maybe fuel pump or push rod worn. 

Bigger concern is the not starting hot in the staging lanes. Acted like it was vapor locked which I did not have problems with before. 

[myk]

Ok, I thought you had to run an electric fuel pump with the Fitech?

[flyinlow]

Yes, you do. The engine driven Carter fuel pump feeds the Fitech fuel center attached to the radiator support. It has a float similar to a carb to keep it at the proper fuel level. Inside the fuel center a 58 psi electric pump sits in a"can" with about a quart of fuel in it. The high pressure electric pump feeds the throttle body. The ECU in the throttle body energizes the electric pump.



http://fitechefi.com/default.asp.pg-GoEFISystemFuelCommandCenter

[68CoronetRT]

You could also be experiencing vapor lock inside the command center, there's a huge thread about it on a Chevelle forum, in the end the guy ended up going with the Tanks Inc. setup and intank fuel pump, problem solved.

I bet your running out of fuel by the end of your pass. May need a larger mechanical pump. You should be able to data log the pass and go back and view the fuel pressures, I bet it drops off which is why its going lean.

[flyinlow]

You could also be experiencing vapor lock inside the command center, there's a huge thread about it on a Chevelle forum, in the end the guy ended up going with the Tanks Inc. setup and intank fuel pump, problem solved.

I bet your running out of fuel by the end of your pass. May need a larger mechanical pump. You should be able to data log the pass and go back and view the fuel pressures, I bet it drops off which is why its going lean.

Yea, I am thinking along those lines too.  Want to install a gauge in the low pressure side that I can read while driving and figure out how too do the data logging.

Some cars have ready to install tanks with pumps in a well available. Not my 73 Charger unfortunately. FiTech claims their Fuel Command Center is the best way to feed their throttlebody's.   It is suppose to support 800HP. The Fuel center in in front of the radiator support and behind the passenger side headlight bracket. One of the fresh air tubes draws  air right past it on its way to the air cleaner. It does not seam to get very warm.

[c00nhunterjoe]

Put a fuel pressure gauge between your stock pump and the fi unit 1st. See if its dropping, then check fi pump pressure

[John_Kunkel]

The FI Tech Command Center has a built-in low pressure gauge to show the incoming fuel pressure in addition to the output pressure.

[Troy]

The FiTech unit has a non-adjustable regulator (58 PSI) and all unused fuel will go back to the Command Center. However, if the CC is running out of fuel...

It does sound like vapor lock in the staging lanes (to me any way). I wouldn't think that should be an issue with EFI. Is there a chance you have air in the lines? I know there's a specific process to prime the system but I don't know the symptoms if it's not right.

I just purchased a GoEFI system but went with the Tanks setup for fuel delivery. Partially because the CC is back ordered for a really long time, partially because they have had some "issues", but mostly because I will eventually move to port injection and I want all my cars to have similar configurations.

Troy

[General_01]

I have a question. Anyone think of any issues with running a return line from the throttle body and tee it in with the return line from the Command Center to the tank?

I experience the same issue as the OP, but I was just out driving. I go on a drive and after about 15 minutes the car sputters and dies. It doesn't want to start after that. If I sit for about 5 minutes it starts up and I drive on. Not sure how much farther it would go before it did it again because I usually stay within 5 minutes of the house and I just drove it back home after that happened on both occasions.

The system can run "returnless" with the CC(even though you do need a return line from the CC to the tank, so it isn't really a "returnless" setup). I am using the stock return line in my '71 Bee for the line back from the CC and am considering doing this.

[68CoronetRT]

On the Chevelle forum it ended up being the tank vent line was not venting(below the tank and T-'d into existing vent from tank) and it was making the return line from the CC to the tank not really work and therefore causing weird delivery issues. He was able to test this by disconnecting the vent line at the CC and fuel started pouring out of it. If I remember correctly.

The vent system on the CC is a known issue to cause problems with fuel delivery. Look it up, people have been returning them with little help from Fitech. Once I read that thread I went the Tanks route and am starting the install today.

[General_01]

I read a lot of the thread on the Chevelle forum and it looks like what I propose is not an option because that was what they were running into with fuel in the vent line.

[flyinlow]

Talked to Fitech. They talked me thru slowing down the electric pump at idle and low power settings to help reduce heat build up in the command center. Give it a try.

Will try to do the data log tomorrow and plumb  a low pressure fuel gauge that I can read while driving.

I did do the prime initially.

Thanks for the reply's. For now my old carb and five feet of fuel line are in the trunk.

[69wannabe]

Talked to Fitech. They talked me thru slowing down the electric pump at idle and low power settings to help reduce heat build up in the command center. Give it a try.

Will try to do the data log tomorrow and plumb  a low pressure fuel gauge that I can read while driving.

I did do the prime initially.

Thanks for the reply's. For now my old carb and five feet of fuel line are in the trunk.

Hang on to that carb and fuel line!!!! I swapped mine back to the old carb today, mine had weird spell this weekend that had me scratching my head. Cutting out and sputtering off idle all the way home from town. It's like it was trying to vapor lock or something. At least I know how my carb is going to react to heat and cold and how to work with it. Going to run the carb for awhile and see if there are really that many advantages to the efi or not.

[myk]

Wow.  That sucks...

[flyinlow]

Talked to Fitech. They talked me thru slowing down the electric pump at idle and low power settings to help reduce heat build up in the command center. Give it a try.

Will try to do the data log tomorrow and plumb  a low pressure fuel gauge that I can read while driving.

I did do the prime initially.

Thanks for the reply's. For now my old carb and five feet of fuel line are in the trunk.

Hang on to that carb and fuel line!!!! I swapped mine back to the old carb today, mine had weird spell this weekend that had me scratching my head. Cutting out and sputtering off idle all the way home from town. It's like it was trying to vapor lock or something. At least I know how my carb is going to react to heat and cold and how to work with it. Going to run the carb for awhile and see if there are really that many advantages to the efi or not.

I did pull the pump and check the push rod against a new one, it was fine. The pump is a Carter street pump. I bought the fitting and a gauge to tap into the low pressure side with enough copper tubing to tie wrap the gauge to a wiper blade. Hope to install and drive this weekend.

I had the car to a cruise in Memorial Day 85* and got stuck in traffic. It ran fine, no hot start issues.

I always ran an insulator under the carb, but I did not put anything under the FiTech but the supplied gasket. I might try one if the hot start issue rears its head again.

[68CoronetRT]

Seems like any Fitech related problems always have the FCC in the mix. I've never heard of the Tanks setup with in tank pump having any fuel related problems. So far mine is running 1000x better than ever before. Just my 

[myk]

I thought an in tank setup/electric fuel pump was mandatory on these things...

[MSRacing89]

They claim it will support that kind of HP, but it's simply not true.  Not with a BB type motor.  We run EZ-EFI and ran into the same situation.  Bottom end feels good, along with many other aspects tuning, but we lost some speed on the top end.  It was falling on its face at around 120mph on long straightaways.  We are making close to 600hp.  So switched to Multi-port and went to this throttle body.  http://www.fuelairspark.com/fas/4-barrel-throttle-body-high-flow-4150-flows-1375-cfm-includes-tps-iac-fastenershtml/ .  Now it pulls all day long, no lags, stumbles, etc.

If you are running mid 12's, these off the shelf set-ups are simply not enough flow.   

[John_Kunkel]

Talked to Fitech. They talked me thru slowing down the electric pump at idle and low power settings to help reduce heat build up in the command center. Give it a try.

Care to share the procedure?

[flyinlow]

Talked to Fitech. They talked me thru slowing down the electric pump at idle and low power settings to help reduce heat build up in the command center. Give it a try.

Care to share the procedure?

Bryce recommended this change to help reduce the heat in the FCC at lower power setting.

At the main menu select #6 Go EFI Pro Tuning

At the tuning menu select #11  Fuel Pump Control

At the Fuel Pump Control menu select # 7 PWM low .....original setting 87...Bryce recommended reducing to about 40 which I did and of course send to ECU after the change.

I assume PWM is pulse width modulation , so reducing that number would reduce the percentage of time the pump is receiving current.  So less heat build up in the FCC . 

[flyinlow]

Starting to wonder If what 68 Coronet RT ,Troy and other's have mentioned about FCC. I thought is was a simpler way to make the swap and FITech recommends it as the best way.

The pump in the tank with a return line would keep the fuel cooler and I suspect I may have to go that route. For now I will do some more trouble shooting.

[Troy]

I looked at alternatives because
A. I plan to switch to sequential port injection at some point
B. The FCC is back ordered forever

I don't know how many have been sold but I'm reasonably certain that not everyone has a problem with them. It's probably heavily dependent on power output and driving style. From what I hear, the large majority of people purchasing these systems are for carb replacement on mild builds (ie cruisers under 400 hp - very likely under 300 hp). I see many, many posts on small block Ford and Chevy forums. It's probably very happy in that capacity.

Troy

[68CoronetRT]

You are right about the fuel cooling down on its way back to the tank where it joins your fuel supply that is already cooled. The design of the FCC isnt very great in the sense of how surge tanks normally work on a vehicle. Normally the unused fuel goes back to the main fuel tank, with the FCC it just circulates inside the tank heating everything up and probably boiling as it hits the manifold which is causing the stumbling.

The chevelle form is a good read if you have the time. The guy went through all the issues with the FCC and then went with the Tanks setup and since has had zero issues.

Also think about car manufacturers today. How do they run their fuel systems?