Fedup with Fitech

[tonysrt]

Well I finally threw the towel in and went and took off the 2 throttle bodies and returned to the sanctity of 2 Eddy 1406 carbs. The straw that broke this camel's back was no start when hot. I went to gas station and filled my tank and went to start and cranked fine just no run. After a half hour called to have car flat bedded home. Next day car started fine, ran it for a while, back in the garage shut it down and tried to restart again and no go. The engine is a gen 2 Hemi and I have had this on the car for two years and this is the 1st time with the no start problem. Put the Eddy's back on and in this 95* weather we're having car started right up after a 10 minute wait.
I tried resetting the Fitech calibration to stock but no help. The idle was erratic at times and the return spring in the throttle was a bear to operate. The other thing was I didn't want to spend half a day on the phone with a tech rep. Fitech should give a little more info than a folder how to install it, maybe some trouble shooting hints.

 

[moparlee]

Well that's too bad. Seems like it should have been the other way around. Do you know if others have had that same problem?

 

[tonysrt]

I read a thread where somebody had vapor lock with Fitech and was told a carb spacer might help. I didn't have them on, but in 2 years prior I didn't have this problem. Maybe this F.I. isn't the complete answer yet. I know my 10 SRT with F.I. runs great. But with the other problems I had with it, I just felt it was time to give up.

 

[AUSTA]

Have you anyone check the pulse from the distributor when hot .
I think there is a screen where to can see the RPM whilst cranking the engine if the Fitech doesnt see a pulse it wont add any fuel only a squirt of start fuel
When you turn the ignition to start after around a second you will see a squirt of fuel for the initial start then once it senses RPM & throttle position it will start to add more.
When you crank when hot does it attempt to start then immediately stop or it does fire at all.
Try turning your key off & on a few times so it will add more start fuel each time the Fitech senses ignition on.

 

[tonysrt]

I did all of the above even jumped fuel pump and it would fire and die. I turned key on and off till I heard the click and tried to start and no help. I was getting a very good spark in the run position from my MSD Dist. and 6al box.

 

[AUSTA]

So when you hear the click have you physically looking down the venturi are all four barrels getting a squirt of start fuel.
I take it you get your pulse from the grey tach wire on the MSD

 

[tonysrt]

The car starts fine cold. If after hearing the click and car doesn't start there is something wrong with the throttle body. I never looked in to see if gas was coming in. Hitting the gas pedal was no help. So if no gas was going in, how could I even begin to fix it? With jumping fuel pump still wouldn't continue to run. I thought F.I. eliminated hot start and cold start problems. Don't forget after 2 years I'm having this problem.

 

[AUSTA]

It wont add fuel from the gas pedal until it senses the engine has started.
The click as you know is the sound of the injector pulse have you put a pressure gauge up at the carby as it sounds like the pump is not supplying enough pressure when hot.
It only has the inbuilt fuel pressure regulator inside the unit if you get over 40 PSI at the body you would say fuel is present the other way would be to see if you are getting return fuel from the body which would mean the regulator is doing its job & your filters are clean
I am trying to go through the elimination process the click when it is hot sounds like the injectors are opening but there is not enough fuel pressure.
I run a few fitechs & have had a couple of small problems but are generally very reliable.
I had a blocked injector & when i looked down the body only 3 venturis would squirt.
What pump are you running is it getting full voltage when hot

 

[tonysrt]

I run the pump off the F.I. pump wire, but when I jumped it I went straight off the battery for power to make sure it was getting full voltage. I'm running the walbro pump rated for 600 HP. I have a gauge on and it was almost 60psi with pump running. So if injector is clogged, why wouldn't it show up at cold start and how do you correct it.

 

[AUSTA]

I was explaining what happened with mine for yours not to work you would have to have all 4 injectors blocked.
It sounds like you have been thorough with your diagnosis if you have full pressure at the body the only is to check that is is actually giving that squirt when hot.
If the internal regulator was jammed fully open you would not have the 60psi pressure as the fuel would bypass
if it was jammed closed when hot you would have high pressure but no return fuel

 

[tonysrt]

Austa thank you for you're input to my problem. Maybe when weather gets cooler I'll give it another try. Right now I'm enjoying the dependability of the carbs.

 

[6PKRTSE]

Sucks to read about your Fi Tech problem. I was thinking about their 2 barrel throttle bodies & adding an injected six pack on my Charger but now I am having second thoughts.

I had the exact opposite problem with one of my Gen II Hemi's. I was having vapor lock issues with dual Carters 750's (basically Edelbrocks). I put two phenolc spacers under the carbs & the hot start issue went away.

 

[tonysrt]

The big problem I see with this F.I. is that I couldn't trouble shoot the problem. If something electronic broke down and quit, I don't know how or where to begin. At least with the carbs you can look inside to see if their working. I really felt lost when I encountered the hot no start. Considering I put the Hemi in and a 5 speed tremec, I feel I'm a competent mechanic not to mention the rally gauges I installed from a 72 Challenger and all the other little things that go wrong that I have to correct. But this made hit a dead end.

 

[Dutch 165]

Can I ask what fuel tank and vent you are using, planning on installing efi on my 71 Barracuda. When I read what fuel pump you were using I'm thinking it must be a Tanks fuel tank. I'm trying to figure out the vent part of the conversion since the factory had a plumbing array that I don't think will transfer over.

 

[tonysrt]

I have a tanks Inc. tank with a rollover vent in the trunk. There are three outlets on the pump installation kit, a feed, return and the vent.

 

[Dutch 165]

Thanks for the reply, I'll get going on that project. May try a sniper setup, was going the Fitech route but have heard some good and not so good about their tech support. Did you use a 3/8 supply line?

 

[tonysrt]

Yes, feed and return are 3/8.

 

[440 guy]

I have had the exact same problem with the fitech on my 440 ever since I installed it 3 or 4 years ago. Figured it was a fuel delivery heat/vapor problem but insulating the fuel lines etc didnt solve anything. It just happened to me again yesterday and by chance I had the hand held controller hooked up this time, normally I dont. There is no rpm showing up on the hand held, just reads 0. After messing wit it as much as I could for about and hour I called a tow truck. Of course by the time we got it towed home and unloaded a couple hours had passes and it fires right up. But what I have found through all my testing and checking is I have an RPM signal all the way up to where the wire.goes into the fitech unit, so I'm guessing there's a bad solder joint connection on the blue wire where it connects inside of the fitech. I think the heat transferring through the engine into the throttle body is enough that that bad connection separates when it's hot But reconnects just enough after it cools back off to get the signal and make it run. I will be contacting fitech after the holiday

 

[tonysrt]

I disagree with you about a bad connection because so far I've heard of three people with the same problem. I believe it is circuitry gone bad when hot because it starts good when cold. If there is any way to troubleshoot the problem I have no idea. There was mention of the cooling sensor wasn't the best, I did change mine but never had the F.I. back on. It's hard to beat Carbs because no electronics to go bad.

 

[gzig5]

It very well could be an internal connection issue. We deal with this kind of issue at work all the time. As electronic parts get smaller and smaller you have less leeway in misalignment from thermal expansion. Sometimes a good shock can reset an interface. Try giving the unit a good whack with the plastic handle of a screw driver and see if the behavior changes. Or hit it with some freeze spray or carb cleaner on the throttle body.