Intermittently keeps restarting fuel and prime on initial "key on"
Been having a weird problem with my 30004 lately. Sometimes, not always, when I turn the key on (12V to white wire etc) the unit will start priming the fuel pump (like usual) and does the prime shot but then sounds like it restarts this process by itself randomly over and over continually which can last for like 10 or 20 or 30 sec at times.
While it is doing this the voltage indicator on the handheld plummets very low to like 4V and dances around until it eventually recovers to 12+ volts and then it stops like normal waiting for crank etc. I know the battery and connections are all good I have checked them all over and over. The battery volts is not dropping as I have a fluke meter on and always read above 12 etc. I have even tried running another 12V battery to just run the fitech and still get this random but fairly regular issue. No fault codes are generated either.
Never seen this before. My theory at this point is the fuel pump amp draw is maybe causing the ECU to see a voltage drop possibly ?
Does anyone know where the volt reading on the handheld is referencing ? I am assuming it is the voltage at the incoming red wire and not the white wire ? I know these Fitech are very sensitive to voltage issues to run right.
When this issue happens it of course has issues with starting and running but when it does start and run it works nicely. Annoying, seems like one glitch after another with these things.
Just seen a topic/post by DerekO which had the same issue as I'm seeing.
"Key On cycling and hard starting"
Unfortunately looks like it may be an ECU replacement issue 🙁
So I did some playing around and using ECU programmer reloaded the hex file (which I have done before) and my latest program. This seemed to help for a while but then this same "cycling" problem returned.
Dismantled the Fitech and removed the ECU to see if any wires were pinched or grounds loose etc. Everything looked OK up to the point where it goes into the potted ECU. The wires are all mashed in there kind of tight so you must be careful pushing it back together. It seemed better but problem still re-occuring at times.
Next I put a relay on the fuel pump with a fused supply right from battery controlled by the Fitech orange wire, thinking this will help the ECU out since it is only powering a relay through the main batt red wire and not the pump directly.
I should note my pump is pretty much stock and only draws maybe 7A at most so it should handle it regardless. My battery volts for sure stayed around 12-12.5V all the time. This problem occurs at key on and not because of cranking etc.
Tried it several times and it seemed better yet it still did the "cycling" issue once. So I'm thinking the ECU is just intermittently glitching somehow and I am just chasing the issue around. Also when it glitches like this and eventually settles it will sometimes start and then run rough like the ECU is not really happy etc. I don't trust that it won't quit completely now.
So I have decided to order a replacement ECU 30004-1 and give the Fitech one more chance since I do like the TBI setup and don't want to really change it. Perhaps I just got a bad unit. It happens, I get it, but if the replacement ECU has more glitches then in my opinion it is not a good product and I'll move on and take the hit.
Well I got my new replacement ECU and installed it. Wasn't a terribly hard thing to do.
So far so good. Fired right up and have not experienced any of the problems I had before with cycling or O2 sensor faults or low volts etc.
Perhaps I just got a bad one.
However, I do think that running the fuel pump off a relay regardless (rather than through the Fitech) does help reduce the draw on the main red batt lead and may help with any voltage drop issues to the ECU. Problem with doing that is you lose the PWM feature if that is important to you etc.
I also rigged up an off-delay relay to the main power wire to disconnect the Fitech after 30 sec. This allows the Fitech enough time to save the settings on key off and prevents it from drawing down the battery if it sits for an extended period of time etc. So far no issues with the Fitech losing any settings.
You mentioned my post on similar experience. The ECU was my problem and Summit swapped the whole unit to expedite. This spring when the car was removed from storage, it had intermittent hot no starts. It was loosing timing control after a heat soak. Let it cool down and it would fire up and run flawlessly until the next heat soak. Same thing, customer had swapped out at summit and it ran flawlessly for a couple months after i installed. This time i did install a 1/2" plastic carb spacer to prevent manifold heat transfer in hopes this would help. Now the fuel pump driver has failed in that unit. I had fuel pump run from relay since day 1 so load shouldnt have been an issue. This customer has had 3 ecu failures on this car in less than two years. I will never install another Fitech. I have used Holley, Accel DFI, and Fast EFI before and never had issues like this. Power wire is coming directly from battery. New grounds chassis to engine, battery to chassis. When the unit works, it works well but these failures are getting rediculous.
I hear ya its very frustrating, especially if your installing for a customer !! I'm giving my Fitech one more chance.
So far the new ECU has been behaving nicely. Haven't had any repeat problems I was seeing before. I have started it up numerous times but have yet to get it on the road this year and do some real tuning etc.
If it starts giving me grief I'm cutting my losses and will look at a new setup.
Update: I am happy to report that the new ECU seems to have fixed all the faults and issues I was having. No more cycling issues at key on and no more O2 trim faults/issues after a couple months. It is running quite well and starts reliably every time...so far so good.
I am still running a separate fuel pump relay (triggered off the orange wire) and also a delay off relay on the main power to disconnect the Fitech from battery completely between starts.
New update I felt I should post rather than just go silent.
I am sorry to say that I just could not seem to escape the faults that plagued my Fitech system, even with a new replacement ECU. The same O2 faults returned shortly after so s I mentioned previously enough was enough.
As a car guy I expect a few hiccups to be encountered on these aftermarket systems and feel that I gave the Fitech more than enough patience and the benefit of the doubt in this regard. In the end I went to another system and it has been far superior in almost every way for the past 2 years now.
This may not be what current Fitech users want to hear but that is my real life experience.
I assumed you went with the holly system? You may have had a bad O2 Sensor with the fitech . Also with the new ECU, did it come with a external fuse/relay box? Those are much better version of the ECU.
No I went with the pro flo 4 and love it. A few little things with it as well but completely resolved and reliable.
It wasn't just a bad O2 sensor. I tried almost everything under the sun including a new one. It would freeze up every so often. I contacted tech support and eventually they wanted me to send unit in. It was off warranty by then so I decided to just order a new ECU at the time rather than have them just replace it and had to pay anyway as per thread above etc.
I did lots of homework and tried all kinds of different scenarios to solve the issue. I don't consider myself a rookie when it comes to these kind of things where it was my own lack of knowledge or a faulty install causing all the problems etc.
As described also had this weird intermittent restart problem (as above) which also returned (all with the new ECU). Not sure about this new style ? Both my ECU's had external fuses.
Anyways doesn't really matter anymore I have moved on and actually sold my Fitech to someone for parts with full disclosure etc. I like the idea of the Fitech but there were just too many problems and I couldn't trust it anymore.