FiTech EFI 400 idles up and down
ALL,
I have a 1973 Mustang with a re-built 1985 GT roller with Tri-State aluminum cylinder heads, Mallory Un-lite distributor, air gap aluminum intake with FiTech EFi 400. I have a Howard Cam. I am trying to locate cam card.
From day one, I have had the engine/EFI 400 running with the engine would idle, then I can hear the FiTech injection system thus running up the RPM’s. Then, it would drop back down, then in a few seconds, it would repeat.
Discovered intake manifold was not re-torqued after initial break in period. Removed, cleaned up, re-installed Air-Gap Intake. Brought engine to operating temperature. Re-torqued intake bolts.
I still have the same issue. The engine runs at its low RPM’s, then it runs the RPM’s, then back down.
I have checked all the wiring, vacuum ports, timing, reset the FiTech to factory. Same thing. Also, it runs rich also.
Any Suggestions would help.
Thanks
mustang7173
Let's start with exhaust. How and where did you place the O2? Do you have your exhaust all hooke up or open?
I sent this picture of my 02 location and FiTech support it was OK. I also sent my entire system back to FiTech for evaluation. The stated it worked fine. They want me to check my wiring. Also, they are sending me a replacement C02 sensor.
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When you say it runs rich, are you saying the handheld or logs are showing rich, or that the exhaust seems like it is rich?
It might be worth having the sensor bung welded in, that will make sure there are not any air leaks around the sensor.
Tr8driver,
No. Logs are clear. I am thinking it may be EMI, RF, or even a grounding problem. I sent the Fitech EFI 400 back to Fitech for testing and they did not find any issues. They did include a new O2 sensor.
I am basing the EMI from another Forum area where a user was having rich problems and covered his tach wire with mesh wire cover, ferrites, and grounded the assembly. He notice a difference on how his EFI ran.
All,
After I had vacuum smoked the engine, I thought my valve cover gaskets were the source of the leaking smoke. So, I replaced them. Well, smoked again after valve cover gasket installation, and lord behold, then ,dag nabit, the intake is still leaking in three places. Da Gummit!!! After all of the work to install and re-torque procedures have been followed. I suspect this has been an issue from the day of after rebuild installation.
I found this YouTube install that I am going to follow.
I will update post later on after I re-install my intake.
Thanks
mustang7173
Muatang7173,
I have always wanted a smoke machine. Which one do you have? Are you happy with it?
Hello Austin,
Yes. I helped me determine that my aluminum intake had a vacuum leak.
I believe the seller is military!!
Thanks
mustang7173
All,
Finally got my intake sealed up. It runs much better. I still have the running rich problem. I am reviewing forum threads to see if can help me resolve this issue.
mustang7173
All,
Per Austin Dehaas,
Ok, this gets us started. Step 1, get the cam specs. Very important for tuning.
Step2, install a fuel pressure gauge. Having the right equipment does not mean the pressure is correct. I tap one of the fuel rail caps and either screw in a gauge or use a proper hose for a remote mount in low profile applications.
Step 3, get a Delco temp sensor. Fitech sensor is junk. Can't remember part number, but use a temp sensor for a 97 Silverado with 350. GM used the same sensor for many years.
We need to double check your initial settings. Fitech tends to lose memory during first starts. Post a pic of settings.
With gauge installed, turn key on and verify prime fuel pressure. Should be near 52psi. If high or low, I will have more questions.
Once these steps are checked, double check your ignition timing and torque on intake/header/collector bolts. Can't have leaks...
Adjust idle to fully closed and then screw in 1/2 turn. Try to start. If no start, adjust another 1/4 turn. Once running, key an eye on gauges and wait for engine to warm to operating temps. Then and only then you can adjust IAC steps. Follow Fitech instructions for adjuatment.
Do you have full exhaust installed?
I am using the built in pressure regulator on the EFI 400. Maybe I need to add an inline pressure regulator. In step 3, he mentioned that the Fitech temp sensor is junk. Maybe I should get the Ford version?
I do not have the Cam specs. I went back to my builder and all of his paper work on the rebuild were thrown out. Crap.
What do you think?
mustang7173