Fitech Efi Install On 78 Cj5

Sir,

ok so then there is something else going on that is not letting it connect to ecu. either no 12 v key on ignition . ecu not seeing key on.

Which fitech unit is this?

Thanks,
John

Response

OK, when the key is on......
I can "write cal to ECU" and get "succeeded" or if I change a setting like engine cid from 355 to 308 and press "send to ECU" It says "Send to ECU Succeeded"
If I start the car it fires right up, so I assume it has 12V.
It only fails when I try to save the tuning data. with "ECU Response Error"

BTW I just went down again and performed everything listed above. to insure accuracy
This is a FiTech 30003

When I installed this unit I had to call tech support because the handheld screen kept going blank, I had to run a power wire directly from the battery to solve the issue.


Jay

 

So I probably carried that on too long , my apologies.

After many more exchanges and one phone call, I got files to do a software upgrade on my handheld unit. End result is I can now save my tuning data.

Now I need to go driving again.

 

I guess I didn't put it in this thread, I drove to Tractor supply for cat litter, when I came out the Jeep wouldn't start, and the High Pressure pump was running very fast, kind of like no gas. I turned on the electric pump and let it pump cool gas into the reservoir tank to cool it down. After a minute or two it started up and I came home.

Then I moved the reservoir tank and high pressure pump from under the hood to the frame rail under the driver seat, at the same time I ran 3/8ths steel line for feed and return lines. But the SS covered nylon fuel injection hose I bought for flex connections will not seal. It does OK on the barb fittings on the throttle body, So I've ordered more fittings and will try again when they arrive.

The pump was so noisy under the hood, but now I can hardly hear it, even with the door off, I am right above it, but it is very quite. Maybe because it is at or below the fuel level in the tank.

 

Final Review. Fitech No Stars.
My Jeep has always been my most reliable vehicle, I can get in it at anytime turn the key and go, ... grocery store or cross country. I ordered it from the factory in Sept '77 and picked it up Dec 23rd. My only complaint has been gas mileage.
To that end I decided on EFI. The Fitech unit was fairly easy to install, I had to call their tech support to cure the white screen problem on their handheld display, but other than that, it ran pretty good. first tank gave me 15 mpg. A big improvement over the 500 cfm Edelbrock carb of 10 mpg. subsequent tanks only got 13 mpg. I think due to a leak in the exhaust system.

I do not have engine tuning skills, I watched a ton of youtube videos. I learned that Fitech sets the tuning numbers for automatic transmissions. So I changed a few numbers and got it so when I pull into my drive way, it didn't stall. De-acceleration became my nemesis.

Short drives around town were usually OK, then the trip to Tractor Supply, as noted above. Then we had to go to California to help her parents. We loaded up the car hauler and left. After a slew of problems, the Jeep had to come off the trailer just after Albuquerque . It was up and down the mountain coming out of flagstaff that the issue began When driven over an hour and you de-accelerate for more that 5 to 10 seconds or less when hot, the air fuel numbers start to fluctuate and the engine will stall. Under normal conditions the fuel/air numbers are 13.8 to 14.2, when this occur rs the number jump to 20+. If you stop pop the hood and sit for 10 min it will restart and everything is normal. However once this starts and the engine is hot it usually occurs again within 15 min. I had hoped their "self Tuning Software" would eventually solve this problem, but it never did.

It seems being hot outside and the possible exhaust leak bring on this condition. If I had access to a computer and internet I might have tried to post up the data files to see if anyone here could see what was causing the issue. Fitech was of no help, they no longer answer the phone when I call and do not respond to my emails. I had hoped to go to there location in Riverside, ca but with all the other problem on this trip I didn't make it.

As I said I think an exhaust leak and air intake temps may be the problem as well as no tuning skills.

So for the trip home I removed the EFI system and reinstalled the edelbrock carb. and drove home without a problem.

 

My take from what you said that vapor lock would be something I would look into. It would explain what you have been describing

 

Possible, but I would think the fuel pressure would have dropped. It usually stayed at or near 55 psi Which is the preferred pressure for Fitech

But this is one of my questions, is the intake air temp too high? one wonders

 

Without a log of the engine in use, how is anyone to know? Can you log the engine operation and post the results. Without seeing the conditions of operation, everything will be nothing more than a guess.

 

I did do logging, I will try to get my son to get the handheld off the Jeep dash and upload the data.

 

This is a .csv file which I zipped. On line 268 the AFR trim numbers go Negative and just a few lines later the AFR goes to 20
DashBoard8.csv.zip
I opened it with Open office, and zipped it with Linux
let me know if you have problem, If so I'll use windows

 

here are other files
DashBoard9.csv.zip
DashBoard6.csv.zip
DashBoard7.csv.zip

 

If you've got an exhaust leak upstream of the O2 sensor, you need to fix that before you can expect anything to work right. If the O2 sensor is giving the ECU bad mixture signals, the ECU can't do it's job properly in closed loop mode.

 

I suspect an exhaust leak but the Fitech does not generate any codes

 

files 6 &7 are good runs, no problems
files 8 & 9 are bad runs
As I look at these I noticed every time the ARF goes to 20 the TPS drops to 0. and I know I was feathering the pedal to try to keep it running.
So can a TPS sensor work then quit, then work again when cool?

 

I looked through the 4 logs. Logs 6 appears to show better results. I also noted cooler air temp. Log 7 shows the engine running in a lean condition which is a problem. Log 8 shows an issue with the TPS. Is it faulty, circuitry faulty or an issue with the setup. I'm not sure what the problem is but there is a problem that needs to be addressed. Log 9 shows the engine running lean at higher rpm's returning to a rich state as the rpm's return to idle. The log also show the system does not like higher air and engine operating temperatures.

Not normally. If you can, using your hand held controller, with ignition on, engine off watch the TPS while using the throttle. Do the numbers change in a smooth manner or are they erratic?

Not sure why you say this. The logs do not appear to show that as often times, the engine is running rich. If you haven't I would weld the o2 bung into the exhaust and not use the clamp on assembly they send.

I'm thinking there is a setup issue with the ecm. Knowing from your earlier posts, there were quite a few problems getting the system to function as the instructions describe. It certainly isn't self tuning. If it were me, I would slowly and methodically go through the setup again noting results of each step. Write it down. If something malfunctions note that in detail. If setup works correctly proceed with your driving tests with logs for evaluation.

You said Fitech isn't responding to you. Did you purchase the system from the manufacture or a distributor. If from the manufacture and problems persist, I would email results in a precise detailed manner without angry comments or whining. No need to give them an excuse to continue to ignore you. If purchased from a vendor, that maybe a route to request help. Another potential source for help maybe a local vendor as the manufacture lists several in PA. If any sell and/or install the systems, they may be willing to to give some assistance.

 

Well, I have to apologize, I wrote a response to 45es but it didn't post. The TPS signal is smooth. I bought the Fitech unit from Summit Racing in 2017 and installed in 2019. Fitech did help get it up and running, and helped get my hand held unit up to current firmware version.

I sent the files shown above to their tech support on Monday with an nicely worded email requesting any advice they could offer and asked if they have a tuning service at their facility, and that I would be willing to pay for....... Saturday and no response except for an auto generated email.

 

Vapor lock is the boiling of the fuel in the lines and pressure would not be indicated lower but lift the hood and engine cools off and will then stat again. Albeit today’s modern fuels are more prone to vapor lock and that is why fuel pumps are almost always inside of gas tank where the fuels acts as a heat sink. Just a thought

 

I have a lot of experience with a completely different gorilla, so as far as tuning your FiTech goes , I am probably of no help. Hell, in my system , one has to make sure all electrical , particularly ground connections are good & clean ?

If I may ask: why do your vacuum #'s log as negative ?

 

I have no Idea, with no help from Fitech most of these numbers are greek to me. This is why I am looking at using a Chevy 350 tbi from my 95 chevy van. the computer work is done and operational.

 

Yes Sir. You would have to use the chip or the entire ECM from your ' 95. Everything goes through the ECM.

 

Yep,
Full wiring harness & ecm removed.
One of the obstacles to overcome is the speed sensor. I'm trying to find a module to attach to the dana20 mechanical output that has a thru ability for the speedo cable and a signal for the ecm