Should have reread scan tool first, Long term goes to -77 after install not plus. Plug the original ECM back in and readings go to a normal readings.

 

Larry- your STFTs indicating your ECU adding between 14 and 17% on both banks. If these numbers are to be believed it would indicate you have a vacuum leak upstream, something common to both the front and rear bank. How far have you driven the car with the ECU plugged in? Have you driven it far and long enough to see if the LTFTs will reset to indicate the STFT average?

 

Larry- let me clarify. The STFT readings may be correct and the readings are just different from your original ECU. I swapped in 3 different ECUs while testing my piggyback controller configuration and all STFT readings were different among all 3 of them. Was the car at normal operating temps when you took the STFT readings? I'd run the ECU for a couple days to see if the LTFTs reset and display a reading reflective of the STFT averages.

 

Bob, The original ECM long-term readings are about 5% plus and the short term values float 8 to 12 % in either direction of 0. The scan tool readings we have been looking at are after three 10 mile road tests of the spare ECM. The long term values never really changed from the first road test. I have tested both intake and exhaust manifolds for air leaks with a smoke machine including the new catalyst. Same readings with either S/C air mass meter I own or either sets of injectors. The compression is 180 across the cylinders. TDC on cylinder #1 set with a dial indicator/ Cam timing set and rechecked three times with factory tool. Fuel pressure 49 lbs Key on, Engine off. Key on, Engine running FP drops 5 lbs. Sufficient fuel volume test. Injector pulse fully warmed up is 2.8ms at idle. The idle speed control valve works. Super charger intercooler reworked to be stand alone with oversize pump, reservoir and intercooler at 110 degrees F at high way speeds. Oversized Super charged crank shaft pulley installed. After three road tests I reinstalled the original ECM, Performed a hard reset, Rechecked the TPMS switch, Full throttle position and O2 orientation. Every thing back to normal. I am convinced that some day I should swap chips between ECM's, and see if the fault moves with the chips, Hence my interest in reading, writing some new chips and maybe I can save this spare ECM or learning to tune the old ECM.

Thank You.
I don't want steal your thread.

Larry Louton

 

Larry, don't worry about stealing my thread, we are all just trying to help each other keep thee machines on the road. AEM did respond telling me the square wave output is normal and the jag ecu should "trigger" on it; I've impirical evidence the Jag ECU only likes it up to 2500 RPMs. Hey, look what I found in my junk drawer at work? I remembered having to flash the cross-point settings on an old audio/video router I used to own in the 90's. Any time I moved a cable or added a video tape machine I had to alter the router's config file and burn it to the eprom. I need to find a power supply that will work, located a USB to DB9 serial converter then a DB9 to DB25 printer adapter to connect to the eprom burner. Once I gather the necessary items I'll try and read the eprom and save the config file from my SC ECU (6.9 LTFTs). If I'm successful, maybe I can write my file to your eprom?

 

Your idea about the cable adapters caught my interest in the way that I wanted to go. I found a thread from Lady Penelope about a Eprom reader/ writer, programmer that the seller on E-bay, Item #290924359652 claims that the software is very easy to use but the cable included was a 25 parallel port printer cable from which only very old computers still had such a port. So if I find these cables USB to DB9 serial converter then a DB9 to DB25 printer adaptor cable or is all I need the DB9 to DB25 adaptor to go to the back to my Panasonic Toughbook CF-18? I am going to contact the company to see if your plan will work. Still will have to contact
JLREngineer to see if he will teach/show me how to read/ rewrite maps for these old cars. All my interest in the 95-97 XJR came from being a Jaguar line technician for 31 years and liked this engine/ drive line the best. But I liked the Series Three bodylines more then the X300 line so I put the XJR engine/ trans into the Series Three sedan. Enclosed are a photo of the back plug of my old laptop and a picture of my car.

 

I like the engine swap to that body style. It looks like your older laptop already has a DB9 comm port, no need for a USB converter. All you need is the DB9 to DB25 adapter and you can connect to the older EPROM burner with a DB25 printer cable. In reality, most printers have a parallel input and a serial input (DB25) The DB25 it is an RS-232 serial connection just using pins 2,3 and 5; sometimes pins 2&3 are straight through and sometimes they are flipped (null modem). No doubt you can find the manufacturer's software to connect, download, edit and flash changes back to the EPROM; I just used Notepad to edit. Do not use a text editor like Word, it adds hidden special formatting characters that can mess with your file. Also make sure you've no extra spaces at the end of line breaks; spaces count as characters and can also mess you up.

 

Hello Bob, Contacted the company about using a adaptor cable and they said no it won't work. ( They said that my port is a serial port, Their programmer needs a parallel DB25 pin LPT port). Then I asked if they had a programmer to more fit my needs and they said no. Not wanting to go chasing around for another computer of any sort just for a printer port, I went to E-bay and found item # 263688759180 which seems to fit my requirements. If you have some time could you check it's abilities so I can learn with a proper tool to start please. If then, I can use this laptop or the old Panasonic to learn with. I am going to start contacting JLREngineer to find out if can get me up to speed with what I am about to learn.

Thank you

Larry Louton

 

That should work fine. If you like the other EPROM burner better this https://www.officedepot.com/a/produc...B&gclsrc=aw.ds is also an option.

 

I went with the E-bay version. Hope the instructions are in clear English. My thought was the tool has such a old connecter on it, How old is the rest?

Thank you.

Larry Louton

 

Hi Larry and Bob,
I salute both you guys and your respective projects.

Bob, unfortunately I can't offer any advice on why the GEMS ECU won't accept your square wave input. I appreciate that you are enjoying the intellectual challenge of getting your piggyback ECU to work. However, I can't help thinking it would be easier just to fit the MAF, injectors and ECU from an XJR, and start enjoy driving the car, rather than be struggling to get the piggyback ECU to provide a cranks sensor signal which is acceptable to the GEMS ECU. The injectors from an XJR6 engine are sufficient to make 400bhp. The MAF can only measure 1018kg/hr airflow. However, unless your turbo exceeds this value, then the level of enrichment won't be reduced. The AFR at high speeds is mapped to about 10.5:1 to limit steady state exhaust temperatures. You can afford to saturate the airflow meter quirte a lot before the fuelling gets leaner than an AFR of about 12.5:1 for max performance. What I'm saying is that you don't need a piggback ECU in order to build a driveable turbo Jaguar AJ16 engine.

Larry,
From your posts are you saying that your XJ6 series III now has sensible LTFTs and STFTs on one ECU but not another. If so, why not just stick with the one that works, and ignore the other one?

 

Hello Bob, I got my programmer and am in the midst of learning how to save and read the chips of my spare -77 LTFT ECU while I have company down from Michigan. First I have to learn how to read, save before I can write.
Feels like I am back in grade school again. Contacted XJR Engineer and he gave me some ideas about the mechanical systems of the engine I should review before doing any chip work. Was reviewing this thread and saw the part about the square sine wave from the CKPS. Can you use the CMPS signal for your rpm signal instead just to operate the piggyback ECU?

Larry Louton

 

Hello Bob, I was rereading this post for review and saw that the CMPS signal idea had all ready been mentioned before. My news is that the lean condition problem on both banks has been solved. I had the engine running with the air cleaner removed while monitoring the O2 sensors with a voltmeter. The scan tool was reading STLT values next to the voltmeter and I said to myself, This weird, The ST values are flipping/ hovering from -5-8% to +5-8% just like they were supposed to and the O2 sensors were rising and falling 0 to 5 volts instead of hovering around .15 volts at idle like it used to. Turns out that it wasn't low fuel pressure or a vacuum leak or any of the usual lean conditions.
My air cleaner had a obstruction just before it's inlet causing a restriction in air volume at all engine speeds. Had a lot things to do to get another type of air cleaner moved in but it's over now. XJRengineer had a quote about this kind of subject matter when I first told him of my vehicle. As in any marriage or union, there has to be a lot of gives and takes to make this work well. The Long term values have dropped a little bit but I haven't taken it out for run yet, But the Short term values are just acting too good to be true. Anything good happening with your turbo project?

Larry Louton

 

Larry good news on the fuel trims and thanks for following up on my turbo project. I'm running the supercharged ECU and 36lb XJR fuel injectors in my NA XJ6. Because I've not installed the turbocharger yet I'm using the AEM piggyback controller to remove about 45% fuel across the board. I'm discovering the piggyback controller has its limitations in that I can not control timing, boost cut and a number of other inputs and outputs so I've purchased a Haltech Elite 0750 stand alone ECU. Though it's designated "stand alone" I will run it in conjunction with the factory ECU. I'm busy building another ECU harness adapter to support the Haltech ECU; the harness adapter allows me to easily default the car back to the factory ECU. I'm also looking for an oil feed/source for the turbo and I'm debating whether or not to tee the pressure switch or leverage the oil galley pipe plug on the other side of the oil filter, opposite the oil pressure switch. The oil sender switch has 1/2-20 threads with a sealing washer; I've found a couple of 1/2-20 tees but none have a sufficient shoulder for the sealing ring; I may have to fabricate one or use the other oil feed. The other oil feed has what looks to be a 1/8 pipe thread; maybe just screw a 4-AN adapter in it and call it good. the turbo oil return will be a 10-AN hose and hose fitting back to the oil pan. Lots of work but hoping to make 450hp @ 8lbs of boost; at least once

Take care,

Bob

 

Hello Bob, had similar problem on my AJ16 SC was how to plumb a switch and gauge to a engine that only had a gauge before. I used the aluminum block, Banjo bolt and seals from the Jaguar 4.2 engine that came out of my car.
If you have a jaguar junk yard near you, Remove block, banjo bolt, seals and switch's to use at your pleasure. The banjo bolt is the same size, thread pitch as the sensor coming out. I reused the seals and this set up has given me no trouble at all except when I replaced the starter for noise.

Larry Louton

Just to rear of oil filter

 

Larry- great idea! Sometimes it just a matter of perspective... I was going to fabricate something a lot more elaborate. I'll still probably fabricate this assembly (a cross-drilled block with threaded 1/2-20 ports) far less complicated than the "street tee" I was originally going to fabricate. Thanks for sharing!

 

Bob, Been going back and forth with my two ECU's. Performed TPMS, Kick down and O2 sensor reorientation programming with different results on each ECU. Even after road testing three times each and allowing to idle the Short term fuel trims on both will float plus or minus 5% to 8% but the Long term seems to be stuck on plus 31% on my original ECM, but the spare ECM seems to be stuck on minus 82%? What I am wondering is if I was to install my spare ECM and program it with a different VIN # what would happen? Do you have the last six of your VIN# of your S/C ECM? I am trying to change the file and change the result of the Long term starting point. I don't have the VIN of my spare ECU to help my self and inputting the my VIN could maybe be my whole problem with my spare. I have been able to open and store the big chip of my spare ECM but the small chip no matter how I try to work around it, I get a chip error fault message. The big chip reads like Greek to me any way's. There is a website for the uneducated that I have been working with but they are working on Honda's and don't know yet if I should go that way.
I am probably going to have to go with XJREngineer in the long run to solve my riddle. Maybe having some wild Long Term starting point is the norm for these old cars. Last six of your S/C VIN# please if you have one.

Larry Louton

 

Larry- I'll check my eBay order for the supercharged ECU to see if the seller listed the car's VIN in the listing; I'll let you know later this evening. Wait a second... If I connect my Jag IDS software maybe it will report the VIN from the ECU! I bought a desktop PC with a parallel port to run my chip burner but have not played with it yet because the factory ECU now relegated to just satisfying the "check engine" light. My Haltech ECU now tasked with the heavy lifting. Question, are the 2 IC's the same chip model number? On my burner I have to specify the chip model number before I can successfully perform a read/write operation.

Bob

 

The one chip that reads and I can make and copy the file is a 32 pin, the one where I get a chip error message is a 28 pin. There is a drop down menu of sorts that you read the manufacturers name and part # then click on the read button. The Honda forum talks about a file name that can be imbedded in the chip that if you don't know how or where to by-pass you will get a chip error message.? I don't know yet if a different VIN# will bring up a different file to do the O2 orientation with. Might be the reason that when I program my spare ECM with my only VIN # that it throws the STLT term scale right of the planet. Don't know the VIN of that one either. The long term number started out at +lean 39% and has slowly dropped to +lean 30% in the last week of my known VIN ECM. It's going slowly finally in the right direction at least. Might be the price I pay for not correcting the condition sooner


Larry Louton