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Dropping an aw4 into a *gasp* TJ, what flexplate?
- Thread starter 4ward
- Start date
- Location
- Desert Beach So Cal
Any results?
The RENIX tone ring has lots of holes (three sets of twenty short slots, separated by long slots, IIRC), and the HO tone ring has only a few (three sets of four notches). The tone ring on the flexplate must match the CPS and MPI system (and yes, the RENIX CPSensor is a different technology from the HO CPSensor).
IIRC both 999 and AW4 use the same four bolt TC pattern. Early YJ's (97-90) came with Renix tone rings in front of TF999's (without MPI). All the HO XJ & YJ flexplates are the same (but different than RENIX).
If the MPI is HO the Hesco/Mopar crank balancer CPS conversion is an option (costs $$$, but the trans does not have to come out, ... again).
The RENIX tone ring has lots of holes (three sets of twenty short slots, separated by long slots, IIRC), and the HO tone ring has only a few (three sets of four notches). The tone ring on the flexplate must match the CPS and MPI system (and yes, the RENIX CPSensor is a different technology from the HO CPSensor).
IIRC both 999 and AW4 use the same four bolt TC pattern. Early YJ's (97-90) came with Renix tone rings in front of TF999's (without MPI). All the HO XJ & YJ flexplates are the same (but different than RENIX).
If the MPI is HO the Hesco/Mopar crank balancer CPS conversion is an option (costs $$$, but the trans does not have to come out, ... again).
CheapXJ
NAXJA Forum User
- Location
- 570, 813 or 303
you need:
99 XJ 4.0L auto crank sensor
XJ flexplate 91-01, the tone rings are all the same.
the renix flexplate is your big problem.
99 XJ 4.0L auto crank sensor
XJ flexplate 91-01, the tone rings are all the same.
the renix flexplate is your big problem.
BrettM
NAXJA Forum User
- Location
- michifornia
i think the CPS he has will work, but definitely the renix flexplate won't work. even if I'm wrong about the CPS, might as well try it with the TJ CPS before going out and buying an XJ one.CheapXJ said:
4ward
NAXJA Forum User
- Location
- Dayton, OH
We've got a TJ flexplate coming. It'll be here on Sat. I know it will work with the cps, and I have the technology to punch new holes in it if needed.
Jes, this is pete's junk. We're probably taking it up to the Werock comp in July as a recovery vehicle. Although it may need recovered itself :laugh3:
Jes, this is pete's junk. We're probably taking it up to the Werock comp in July as a recovery vehicle. Although it may need recovered itself :laugh3:
Slip Kid
That'll buff right out
- Location
- A cornfield in IL
Renix wiring needs the early flexplate. The hole pattern is differnt, the cps needs the proper flexplate.
4ward
NAXJA Forum User
- Location
- Dayton, OH
The 999 tc and the aw4 tc both have a 4 bolt pattern, but the 999 pattern is about 1/2" larger. Looks like I'm drilling holes. I went back over the writeup that Stu's buddy did and it does mention the xj flexplate in the parts list (completely missed that one). We're going to see if the dealer will swap them out for us, if not I'm drilling it. We did get the shop discount at the dealer though, saved us about 50%.
Brink
NAXJA Forum User
- Location
- Sylvan Lake ALberta
Did you get this working? I'm having problems with an AW4 I've put in my TJ also.
It'll start and run. But lacks power and smells rich.
It'll start and run. But lacks power and smells rich.
I just had the same problem... I got a Renix flexplate when I swapped in an AW4 into my Sufa. Since I live in Israel and getting Cherokee parts is difficult and expensive, I built a little circuit that tricks the ECU to think it has the right flexplate. It works very well.
Here is the theory - the HO flexplate has three sets of four notches. The ecu sees three sets of four pulses from the CPS when the engine turns. The ECU syncs up on each set of four pulses, and figures out where the TDC is based on the fourth pulse in each set.
The Renix flexplate produces three sets of 20 pulses, 19 of which are shorted and 1 is longer (at least 6 times longer). The ECU syncs up on this pattern and figures out the TDC.
The circuit I built contans a small FPGA. It received the pulses from the CPS that senses a renix flexplate and syncs up on the 60 pulses. It differentiate between the large pulses and the short pulses, and figures out where the TDC is. Then, it generates a synchronized signal to the ECU with three sets of four pulses and the correct timing. The ECU receives this signal, "thinking" it comes right from a CPS that sniffs the right flexplate, and generates the correct timing (injection and ignition).
I'd be happy to share that design if anyone interested. The total cost of parts is about $30, but it does require some knowledge in electronics and programmable devices (FPGA).
Oded
Here is the theory - the HO flexplate has three sets of four notches. The ecu sees three sets of four pulses from the CPS when the engine turns. The ECU syncs up on each set of four pulses, and figures out where the TDC is based on the fourth pulse in each set.
The Renix flexplate produces three sets of 20 pulses, 19 of which are shorted and 1 is longer (at least 6 times longer). The ECU syncs up on this pattern and figures out the TDC.
The circuit I built contans a small FPGA. It received the pulses from the CPS that senses a renix flexplate and syncs up on the 60 pulses. It differentiate between the large pulses and the short pulses, and figures out where the TDC is. Then, it generates a synchronized signal to the ECU with three sets of four pulses and the correct timing. The ECU receives this signal, "thinking" it comes right from a CPS that sniffs the right flexplate, and generates the correct timing (injection and ignition).
I'd be happy to share that design if anyone interested. The total cost of parts is about $30, but it does require some knowledge in electronics and programmable devices (FPGA).
Oded