• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

No Spark with recently swapped in engine

basalt51

basalt51

NAXJA Member #761
Location
Woodland, CA
I finally finished swapping in a 2000 longblock into my '97. Used everything from the '97. I don't seem to be getting an spark from the coil, but the coil tests good. I am also thowing code 11 - Faulty CPS.

CPS is brand new from the dealer. TPS, coil, dist, etc are also pretty new.

I tried testing the CPS. The ohm meter read "-", which is its symbol for infinite I believe.

Any suggestions?

Will unplugging the CPS and cranking it tell me anything?
Should I just reinstall the old CPS and see what happens?

Is it possible to install the flex plate incorrectly with regard to the CPS? I'm 90% sure I installed it in the same orientation as on the old motor, but maybe not.

Thanks.

Oh, '97, 4.0, AT
 
Maybe somebody can chime in, but on the earlier CPS's, they are not supposed to read infinate. It is somewhere around 200 ohms. Maybe the later CPS's are different, but I doubt it.
 
From alldata for '97:

PROCEDURE

Place an ohmmeter across terminals B and C (SEE Image). Ohmmeter should be set to 1K-to-1OK scale for this test. The meter reading should be open (infinite resistance). Replace sensor if a low resistance is indicated.
 
Thanks Basalt, I guess I learned something today. The early cps's are a coil type and the later are a hall efect type. Go figure.
 
Another question about the Flexplate/CPS intereaction. Another exerpt from Alldata:

Vehicles with Automatic Transmission:
Install the converter-to-drive plate bolts.
Ensure the installation reference marks are aligned.

Are these "reference marks" the ones I was supposed to put on the flex plate/torque converter when I removed the engine? I did, they were just hard to see and the Torque converter/flex plate may not be exactly the same as before. Will the tranny/Flex plate being out of alignment cause the CPS to read incorrectly? Or is this simply to help with balance?
 
The bolt spacing on the flex plate preclude installing it at the wrong indexing.
 
i am having the exact problem on my 89 i swapped in a 96 motor and now no spark everything was good before and i used all the same stuff i replaced the cps and still nothing i need some help to i am reading positive voltage on both sides of coil during engine on and crancking
 
When I swapped a 97 engine into my 90 I managed to break the wires on the CPS. There is an updated CPS wiring harnass available from the dealer. It plugs right into the computer.

chris
 
Another quick question:

My old CPS is part number 56027866AB

The new one the deal gave me - 56027866AC

Difference? I see parts stores listing both aswell.

Gonna go swap em see what happens.
 
WOOHOOO!

Put in the old CPS and it fired right up. The "new" CPS, has a little portion of the plastic part ground away, and the metal mount part has a nice little twist to it. I'm not sure if the twist was there to begin with or not, but it had some alignment issues apparently. Runnin good with good oil pressure. A few vibs that weren't there before, but I did switch to M.O.R.E rubber mounts, so I'm hopin thats the cause.

One thing I"m not sure of, is if on '97 (or any year) the plastic dust cover is need for propoer CPS spacing?











$%#$%@# JEEP. :D
 
i was going to say, can you adjust the cps in the hole? i forgot. i do alot of voyager trans and you can set the depth. then tighten the bolt down. cant rember on the jeep. it cant be to far away or it cant read. to close and bang which you know now. we some time have a problem here in sweden with thouse cps if im right its because it gets so cold they crack after awhile they damaged
 
That would be good to know. The manual says use only the supplied bolts because they are made to space the CPS correctly. However, I have no idea how they could possibly be any different. :dunno:
 
You must log in or register to reply here.

Similar threads

J
Cranks, Fires, Dies - 1991 Briarwood Restoration
Replies
17
Views
3K
Jam Master Jay
J
S
98 XJ manual ignition problem
2
Replies
20
Views
4K
SurplusFan98
S
Xtreme XJ
Crank, no start even with new CPS...
Replies
13
Views
2K
Xtreme XJ
Xtreme XJ
J
Sudden Crank/No Start condition - also no accessories in On/Run?
2
Replies
22
Views
3K
RCP Phx
R
W
No Spark
Replies
6
Views
1K
Runnin'OnEmpty
R
Back
Top