Hi all,

My jeep started yesterday no issues… today replaced all my cables with the jeep cables big 7 upgrade. Finished it up, getting power to jeep, cranked it and wouldn’t start. It’ll crank and crank and crank but won’t start. I replaced a few eeeks ago my CPS (Amazon one, they don’t make oem one anymore) and my tps from advance auto parts. Anyone have any idea what it could be? It’s a 90 jeep xj renix 4.0, auto. It started yesterday, but today after doing the big 7 upgrade it won’t start. It’ll crank but no start. Any help would be appreciated.

could it be my battery? Even tho it started yesterday before the big 7 cable?

 

Big suspect to me is grounding. Check all of your grounds and clean up any surfaces where you attached the cables. Could have had corrosion around the old cables and when you removed them and installed new ones didn't get a good connection.

 

ty for reply, so I tried cleaning all contact points, one on firewall… one on engine block… and then one on fender which is now a new cable, my renix did not have a fender ground originally but I added it since upgrade came with it. But I tried starting it with the fender one removed in case that was issue still no start. I’m not sure if there are any other ground spots for the renix… only ones I replaced where firewall to cylinder head… and battery to engine block. Went to NAPA to get a new cps but didn’t have in stock have to wait until tomorrow. I’m thinking maybe my cheap Amazon cps subsequently went to ****. I’m not sure if it’s my battery as it drained completely after trying to start after 3-4 times… have hooked up to charge right now. I think battery is 3 years old… might replace it also tomorrow

I also tried starting it with starting fluid in intake… thinking maybe I’m having a fuel issue but didn’t start still after many attempts…

here are photos of my grounds, I reverted my firewall one to the original one because I read somewhere to not replace the weaved one with wire…

 

Did you get all the other wires back where the ground wire to the block connects? A couple of important things ground there like sensors, fuel injectors, etc.

 

I didn’t see any other wires nor were anything else connected when I removed the engine block ground… do the renix jeeps have these?

 

So update, I had the battery on the charger/tender all night. Woke up hooked it up and jeep started right up. I’m going to assume my battery Has gone to crap?

 

http://cruiser54.com/

See if you bumped something in the process.

The CPS can be tested and modified for higher output.

Just for fun, unplug your CPS connector and plug it back in.

 

honeslty I was very careful doing this because I know how fragile a lot of the wires/sensors are with a 32 year old jeep and 260k miles. I’m not sure if it was the CPS, I did unplug it for an hour or so last night. It could be my CPS… I bought some cheap Amazon one since mopar doesn’t make it anymore. Any recommendations where to get OEM like quality sensors? I went to Napa but they didn’t have it in stock… so I ordered one for $40 thinking my CPS went to ****. But now the jeep started… after charging the battery all night. My battery is 3 years old… would a weak battery cause crank but no start?

I have used your website cruiser I’ve used it to diagnose a few things I want to try and more stuff done but one step at a time.

can you also recommend where to get oem quality parts for the renix jeep? Since mopar doesn’t make most of it anymore… advance? Orileys? Napa? Or any other online stores?

 

Looking at your picture, I wonder if someone moved the engine ground. It's normally at the dipstick mounting bracket with a bunch of other smaller ground wires. The ignition module on the Renix won't fire if the battery voltage gets too low. I too have found that unplugging and replugging the CPS can magically fix it. I assume that's because the Renix CPS is pretty sensitive to resistance in the wiring and this refreshes the connector a bit.

 

On my '88, if the battery can turn over the engine fast enough (not fresh battery) it will usually start. I don't what the voltage threshold would be for it to fail. Given your battery died after a few attempts but started right away after charging suggests that part may be the battery. I read somewhere that a battery tends to die at "warranty period plus 1 day". Check your charging system.

For parts where I can wait a few days, I use Rockauto. I tend towards NTK or Standard Motor Products for sensors.

 

That’s what I was thinking, since it is to the right of the passenger motor mount. I checked the dipstick mount and didn’t see any other wires… so I’m not sure what previous owner did. I do think my battery had gone to crap and caused the issue… since today after charging battery all night cranked right up. Trying to find a good quality battery to replace it With.

that’s my understanding as well I didn’t think my battery was dead yet, but guess it was since after 3 cranks it completely died…click click click. I charged all night and cranked right up. Looking to find a quality battery. I will try rock auto, I usually like to be proactive and buy things in advance and get things replaced before they fail. I hate to be stranded I will check NTK. Thank you


here is a better photo of you turn it to the side you can see better.

 

Test the CPS. Clean it's connector with contact cleaner.

You should have multiple small black wires at the engine dipstick stud.

 

The smaller wires come down from roughly the center of the wiring harness that runs across the top edge of the firewall.

 

Update… so I found those other cables there were 3 of them in the back on dipstick mount. Removed but, cleaned the contact points got it nice and shiny. I do believe my CPS that I installed from Amazon is garbage. 2 days ago jeep wouldn’t start… same symptoms, crank crank crank won’t start… killed my battery after bunch of tries…so charged battery. Tried to start just again crank crank crank, then I disconnected my CPS, waited few mins reconnected, and she started right up. Ordered a NGK/NTK CPS… can’t find any MOPAR oem, since mopar doesn’t make anymore. Read in a few spots and I think even cruiser posted somewhere saying NGK/NTK is oem or was oem quality so ordered when arrives will install.

 

Siemens was OEM for the CPSs. NTK for the oxygen sensors.
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