RENIX no start... no fuel...., no clue...

so first off, i delayed posting this thread for allmost an entire week while searching, and just passively reading every no start/dead jeep thread i could find... still clueless....

so a little background, 90 xj, auto. had a weird no start about 2-3 weeks back, typical cps-esq problem, crank forever, no trying to start, no allmost starting, no nothing. had it towed home, but when i got home 4-5 hours later, it started up no problem. i fixed a faulty ignition relay (the thing your positive batery terminal gets distributed at, next to the relays on a renix), assuming that was a problem (had some loose wires at the distro bolt).

fast foward 2 weeks later, and it left me stranded again. did the cps in the street... nothing.
had it towed home again (really looking into a AAA membership at this point)

at this point
at this point, it appears i have neither spark nor fuel, i cant get the fuel pump to prime reliably.... it does it sometimes and not others, not EVERY time i turn the key to ON. but if i jumper b+ to the ballast resister, i get a constand hum of the pump running....
ignition coil has been swaped out, new cap/rotor, new cps


im stuck, i have no idea whats going on, and it needs to get smogged this month, and considering its a DD, and only the 12th... it needs fixing, i beg any renix freaks in ear shot to show some mercy and help...

That "ignition relay" is the starter relay.

You said you tested the CPS(CKP) and got a zero reading or "nothing" as in it tested good?

The CPS(CKP) is a sure kill on the Renix. Before you do anything else renew all of the grounds and clean all cable ends. Grounds at the dipstick tube, the starter relay, the engine, the back of the head to the firewall.

i did check the cps, and got a 'NOTHING' reading...
i ran out of light today, and will be re-doing all the grounds tommorrow. i figured it wouldnt be a ground thing sinse it was completely out of random, but will tend to those ASAP.

Does anyone know anything about the ignition switch? the thing that attaches to the steering column? keep hearing whispers about that, but in all my time lurking here on naxja, i have read VERY, VERY FEW posts mentioning it...

coincidence maybe? but i recently had a parking attendant stir up an old intermittant problem with my key sticking in the ignition...

You should get 200 plus or minus 75 ohms at the CPS (CKP) with a hot engine. My FSM doesn't specify a cold reading, but do a search and you may find some additional info.

Please do renew the grounds first, our Renix have an electrical Achilles heel.

Also, what is your battery voltage, tested at the battery, when static? Voltage when cranking? If you are getting 9v or less when cranking the electronics are not going to work.

The ignition switch at the foot of the steering column can cause various problems when bad or just out of adjustment.

i did not think to get a cranking voltage reading.... static was about 12v. i will get one tommorrow, but it doesnt sound weak, and is a 3 month old red top.

is it possible the ignition switch is telling the starter to run, but not the ignition/fuel relays and everything else?

It could cause a number of problems, but don't just throw parts at it. Your battery can crank the engine just fine but not have the enough power. I love Optimas, but any battery can fail at any time, and it could actually be a poor alternator that isn't fulling charging the battery, or corroded cable ends, or high resistance from corroded grounds.

Three things that come to mind as "definite kills" on RENIX:

1) CPS. You said you've checked it - let's assume (for the moment) that it's good.

2) Power distribution. Since the OEM battery positive cable is not as well-sealed as it should be, you get intrusion of acid vapours and internal corrosion for the distro lead (the one that runs to the starter motor relay, and thence to various fusible links.) This can result in an intermittent connection, and is also a sure kill.

3) The RENIX Killer. Check/clean/replace the ground strap from the firewall to the cylinder head, as indicated. This is the single ground point that forms the "zero reference" for the various sensor readings that the ECU uses to manage the engine, and it is very much a confirmed kill.

Those are the first three things I'd check.

Here is a good link with info on lots of sensors, just scroll down the page to the CPS (CKP) section:

http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

IF it's cranking but not running, I'd suspect the CPS regardless. I'd also check the main fusible link for engine power.

Next, I'd start wondering about the Neutral Safety Switch.

IMHO. A bad NSS will prevent cranking, but cannot affect running.

winterbeater said:

IMHO. A bad NSS will prevent cranking, but cannot affect running.

Click to expand...

That's true, And when you have doubts, you can easy jumpwire it from out the starterrelay to ground yourself. :idea:

no fuel?

did you check the stupid balast resister to see if its failing, and the fuel pump relay?

the main 4 relays have been checked, i did the testing procedure from the renix fsm... went so far as to energize them w/ a 9volt battery, and check for continuity... everything passed..

as far as the ballast resister, that was the 1st thing bypassed after the cps replacement...

i tried starting it in neutral, but if it was the NSS, would it let the starter spin?
im going outside to throw some additional grounds on it in the next five minutes....

wim: i appreciate the diagram, but am having some trouble understanding it, are you saying to jump the 85 pin of the starter relay to ground, to bypass the NSS?

thanks everyone for the help, its been a long week

ok, checked out the fsm, and the starter relay isnt a typical relay... its the stupid power distro block thingy.... (having trouble finding a non pdf pic.... but it has a nut/bolt with a bunch of eyelets on it, attached to the fusible links...


i grounded the bottom terminal, to try and test wim's suggestion... no change...
also added an extra ground strap from a coolant line bracket bolt into the block, to the backside of the alternator (had less selection of eye-to-eye wire's then i though....)
off to go research testing fusible links...

starting to consider a kia at this point... (not really(

also noticed, my tach doesnt move while cranking..... im not sure if it does normally...

i do have ~11 volts while cranking...

You say you checked the relays, but did you check for current coming in to the "latch" relay socket. Later models this is the ASN, but I understand on RENIX it is the latch relay which I believe activates the coil and fuel pump relay.

xcm said:

also noticed, my tach doesnt move while cranking..... im not sure if it does normally...

Click to expand...

On my Renix, the tach indeed flutters while cranking. If yours doesnt, then Id say you have a spark issue.

ok, still have not been able to get this thing started... checked all the fusible links w/ a voltmeter, replaced and doubled up grounds.... i want to say i have 12v coming into the power latch relay, but i am not 100%, as i moved the relays around and now dont know which is which for sure....


any last ideas? 2nd round of things to check?

OI.

It sounds like you're going to have to buy a six pack of premium beer.

Get it cold.

Send me your address.


Some pizza might not fall far from the fix either.