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Renix crank no start

ljobbins

NAXJA Forum User
NAXJA Member
Location
SD County
88 stock engine ax15 trans

Was running rich but perfect then no start. Cranked for a while and started once more. Drove two blocks to my friends house and now no start. I had a pile of parts I wanted to swap to improve reliablilty and mpgs.

List of parts/things done:
New tps from napa one week before problem adjusted to 17%
IAC port cleaned one week before problem
Throttle body cleaned one week before problem
Grounds refreshed one week before problem(all grounds)
Now:
New CPS(thought was the problem since the old measured .35v) tests at .5/.51v
New ICU
New Distributor cap and rotor
New O2 sensor(was running very rich before
Verified spark to distributor cap and all cylinders
Verified fuel pressure with key on and cranking
Verified both temp sensors are good last week

So once again, it ran perfect and never died. It just stopped turning on. It cranks strong. With spark and fuel pressure what else? I can't imagine every fuel injector clogged at once. Help please
 
Eliminated ballast resistor and I have full fuel pressure with key on and while cranking. It has to be a spark issue or lack thereof.
 
Is your map line connected to the throttle body correctly? An engine won't start and if running will shut down immediately if the electrical connector is out or if the tube going from the map to the TB is cracked or disconnected.
 
One other consideration, do you have a Power Latch Relay in your rig? if you do, you should be able to get power to the fuel lines but no spark when you try to start it if the relay goes bad. You could snag the AC relay or O2 sensor relay and swap quickly to check without any issue as they are identical.
 
so you've verified fuel pressure at the rail and spark at the plug. You should also verify the injectors are firing (use noid light).

also suspect it may be flooded. Try cranking with accelerator to the floor (not pumping, held at WOT). This will turn off the injectors and allow the motor to clear a flooded condition.
 
So I didn’t have time to work on it yesterday and my next chance is Tuesday. I want to see if I can move the cps closer. I will check the injectors. I will check to see if it’s flooded. A guy told me that it could be a bad pick up sensor in the distributor. Is there a way to test that? And if so, is that a stand alone replacement or part of the distributor assembly? Thanks
 
A bad Cam sensor in the dizzy will not keep it from starting. CPS at .50 volts (if the meter is accurate) is more than enough.

You do or do not have spark???? Renix is easy to flood with a no spark!!!

No spark, no fuel injection, flooded, or timing on the dizzy/timing chain....
 
Update.

I verified .5v at the new cps. Verified everything and still no start. A friend knows a mechanic that knows jeeps and he came over and found the smallest piece of melted plastic on the middle contact of the distributor cap(between the cap and the rotor). Said that’s most likely the problem. Still no start. So just to see what happens we swap the original cps back in and it starts instantly but dies with gas. Verified fuel pressure to be correct and all other sensors perfect.

So could my old cps be bad and cause the erratic idle and die with gas applied? And could the new one be bad but still register .5v on the multimeter?

So just to recap. It ran perfect then just didn’t start.
New o2 from horrible mpgs
New cap and rotor now
Verified spark on all cylinders
Verified fuel pressure is good and all injectors firing
TPS new from Napa from delayed and erratic acceleration (prior to problems)
Grounds refreshed
 
The only sensor I have never replaced is the map because I believe in trying to keep original parts on if I can since they don’t exist anymore. I have tested it a few times and I verified the vacuum line is clear and has a good connection on both sides. However I want to tap the throttle body to get a better connection or at least in my mind it will be better.
 
It's kind of a pain to get at, but you should check to see if your ignition switch is burnt out. When I had a crank/no start with fuel and spark condition, that's what it ended up being.

It's midway down the steering column, up underneath the dash.
 
Maybe two problems. If the IAC is not set right it will not start, as it is starved for air, or gets too much. Thus a sticking IAC or B+ relay problem.

Dying when you give it gas sounds like a different issue, problem #2. Try flooring it to WOT when cranking, that will dry it out of it flooded. Make that a routine!!

I'd check the fuel pressure running and as you give it gas!!!! The FPR is vacuum operated and changes the fuel pressure when you give it gas, if the FPR leaks fuel into that vacuum line it is bad!!!!

You may have fuel pressure when cranking but how about when pressing the gas )got to get it running first).

You could have a weak spark!!!! Low voltage to the ICM/HV coil!!!! Or a bad ICM?
 
First off, since you have been trying a while, you may have wet fouled the plugs. Renix is really finicky about that. I would get the cheapest set of Champions you can get and swap the plugs. Make sure you are getting a nice fat spark at the plugs. If you are getting a good fat spark, then the CPS is good and very likely the coil as well.

It is a long shot, but the Cam Position Sensor in the distributor could have it firing on the wrong cycle, but you should still at least hear some popping.

Borrow a NOID light at Autozone and check for electrical pulses at the injectors. Do you smell gas in the tailpipe? With all that cranking, you should. A cheap test is to spray some ether starting fluid or carb cleaner down the intake when cranking. If it fires, you have a fuel problem.
 
It’s starting now and running for 10-20 seconds at a time. Idles fine for a few seconds then starts a slow surge to drop until it dies. I have had a bad iac once and it doesn’t do the normal fast surge. Fuel pressure is 35 at idle and jumps to 40ish with a fast opening of the throttle. Fuel pressure never drops.
 
It’s starting now and running for 10-20 seconds at a time. Idles fine for a few seconds then starts a slow surge to drop until it dies. I have had a bad iac once and it doesn’t do the normal fast surge. Fuel pressure is 35 at idle and jumps to 40ish with a fast opening of the throttle. Fuel pressure never drops.

Put a vacuum gauge on it. You may have a plugged CAT.
 
Also make sure the distributor shaft does not move side to side or rotate, It should be tight (bearings and drive gear..). Old_man has great suggestions too!!!!

But I think the newer NGK plugs are better. But even crappy brand plugs should fire and start.

Vac gauge would tell you if the Cat is plugged, once it runs for 10-20 seconds.

Have you checked the B+ relay yet, and contacts....it trips a timer that lets the ECU reset the IAC for the next start. It is critical for the IAC-crank-start cycle
I think Cruiser54 has a good write up/images on this
 
I’m in Baja and I’ll have to run up to the USA in the morning to find ngk plugs. I have had better success with them as well.
 
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