Renix spark

[MJanky]

87 Comanche sport, 2.5, Renix ignition.

 

I've read that it doesn't send spark under 300 rpms. Anyone know some way to manually override it so that it does?

[gogmorgo]

Whether it dies or not, you're probably going to have oil pressure issues running it that low. Why would you want it to run below 300 rpm?

[MJanky]

I don't want to run it that low I want to be able to roll start it by myself without trying to push it almost 30 miles an hour. I just don't see how it can be bump started since there is no spark at low speed. I've heard of people bump starting their renix XJs and YJs but they must have been rolling down a hill or getting pushed or towed by another vehicle.

[gogmorgo]

What gear are you going for? The starter doesn't crank it over all that fast, so it shouldn't need to turn too quickly. Can't say I've ever bump started a Renix Jeep, but my Lada doesn't need much speed to get it running... The slope in my back yard only drops two or three feet over three car lengths, and from the top to the bottom was enough to start it every day for three weeks while I waited for a new starter to ship from Europe.

But back to your situation. Standard fare 2.5L/AX4, 4.10 ratio axles, 27" tire. At 5 mph, you'll be turning around 370 rpm in 3rd, 600 rpm in second. First is probably too low (pretty tall trying to push back the other way) but you'd be looking at 1000 rpm. How's that for overthinking a bump start? At 5mph I might go for second, but I think most sources would recommend 3rd.

Once you're rolling, don't just dump the clutch, bring the engine up to speed slowly, pretty much the same way you would taking off from a stop... it's basically the same thing, you're just using the the car to start the engine moving instead of the other way around. Giving it some throttle may help to avoid the engine-brakey feel/speed loss, then get the clutch back in once it seems like it's going and step on the throttle so it doesn't stall out.

 

Now I need to ask why you need to bump start your truck..? A reman starter isn't all that expensive, a rebuild kit is cheap, and you could likely get a working one at a yard for not too much either.

[MJanky]

Haha if anyone overthinks bump starting it's me. My Jeep starts by itself just fine but I really prefer to have an emergency method to get it going just in case.

 

In any event you sound like the right person to ask about it. However I've tried numerous times in all 4 gears and even reverse (pushing it backwards of course) and no joy. This was within a distance of about 40 feet or so and I'm sure I had it rolling at least 5 mph. I've started similar vehicles under the same conditions so I knew something was different about this one. Knowing how many times it turned over before starting with the starter led me to research that and learn about the renix deal. I might convert it to carb just to get rid of that. Then I think it would roll start easy. It certainly isn't hard to push by myself.

[MJanky]

Oh and about that Lada...I know some of those actually had hand cranks, so likely they are low compression engines that would be very easy to push start...much like a Willys Jeep with the Go Devil engine.

 

If trucks still came with hand cranks my worries would be over!

[gogmorgo]

I'll admit there is a learning curve to it, and at least the 4.0 Renixes need a few cranks to sort themselves out before they fire up, so that could be it. But I'm by no means an expert on Renix systems.

As to my Lada, yeah it's got the setup for it, the hole in the bumper and ratcheting crank nut (really just a regular nut with funky slots cut in it), but the crank handle and the rest of the tool kit was long gone by the time I got it. Haven't been able to source another handle to attempt the crank start, but it's something I'm keeping an eye out for. But it's true it doesn't seem like it takes much to get it started. I once left my lights on all day at work at -30, by coincidence the day I blew the line from the clutch master cylinder on the way to work, and there was still enough juice left in the battery to start it in gear.

[MJanky]

Yes the problem does seem to be the number of times the engine has to cycle before it fires with the Renix. I'm sure at higher speeds it would bump start fine but that's not going to work for me. And near as I can tell from reading about it there's nothing I can do to alter the way it works. I guess that's fine by me since I'm a carb guy anyway, I just have a really good excuse to dump the Renix now. I get the impression it causes a lot of problems when it acts up too so I'd just as soon not deal with it later.

 

Shouldn't be hard to find a suitable crank for that Lada if you don't need the original one. Hand cranks are pretty much all the same but there are 2 main types. Either the pin on the crank and the one way ramps on the engine or vice versa. They just come in different lengths and thicknesses but for a Lada most of the antique car or tractor ones should do the trick. I had a 73 VW Thing I set up to be hand started and I had 3 different hand cranks that all worked.

[Hammloaderman]

The starter went out on me back when I owned a 90 comanche 2.5 liter 4 speed and I could roll start it pretty easily by myself

[MJanky]

The starter went out on me back when I owned a 90 comanche 2.5 liter 4 speed and I could roll start it pretty easily by myself

On flat ground? Do you remember what gear you used? And approximately how much distance did you need to get it up to speed?

[gogmorgo]

Mm. The couple times I tried on flat ground even with a buddy pushing it didn't work out in the Lada. It almost always came down to just pushing it to a hill if there wasn't another vehicle around to assist. Fortunately hills aren't too hard to find, just run down into the ditch, lol.

 

Even a Renix fuel injection system is better in every measurable way than a carb. You'd definitely be making steps backwards by getting rid of it.

[MJanky]

Even a Renix fuel injection system is better in every measurable way than a carb. You'd definitely be making steps backwards by getting rid of it.

I'm a backwards kind of guy so that will suit me like a glove!

[gogmorgo]

Just don't expect it to solve your bump-start "issue"...

[MJanky]

If it doesn't there will be a carbureted Comanche for sale cheap!

[benjy_26]

Mm. The couple times I tried on flat ground even with a buddy pushing it didn't work out in the Lada. It almost always came down to just pushing it to a hill if there wasn't another vehicle around to assist. Fortunately hills aren't too hard to find, just run down into the ditch, lol.

 

Even a Renix fuel injection system is better in every measurable way than a carb. You'd definitely be making steps backwards by getting rid of it.

I've push started my 87 2.5 on flat ground too. Got it up to a brisk jog, jumped in and popped the clutch. I have an AX4, 3.55's, and 31's, btw.

[MJanky]

Thanks for the helpful info. When I get a chance I'll take mine somewhere where I can really get it rolling and try it. That's one thing I haven't done yet. Even if it works I still want to dump the Renix system though.

[benjy_26]

The Renix system gets a bad rap, I think. Once one catches up on all the neglected maintenance and some small tweaks are made, it's as reliable as anything else out there.

[Hammloaderman]

 

The starter went out on me back when I owned a 90 comanche 2.5 liter 4 speed and I could roll start it pretty easily by myself

On flat ground? Do you remember what gear you used? And approximately how much distance did you need to get it up to speed?

I always used first gear, never really had to get her rolling all that fast and yeah I could do it on flat ground, it worked fine in reverse too iirc

[cruiser54]

The Renix system gets a bad rap, I think. Once one catches up on all the neglected maintenance and some small tweaks are made, it's as reliable as anything else out there.

Correct.

 

Getting rid of it is like throwing the baby out with the bath water. 

 

An afternoon of tweaks and maintenance and you're good to go. 

[HOrnbrod]

 

The Renix system gets a bad rap, I think. Once one catches up on all the neglected maintenance and some small tweaks are made, it's as reliable as anything else out there.

Correct.

 

Getting rid of it is like throwing the baby out with the bath water. 

 

An afternoon of tweaks and maintenance and you're good to go.

 

The problem is that with a Renix you have more tweaks & maintenance to do the following afternoon and whenever the temperature changes or the sun shines.

[cruiser54]

 

 

The Renix system gets a bad rap, I think. Once one catches up on all the neglected maintenance and some small tweaks are made, it's as reliable as anything else out there.

Correct.

 

Getting rid of it is like throwing the baby out with the bath water. 

 

An afternoon of tweaks and maintenance and you're good to go.

 

The problem is that with a Renix you have more tweaks & maintenance to do the following afternoon and whenever the temperature changes or the sun shines.

 

Not true. 

[benjy_26]

 

 

The Renix system gets a bad rap, I think. Once one catches up on all the neglected maintenance and some small tweaks are made, it's as reliable as anything else out there.

Correct.

 

Getting rid of it is like throwing the baby out with the bath water.

 

An afternoon of tweaks and maintenance and you're good to go.

The problem is that with a Renix you have more tweaks & maintenance to do the following afternoon and whenever the temperature changes or the sun shines.

I'm sure you're being funny, but that's not really true. My tbi'd 2.t is just as reliable and hassle free as my 4.0HO ZJ and my OBDII XJ.

[cruiser54]

 

 

 

The Renix system gets a bad rap, I think. Once one catches up on all the neglected maintenance and some small tweaks are made, it's as reliable as anything else out there.

Correct.

 

Getting rid of it is like throwing the baby out with the bath water.

 

An afternoon of tweaks and maintenance and you're good to go.

The problem is that with a Renix you have more tweaks & maintenance to do the following afternoon and whenever the temperature changes or the sun shines.

I'm sure you're being funny, but that's not really true. My tbi'd 2.t is just as reliable and hassle free as my 4.0HO ZJ and my OBDII XJ.

 

Yes. If the first Tips are followed thoroughly with good effort, the problems experienced in the future are no worse with Renix parts than HO parts failure rates.