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i wouldn't think it would take five seconds for the truck to start when turning the ignition. i was meaning to ask this question a while back but hadn't got around to it. so what is my issue, or is that how it's supposed to be, which i don't assume it should be.

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Gibbs, start with the simple stuff first.

1) Is your battery in good condition?

2) If your battery cables are original, replace them.

3) If and when you buy new cables buy the negative cable from your local parts place that has the main wire running to the block and a second wire from the terminal to the fender.

4) Replace that stinking braided ground cable at the back of the block.

5) Then replace your CPS.

 

If none of this improves your start time then we can start discussing other options.

I know everyone says this is normal on our engines. Mine did the same thing. However by changing these, my 4.0 with 220,000 miles on it now starts as fast as any new car. Of course I also changed a crap load of other stuff but nothing made as much of a differnce as that damn negative cable. And that's also considering my battery is shot.

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if the battery was bad, would you notice low voltage on the gage? i won't be near my truck till tomorrow night, but i know the gage stays around 14volts or half way when the truck is running. it's about a quarter when just turned on.

 

i don't know if the battery cables are original or not, i don't remember what they look like at the moment either.

 

i already need to get some braided wire so i can pick up some extra.

 

 

http://cpwstore.carpartswholesale.com/c ... 67006+7532 ?

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Mine takes 3 seconds most of the time. It is typical of the Renix system to take 3-5 seconds to fire...although 5 seconds is getting a little long.

 

i started questioning it when it took that long and my dad was curious of why it did as well. i've driven cars older than that truck and they started up like a brand new car. so i thought it was odd.

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Mine takes 3 seconds most of the time. It is typical of the Renix system to take 3-5 seconds to fire...although 5 seconds is getting a little long.

 

i started questioning it when it took that long and my dad was curious of why it did as well. i've driven cars older than that truck and they started up like a brand new car. so i thought it was odd.

It is a peculiarity of the Renix system. I don't understand the specifics, but the Renix system doesn't "learn" any settings from driving. Every start is a "clean boot" for the system, and it needs a number of engine revolutions to check and be sure that everything is synchronized before it'll actually fire up. There is no way you will EVER get a Renix system to fire the instant you turn the key. Just accept it -- it ain't gonna happen.

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Mine takes 3 seconds most of the time. It is typical of the Renix system to take 3-5 seconds to fire...although 5 seconds is getting a little long.

 

i started questioning it when it took that long and my dad was curious of why it did as well. i've driven cars older than that truck and they started up like a brand new car. so i thought it was odd.

It is a peculiarity of the Renix system. I don't understand the specifics, but the Renix system doesn't "learn" any settings from driving. Every start is a "clean boot" for the system, and it needs a number of engine revolutions to check and be sure that everything is synchronized before it'll actually fire up. There is no way you will EVER get a Renix system to fire the instant you turn the key. Just accept it -- it ain't gonna happen.

 

well knowing that, i will accept it, no reason to waste money on something that can't be changed.

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Is their any adjustment on the CPS ? I had a new one put on, have new injectors, plugs, wires, cap, completely changed the positive and ground cables with the heavier ones ala 5-90, new tps, fuel pump, fuel pressure regulator, and my 1989 4.0 with 97,000 miles still starts like slow.

 

I also have another 1989 with a 4.0 that I do nothing to but abuse and put gas and oil in and I swear it starts quicker than the one I dump all my money in to.

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Is their any adjustment on the CPS ? I had a new one put on, have new injectors, plugs, wires, cap, completely changed the positive and ground cables with the heavier ones ala 5-90, new tps, fuel pump, fuel pressure regulator, and my 1989 4.0 with 97,000 miles still starts like slow.

 

I also have another 1989 with a 4.0 that I do nothing to but abuse and put gas and oil in and I swear it starts quicker than the one I dump all my money in to.

Nope...no adjustment to the CPS. As Eagle said...there is nothing you can do about it but live with it. Some start a little quicker than others, but they are all slow ;) .

 

Yours is a great example...you have done all that work and it did nothing to help this particular issue :cheers: .

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Well, I didn't do it all to help with the starting issue. I did it cuz the stuff is 19 years old, and I want daJeep to run as good as it can............and it does that. Idles nice, runs beautiful on the road and averages around 18 mpg with oversize tires on it.

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There is one more thing you can do. Jeep had a fix kit for the CPS that contained a new wire harness that went directly to the computer, bypassing the factory harness. Eagle knows more about it than me though.

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There is one more thing you can do. Jeep had a fix kit for the CPS that contained a new wire harness that went directly to the computer, bypassing the factory harness. Eagle knows more about it than me though.

Well, I know the kit exists. I can dredge up the part number, but Brent (BLHTAZ) can probably find it faster. The deal is that (supposedly) the original wiring harness was long enough and the wire small enough that as the circuit degraded with age & time, the CPS signal to the ECU got weaker. So the factory came out with a retrofit harness that's basically two wires, direct from the CPS connector under the hood directly through the firewall and straight into the ECU.

 

Mine are all 87s or 88s that have the C101 connector, so this retrofit kit is highly recommended for them (and has been installed in the two I drive regularly). I don't know if the factory recommends it for the mid-89 and newer Renix models that don't have the C101 connector. Brent?

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I don't know if the factory recommends it for the mid-89 and newer Renix models that don't have the C101 connector. Brent?

The Patch Kit (part #4443965) shows to be used through 1990. There are still plenty available with a retail price at $65 - $70 depending on dealership used. I can get it for anyone that needs it for $46 + shipping of $3 for USPS.

 

I only show one available in my local warehouse, but 269 show to be in the national warehouse in Detroit. :cheers:

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The Renix 4.0 will never start fast due to the diagnostics being done on the first few cranks. I believe the item is to solve issues with no starting at all caused by corrosion at the contact points of the wiring harness.

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ahh, well that's still good to know then.

 

i need another truck for work in the first place, so i plan on financing a new truck several months after i start working anyways. the mj is going to be a project but not a crawler project, i am going to make it as close to brand new (with other options) as i possibly can. and i have a bmw 2002 that is a project as well.

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so this may or may not decrease the amount of time it takes to start the truck.

It probably will not decrease the start time. It usually makes the difference between starting or ... not.

 

You aren't listening. You can NOT decrease the start time with a Renix. Don't waste time and energy trying to "fix" something that's an inherent part of the system.

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