Ticky and Hard Starting

[ocbinva]

Ok I got a Comanche in trade that had a multitude of issues but one by one they are going away. So far I have replaced the TPS (Made a MAJOR difference!!!), Distributor, plugs/wires/ vacuum lines (This corrected my idle), ball joints, hub bearings, all new brakes and alternator last night. Now I have a issue of a ticky engine, same sound as fuel starving and a little gutless. Stronger when warm and under load. I think it is a timing advance issue but what sensor would that be? CPS?, Knock Sensor?. Also even if I let fuel lines pressurize it still takes 4 or 5 second crank for the engine to start. I wonder if they are linked issues?? The truck runs great except for these two issues. When I get this fixed it is new hoses all around! BTW...I am at sea level. Thanks Rick

[cruiser54]

Year, engine size, trans?

[ocbinva]

Wow...Cannot belive I did not add it. Its an 1987, 4X4, 4.0L, Auto

[Comanche County]

Renix 4.0s do seem to take a slightly longer starter spin before they fire up as compare to a 4.0 HO. 4-5 seconds is kinda long though.

 

My 89' however fires right up when I turn the key after one or two spins. Its all stock.

[cruiser54]

Since it's an 87, expect longer crank times. But, the C101 connector has the CPS wiring running through it and that can reduce the signal the eCU sees, resulting in longer crank times. You should do this regardless as almost all sensor signals run through that crappy connector.

 

Renix Jeep C101 Connector Refreshing

 

 

The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before.

 

Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101.

 

The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time.

Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth.

 

If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together.

 

 

 

Revised 11-29-2011

[cruiser54]

Since it's an 87, expect longer crank times. But, the C101 connector has the CPS wiring running through it and that can reduce the signal the eCU sees, resulting in longer crank times. You should do this regardless as almost all sensor signals run through that crappy connector.

 

BTW, did you adjust your new TPS?

 

Renix Jeep C101 Connector Refreshing

 

 

The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before.

 

Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101.

 

The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time.

Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth.

 

If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together.

 

 

 

Revised 11-29-2011

[ocbinva]

Wow...Thanks!!! I have a new project for this weekend. My goal for this truck is reliability then I can work on body and lift. My hoses are toast so that was the plan this weekend plus the valve cover gasket is shot. No I did not adjust the TPS. I just installed it because it met the advertised tolerances I seen on here. The old one was reading 2.2 open or closed. I had no power and it would not downshift when passing but after that simple fix it ran like a new truck. Should I have made adjustments? I am new to jeeps but not new to a wrench so any insight is greatly appreciated.