MTBTyler Posted May 18, 2012 Share Posted May 18, 2012 1987 Inline 6. auto trans I get in. start it. hit the brake. put it in drive. STALL I drive. slow down for the stop sign get under 3ish mph STALL I have to give it a small amout of gas in neutral then shift just to keep it running. Then put it back in neutral to stop. This is killing my trans. Truck runs fine while moving and idles fine in park or neutral. My EGR is stuck closed so I don't belive this could be it. I replaced IAC I ohm'd the CPS I cleaned the TB I have ford 19lb injectors. I have a home made snokel pluging the fuel pressure reg doesnt change anything. any ideas? Link to comment Share on other sites More sharing options...
MTBTyler Posted May 18, 2012 Author Share Posted May 18, 2012 by the way here's the beast 318128_3556567686293_1635775989_2728341_1562343636_n by mtbtyler666, on Flickr Link to comment Share on other sites More sharing options...
HOrnbrod Posted May 18, 2012 Share Posted May 18, 2012 Try adjusting the Throttle Valve cable (commonly called the kickdown cable) at the throttle body. Link to comment Share on other sites More sharing options...
DREDnot Posted May 18, 2012 Share Posted May 18, 2012 How old is the timing chain? I had an 87 YJ 2.5 that did the same thing. Replaced all the obvious stuff. No change. A grizzled old jeep dealer mechanic said to replace the timing set(cam retarded). BOOM ...fixed. My MJ is acting almost the same without the full stall. I am gathering the parts to change mine out soon. Just a thought Link to comment Share on other sites More sharing options...
MTBTyler Posted May 18, 2012 Author Share Posted May 18, 2012 The timing chain has never been replaced that I know of. 130k but id like to try other stuff first before riping into it. How should the kick down be adjusted? I have it so when your at idle it has a little slack. I kow ford the way you do it is to put a pressure guage on the TV port on the trans. Same with jeep? Link to comment Share on other sites More sharing options...
cruiser54 Posted May 19, 2012 Share Posted May 19, 2012 Clean your throttle body and IAC before proceeding any further. Also, do the following: 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 Link to comment Share on other sites More sharing options...
MTBTyler Posted May 19, 2012 Author Share Posted May 19, 2012 Ive cleaned the TB and IAC and replced it and cleaned the hole that it goes into 5 times already. I adjused the kick-down all the way tight and all the way loose. Not much difference. My next step is to clean out that connector then Link to comment Share on other sites More sharing options...
MTBTyler Posted May 21, 2012 Author Share Posted May 21, 2012 cleaned out the connectors. now the truck runs worse.. I'm going to glob some greese on it later and see if that fixes it. Link to comment Share on other sites More sharing options...
MTBTyler Posted May 21, 2012 Author Share Posted May 21, 2012 cleaned the c101 conector and the on to the right of the booster. Now it runs really bad. idles rough then rps will go crazy high every now and then. tps idle volts are around 7.3v Should be higher I know. When the truck idles rough the fuel pressure is at around 38-40 then the pressue will drop to around 30 and the rpms will spike then run good for a few sec until the fuel pressure goes back up. MAP vacc line is good. I hooked the smoke machine up and no major leaks. HELP :???: Link to comment Share on other sites More sharing options...
MTBTyler Posted May 21, 2012 Author Share Posted May 21, 2012 I had the scanner hooked up to it to. The timing is 10* advaced. Then when the engine revs up by its self it jumps to 35* advace :hateputers: Link to comment Share on other sites More sharing options...
MTBTyler Posted May 23, 2012 Author Share Posted May 23, 2012 IAC works I adjusted TP to exactly 0.8v MAP supply volts is normmal 5v. Running it jumped between 1.5 and 2.8 allitle high but I'm guessing this is because the crazy idle. I ohmed the ground wire and it it had 3ohms of resistance.... NOT GOOD? I'm going to try a better meater later today. The truck isnt stalling as much it just idles like crap and not %100 power. Link to comment Share on other sites More sharing options...
skidoo_j Posted May 23, 2012 Share Posted May 23, 2012 IAC worksI adjusted TP to exactly 0.8v MAP supply volts is normmal 5v. Running it jumped between 1.5 and 2.8 allitle high but I'm guessing this is because the crazy idle. I ohmed the ground wire and it it had 3ohms of resistance.... NOT GOOD? I'm going to try a better meater later today. The truck isnt stalling as much it just idles like crap and not %100 power. Re TPS so your reference voltage is 5.33v? it's to be set at 15% of reference Voltage.. I doubt it has anything to do with the crappy idle.... I too am having some idle issues, but almost the reverse of yours. I've replaced every sensor with new, and cleaned every ground. what happens on mine is the idle will not come down unless i strain the motor at a stop. Your gear switch may have issues. (you said you had an auto) there's a switch or sensor that tells it it'sin gear maybe that's why you were having issues. Is your IAC stepper motor known to be good? It's possible it has a dead spot, but that would usually just cause a very high or low idle not erratic or horrible sounding. have you gone back to basics.... Pulled plugs and examined them. checked spark wire resistance. rotor, cap, stator (i think that's what it's called located under the rotor has three wires that go to it.. tells the truck whats firing) , fuel filter, compression. Link to comment Share on other sites More sharing options...
skidoo_j Posted May 23, 2012 Share Posted May 23, 2012 here's a link to a renix fuel system manual. Keep in mind it has some differences with the wiring schemes i've found vs my 89. But tells you how to test most sensors. http://www.pirate4x4.com/tech/billavist ... manual.pdf Link to comment Share on other sites More sharing options...
MTBTyler Posted May 24, 2012 Author Share Posted May 24, 2012 I replaced the IAC. And it runs the same if I unplug it. I replaced the MAP today. No difference. Took the plugs out and the centers were whiteish gray and they were black around the outside. The truck runs rich. You can smell it, it gets 10mpg, scanner says the O2 sensor was lean. Took the cap off. There was white buid-up on the points and the rotor end was a bit dirty. I cleaned it off with sandpaper. NOTHING I just did the fuel filter not too long ago. All my friends have bad compression cherokee's They all blow air out of the oil cap, there oil has gas in it and they are slow. MY truck's oil smells like oil and there isnt any air coming from the oil cap. Ill look up on the trans sensor and stator. Thats my next project :thumbsup: Link to comment Share on other sites More sharing options...
cruiser54 Posted May 24, 2012 Share Posted May 24, 2012 IAC worksI adjusted TP to exactly 0.8v MAP supply volts is normmal 5v. Running it jumped between 1.5 and 2.8 allitle high but I'm guessing this is because the crazy idle. I ohmed the ground wire and it it had 3ohms of resistance.... NOT GOOD? I'm going to try a better meater later today. The truck isnt stalling as much it just idles like crap and not %100 power. Re TPS so your reference voltage is 5.33v? it's to be set at 15% of reference Voltage.. I doubt it has anything to do with the crappy idle.... I too am having some idle issues, but almost the reverse of yours. I've replaced every sensor with new, and cleaned every ground. what happens on mine is the idle will not come down unless i strain the motor at a stop. Your gear switch may have issues. (you said you had an auto) there's a switch or sensor that tells it it'sin gear maybe that's why you were having issues. Is your IAC stepper motor known to be good? It's possible it has a dead spot, but that would usually just cause a very high or low idle not erratic or horrible sounding. have you gone back to basics.... Pulled plugs and examined them. checked spark wire resistance. rotor, cap, stator (i think that's what it's called located under the rotor has three wires that go to it.. tells the truck whats firing) , fuel filter, compression. Skidoo, did you ever check to see if someone "screwed" with the Throttle Body blade adjustment? Link to comment Share on other sites More sharing options...
cruiser54 Posted May 24, 2012 Share Posted May 24, 2012 I replaced the IAC. And it runs the same if I unplug it. I replaced the MAP today. No difference. Took the plugs out and the centers were whiteish gray and they were black around the outside. The truck runs rich. You can smell it, it gets 10mpg, scanner says the O2 sensor was lean. Took the cap off. There was white buid-up on the points and the rotor end was a bit dirty. I cleaned it off with sandpaper. NOTHING I just did the fuel filter not too long ago. All my friends have bad compression cherokee's They all blow air out of the oil cap, there oil has gas in it and they are slow. MY truck's oil smells like oil and there isnt any air coming from the oil cap. Ill look up on the trans sensor and stator. Thats my next project :thumbsup: Scanner should show the O2 sensor switching rapidly from rich to lean constatly. If not, a faulty O2 sensor will stay "lean" and ECU will default to a richer fuel map. If you had things get worse after cleaning/touching the C101 and you've got 3 ohms of resistance in your sensor grounds, the sensors can be fine but the ECU isn't seeing proper values. Does the idle change if you wiggle the harness along the valve cover, between the MAP and C101? Here's a sensor ground test for you: Cruiser’s Renix Sensor Ground Test Set your meter to measure Ohms. Be sure the key is in the OFF position. Using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector of the TPS . The letters are embossed on the connector itself. Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it runs parallel to the valve cover and also near the MAP sensor mounted on the firewall. If you have an 87 or 88 with the C101 connector mounted on the firewall above the brake booster, wiggle it, too. You want to see as close to 0 ohms of resistance as possible. And when wiggling the harnesses/connectors the resistance value should stay low. If there is a variance in the values when wiggling the wires, you have a poor crimp/connection in the wiring harness or a poor ground at the engine dipstick tube stud. On 87 and 88 models, you could have a poor connection at the C101 connector as well. Revised 05/03/2012 Link to comment Share on other sites More sharing options...
cruiser54 Posted May 24, 2012 Share Posted May 24, 2012 Just an FYI regarding sensor testing. I don't think that's your problem at this point but it takes 20 seconds to check. The CPS ohm test is not reliable at all. This is way more definitive: Renix CPS Testing and Adjusting Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark. Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue as the CPS will test good when in fact it is bad. The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark. Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected. You should get a reading of .5 AC volts. If you are down in the .35 AC volts range or lower on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer. Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off. A little trick for increasing the output of your CPS is to drill out it’s mounting holes with the first drill bit that just won’t fit through the original holes. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts. Revised 11-29-2011 Link to comment Share on other sites More sharing options...
skidoo_j Posted May 24, 2012 Share Posted May 24, 2012 I replaced the IAC. And it runs the same if I unplug it. I replaced the MAP today. No difference. Took the plugs out and the centers were whiteish gray and they were black around the outside. The truck runs rich. You can smell it, it gets 10mpg, scanner says the O2 sensor was lean. Took the cap off. There was white buid-up on the points and the rotor end was a bit dirty. I cleaned it off with sandpaper. NOTHING I just did the fuel filter not too long ago. All my friends have bad compression cherokee's They all blow air out of the oil cap, there oil has gas in it and they are slow. MY truck's oil smells like oil and there isnt any air coming from the oil cap. Ill look up on the trans sensor and stator. Thats my next project :thumbsup: Scanner should show the O2 sensor switching rapidly from rich to lean constatly. If not, a faulty O2 sensor will stay "lean" and ECU will default to a richer fuel map. If you had things get worse after cleaning/touching the C101 and you've got 3 ohms of resistance in your sensor grounds, the sensors can be fine but the ECU isn't seeing proper values. Does the idle change if you wiggle the harness along the valve cover, between the MAP and C101? Here's a sensor ground test for you: Cruiser’s Renix Sensor Ground Test Set your meter to measure Ohms. Be sure the key is in the OFF position. Using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector of the TPS . The letters are embossed on the connector itself. Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it runs parallel to the valve cover and also near the MAP sensor mounted on the firewall. If you have an 87 or 88 with the C101 connector mounted on the firewall above the brake booster, wiggle it, too. You want to see as close to 0 ohms of resistance as possible. And when wiggling the harnesses/connectors the resistance value should stay low. If there is a variance in the values when wiggling the wires, you have a poor crimp/connection in the wiring harness or a poor ground at the engine dipstick tube stud. On 87 and 88 models, you could have a poor connection at the C101 connector as well. Revised 05/03/2012 Cruzer What sort of voltages should the sync wire be fluctuating between? I have a new bosch 02 sensor and am also trying to chase down a ghost in my idle. I measure 1.6 ohms across the red/black (heater) when connected. I get 12v across the red/black when key turned to on for a a few seconds. black to ground has .3 ohms... so my wiring to the o2 sensor checks out fine iirc. I back probed the sync wire and at idle I range as low as .65 (instant) and spike at 5.03 and it seems to cycle between 2.3+-.5 to 4.9+-.5v dc with it rarely being lower then 1volt when giving gas arround 2200 rpm it drops then starts to stabilize 2-3.5 volts back and forth. it's definitly cycling, but i though the voltages were to be much lower, i thought i should see .6 and 2.5 as a high. is my O2 sensor incorrect for a renix era? Link to comment Share on other sites More sharing options...
cruiser54 Posted May 24, 2012 Share Posted May 24, 2012 What are you calling the "sync wire"? 3 ohms is alot of resistance in the ground circuit for the sensors BTW. Link to comment Share on other sites More sharing options...
skidoo_j Posted May 25, 2012 Share Posted May 25, 2012 What are you calling the "sync wire"? 3 ohms is alot of resistance in the ground circuit for the sensors BTW. 0.3ohms well there are three wires red, black, grey... black has 0.3 ohms to ground red carries 12v during initial key on grey wire i called sync.... when truck running voltage readings in prev post above. Link to comment Share on other sites More sharing options...
cruiser54 Posted May 25, 2012 Share Posted May 25, 2012 What are you calling the "sync wire"? 3 ohms is alot of resistance in the ground circuit for the sensors BTW. 0.3ohms well there are three wires red, black, grey... black has 0.3 ohms to ground red carries 12v during initial key on grey wire i called sync.... when truck running voltage readings in prev post above. Your oxygen sensor is working fine if you see fluctuatations from 4.9 down to .2 or so, especially if it's rapid. Have you done the sensor ground test yet? Link to comment Share on other sites More sharing options...
MTBTyler Posted May 25, 2012 Author Share Posted May 25, 2012 ok well I hooked the scanner up again and I had 2 ex-master ford tech dudes look at it. They were saying how crazy all the readings were and there was 5V at the O2 sensor. They think that one of the VREF wires for one of the sensors has shorted out and is messing the whole system up. OR the computer is bad. MY idea is to OHM all the out put VREF pins on the computer connector to ground. if there is very low resistance then I found my problem?? Link to comment Share on other sites More sharing options...
cruiser54 Posted May 25, 2012 Share Posted May 25, 2012 What are VREF wires? And why haven't you checked out the sensor ground circuit as suggested? Takes 2 minutes. Ever think that sensor values would be all over the place if they had bad grounds? Link to comment Share on other sites More sharing options...
MTBTyler Posted May 25, 2012 Author Share Posted May 25, 2012 Vehicle referance. AKA supply wires 5 volts. I'm going to check the ground today. Link to comment Share on other sites More sharing options...
MTBTyler Posted May 30, 2012 Author Share Posted May 30, 2012 Friend gave me a computer out of an 89 cherokee. hooked it up to my truck now it runs great! Link to comment Share on other sites More sharing options...
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