p51speed Posted August 7, 2012 Share Posted August 7, 2012 ok so as i posted in my intro , im am not a mechanic but , I will work on my truck if i am giving a direction to go so here is my problem. the truck is a 1987 v6 4x4 the truck Idles at about 1700 rpms and after about 30 seconds it will dip down to about 1500 and then a half a second later go right back up . now I did pull the MAF and cleaned it making sure not to touch or damage the wires and I reinstalled it .. did nothing problem still there. then I replaced every vacuum line , problem still there. checked the ecu code. it gave me code 12 the MAF i rest the computer and started the truck. now it idles at 2000 rpm . and the computer is now telling me the coolant temp sensor code 13. I also did some diggin around on line and someone said it might be the idle control valve. problem is I can't find it to replace it . Im at a loss please someone tell me what the hell im doing wrong , I really like this truck but i have no idea where to start. Link to comment Share on other sites More sharing options...
Slartibartfast Posted August 7, 2012 Share Posted August 7, 2012 First thing you need: http://www.nicoclub.com/FSM/pathfinder/1995_Pathfinder/ Download it and save it if you haven't yet, it helps figure out where all the bits are and how to test them. Keep in mind though that it's written for a 95, and your 87 will differ in some ways. Off the top of my head... different t-belt change interval, different intake and injector configuration, different dashboard. It's a good place to start though. Does sound like an idle air control issue to me. Then again the coolant temp sensor can cause all kinds of idle issues. I usually hear about it more with stalling out, though. I'd check the wiring (and check the plug for corrosion) before replacing the sensor. Somebody with a TBI truck can probably be a lot more help than I can. Link to comment Share on other sites More sharing options...
p51speed Posted August 8, 2012 Author Share Posted August 8, 2012 ok here is an update, so I pulled both the idle solenoid and the coolent temp solenoid and cleaned the crap out of them , no instead of surging the engine just idles at about 1820 rpms. so any ideas on how to bring the idle down?. could it be as simple as a timing issue? Link to comment Share on other sites More sharing options...
Mountainbred Posted August 8, 2012 Share Posted August 8, 2012 Hey bud, I have an 87 as well and have gone through your problem with my own. To adjust idle the easy way you can rotate your distributor cap while the engine is running and have someone tell you when the rpm gets to around 900. Make sure that the engine is hot as it will run at a higher rpm while warming up. Also if you notice that the rpm does not drop when the engine is warm you might check your intake coolant plunger (can't remember the actual name of this thing). Its a little cylindrical canister on the front of your throttlebody. There should be a few cooling lines running to it. If the thermostatic plunger in the canister is not moving then the idle will not go down. Its not a cheap fix but It might be worth it, also it is a pain to adjust. It is not controled by electricity so you will not see any plugs going to it, just those two small coolant lines. Hope this helps. 1 Link to comment Share on other sites More sharing options...
mluczaj22 Posted August 8, 2012 Share Posted August 8, 2012 (edited) real easy to adjust. just follow the steps in fsm. Edited August 8, 2012 by mluczaj22 Link to comment Share on other sites More sharing options...
p51speed Posted August 8, 2012 Author Share Posted August 8, 2012 ok so I did do the timing and I got it down to about 900 rpm in (D) but I noticed that the engine ran hot as hell. also pulled the plunger you are talking about and I found out that the plunger thing was stuck inside it . so I pulled it out , now it moves in and pushes out as if a spring were behind it. not sure if I broke it or fixed it? any ideas on that . also I know that the timing says 12 BTDC but I have a nother problem . there are no numbers on my pully just 7 lines and there are no numbers on the indicator as well it looks like this \/ ( indicator) I I I I I I I (pulley) so now im at a loss where I timed it to and if I did it correctly . thanks for everyones help so far. I would like to be acble to come out on top with this deal as I have only spent about 25 bucks on the equipment to tattoo this guy that gave me the truck in trade. 1 Link to comment Share on other sites More sharing options...
mluczaj22 Posted August 8, 2012 Share Posted August 8, 2012 plunger? you mean the high idle adjuster? there should be a couple marks on there that you line up when cold and hot. but that shouldnt push in and out freely. idle in drive should be about 750. first line on the left of the pulley is o dergrees. then 5 then 10 and so on. make sure its warm no accessorys on in drive and adjust idle. the adjust timing. put it at 15 degrees btdc. Link to comment Share on other sites More sharing options...
ahardb0dy Posted August 8, 2012 Share Posted August 8, 2012 I think Mountainbred is referring to the thermo element, it is a wax element that raises the idle until hot coolant rus thru it causing it to drop, if it is not working right it may cause the idle to remain high instead of dropping down as the engine warms up. If you have to adjust the timing or mess with the idle screw than something is wrong somewhere else. Have you tried cleaning the butterfly in the throttle body? I have a FSM for a 87 hardbody (paper copy) will be the same for your truck, can scan pages if you need it. Link to comment Share on other sites More sharing options...
krmiller07 Posted August 8, 2012 Share Posted August 8, 2012 Having an 89 with TBI and experiencing all of these issues in the past, I would first of all recommend bleeding the air out of the cooling system by letting it idle and turning the temp control all the way over to the hottest setting while turning the fan on '4'. Watch the temp gauge and see if it doesn't start to drop. I should mention, that while doing this you'll want to remove the radiator cap to keep an eye on the water level, and fill with 50/50 water antifreeze if low, topping it off when done. Your static timing should not cause erratic idle or overheating, especially if the truck is stationary. Once it's set, (and I advance it a couple of degrees for a little better hi-way mileage and power) it should never change. If the idle is still on the high side after cleaning the Idle Air Control Valve (IAVC) the thing with the plunger! If the rubber tip is sharp on the tip and doesn't have a round groove near the end, it's in good shape. There's an informative thread on this site covering the components of the TBI system. Now after you've done all of this, start and run the engine until it's up to operating tetemperature with all of the accessories turned off, headlights etc. Adjust the idle speed to where you want it. (I personally like it set at about 900 rpm) Turn the fan on, A/C and you should see the idle speed increase a couple hundred rpm's. If it doesn't increase, there's a slotted screw head on the end of the IAVC solonoid that allows you to adjust the 'fast idle' speed,turning it 'out' or counter clockwise, should increase the engine idle speed under load. Sometimes it requires you to turn it 'out' or 'in' a few more turns to see a change in idle speed. Once it's adjusted to where you want it with the blower fan, lights and A/C running, fine tune the the static or regular idle to achieve the desired idle speed. Hope this helps! 1 Link to comment Share on other sites More sharing options...
p51speed Posted August 8, 2012 Author Share Posted August 8, 2012 (edited) ok this is the part that I was talking about . I dont know what it is called. but I took a picture of it for you . as you can see this has two nipples for coolant lines and than a metal plunger, that plunger is what i was taling about, that was sticking and now moves in and out, also can someone please tell me what this part is called ? Edited August 8, 2012 by p51speed Link to comment Share on other sites More sharing options...
p51speed Posted August 8, 2012 Author Share Posted August 8, 2012 I think Mountainbred is referring to the thermo element, it is a wax element that raises the idle until hot coolant rus thru it causing it to drop, if it is not working right it may cause the idle to remain high instead of dropping down as the engine warms up. If you have to adjust the timing or mess with the idle screw than something is wrong somewhere else. Have you tried cleaning the butterfly in the throttle body? I have a FSM for a 87 hardbody (paper copy) will be the same for your truck, can scan pages if you need it. that would be great if you could scan the part about installing the new wax kit. as im kinda at a loss on how to do it . thanks Link to comment Share on other sites More sharing options...
krmiller07 Posted August 9, 2012 Share Posted August 9, 2012 Where was this located on the truck, on the throttle body or somewhere else. I don't recall seeing one of these. Maybe you could take a shot of where it's located too. Link to comment Share on other sites More sharing options...
ahardb0dy Posted August 9, 2012 Share Posted August 9, 2012 (edited) That is the thermo element I mentioned earlier, it has 2 coolant nipples on it, one in, one out. There is a procedure in the FSM for measuring the stroke of the rod to see if it is working. It should be on the drivers side of the TB, the rod pushes against one of the cams that opens/closes the butterfly. It is designed to raise the idle when cold and as the coolant flowing into it gets hot it reduces the idle. Per the bleeding air out of the cooling system, don't the TBI trucks have the air relaease screw in the upper radiator hose? Plastic screw, be careful when removing it. I'll scan the section on testing the thermo element for you first, I don't think it really says how to replace it, it just shows a diagram of the wax element removed. I replaced it when I had my 87 hardbody, don't recall it being that difficult. I believe there is a metal ring like a "C" shape with 2 screws, you remove the 2 screws and the retainer ring and the wax element pulls out. Give me a few minutes and I'll do the scan for you. Edited August 9, 2012 by ahardb0dy 1 Link to comment Share on other sites More sharing options...
p51speed Posted August 9, 2012 Author Share Posted August 9, 2012 (edited) I bout a new wax unit today im just trying to figure out how to install it without meesing anything up yeah mine must have been the original because it took a hacksaw a drill and about 3 hours to get the old one out Edited August 9, 2012 by p51speed Link to comment Share on other sites More sharing options...
mluczaj22 Posted August 9, 2012 Share Posted August 9, 2012 That is the thermo element I mentioned earlier, it has 2 coolant nipples on it, one in, one out. There is a procedure in the FSM for measuring the stroke of the rod to see if it is working. It should be on the drivers side of the TB, the rod pushes against one of the cams that opens/closes the butterfly. It is designed to raise the idle when cold and as the coolant flowing into it gets hot it reduces the idle. Per the bleeding air out of the cooling system, don't the TBI trucks have the air relaease screw in the upper radiator hose? Plastic screw, be careful when removing it. I'll scan the section on testing the thermo element for you first, I don't think it really says how to replace it, it just shows a diagram of the wax element removed. I replaced it when I had my 87 hardbody, don't recall it being that difficult. I believe there is a metal ring like a "C" shape with 2 screws, you remove the 2 screws and the retainer ring and the wax element pulls out. Give me a few minutes and I'll do the scan for you. yes they do. but i dont think your suppose to open it when hot. i personally never had to use it to bleed air. but i do know when you do get air in the colling system the idle will hunt up and down alot until that air bubble is gone. but yes he needs to replace the wax element then adjust it for fast idle and base idles. Link to comment Share on other sites More sharing options...
mluczaj22 Posted August 9, 2012 Share Posted August 9, 2012 I bout a new wax unit today im just trying to figure out how to install it without meesing anything up just a couple screws. put a pin or a pick through the hole on the linkage to hold the throttle back to get it on easier. that spring is REAL STIFF! dont lose the black plastic spacers! Link to comment Share on other sites More sharing options...
p51speed Posted August 9, 2012 Author Share Posted August 9, 2012 I have to wait untill tommarrow to do it . because I accidently put a small hole in in the back of the housing by trying to get the old wax unit out. but im jb welding it now so i will see in the morning what happens Link to comment Share on other sites More sharing options...
mluczaj22 Posted August 9, 2012 Share Posted August 9, 2012 10-4 Link to comment Share on other sites More sharing options...
ahardb0dy Posted August 9, 2012 Share Posted August 9, 2012 Ok, sorry the technical name for that part, straight out of the 89 FSM is "Wax Type Fast Idle Cam", Here is a link to a 1989 FSM for the hardbody, this will be better than me scanning mine as there will be no grease on the pages like mine has, LOL http://www.nicoclub.com/FSM/hardbody/d21_truck_1989.pdf takes a little bit to open, when it's done save it so you have it, the mechanical stuff is mostly the same as the pathfinder I'll post what page you need to look at, starting with page: 221 shows the components on the TB 259 diagnostic table 420 checking idle speed and ignition timing 427 TB diagram showing thermo element (wax type fast idle cam) 428 FAST IDLE INSPECTION AND ADJUSTMENT (see this !!) that's about it, go thru page 259 and it will tell you what page to go to, to do a diagnostic on the specific part, anything else let me know. good luck 1 Link to comment Share on other sites More sharing options...
mluczaj22 Posted August 9, 2012 Share Posted August 9, 2012 there ya go. Link to comment Share on other sites More sharing options...
p51speed Posted August 9, 2012 Author Share Posted August 9, 2012 thanks guys im waiting for it to load now Link to comment Share on other sites More sharing options...
p51speed Posted August 9, 2012 Author Share Posted August 9, 2012 ok so good news thanks to all who replied and help with the problem , the wax was the issue. how ever, since it took everything but anact of god to get the old one out the unit started leaking coolant from around the top of the wax unit. so i jb welded that as well and now i have to wait untill tommarow for that to dry . BUT on a good note before i discovered that it was leaking , it idled at 1100 rpms. warmed up dropped to about 750 rpms. retimed the truck to 13 BTDC and so now its a waiting game to figure out if it will work. , thanks again guys I will keep you posted Link to comment Share on other sites More sharing options...
ahardb0dy Posted August 9, 2012 Share Posted August 9, 2012 good deal, and you got 3/4 of the right FSM too !! Link to comment Share on other sites More sharing options...
krmiller07 Posted August 9, 2012 Share Posted August 9, 2012 I wanna know where you got the 'wax' insert for the defective valve that started this whole project !? Glad you got it fixed...hopefully Link to comment Share on other sites More sharing options...
ahardb0dy Posted August 9, 2012 Share Posted August 9, 2012 wax element = dealer Link to comment Share on other sites More sharing options...
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