jmderyke

Most usual cause for back fires are air leaks so check everything intake, exhaust, vacuum lines, egr valve. Have a work manual for your truck? If so look at trouble shooting guide and it will lead you to some proper tests. If not......mmmmm you can look up a pdf manual on the internet and download it for free. I downloaded one for my comanche it covers xjs and mjs. It is missing quite a few things but it will help you for sure. I don't have ac on my 2.5 so i don't have that problem. It should be fairly easy to get too, maybe a universal joint on just before the socket or a wobble extension??? Or just put the socket on the plug and put a wrench on the end of the socket? sorry idk

Well today was the first day i got to drive her around (I replaced the control arm bushings) and it is actually a noticable difference! I had a weak spot when taking off in first gear and it completely gone, with slightly better throttle response. I didn't notice any increase or decrease in top end power. Its most noticeable when the throttle plates are barely open, and you can hear the vacuum at different throttle positions or load conditions. Cruising was easier to do for better words it seemed a bit smoother. I haven't noticed anything bad or worse yet, I will run a tank or two threw and calculate my mpg and post that later. All and all not a bad trick. :yes:

mmm i think you should the sensor location near rear of head. the ecu could operate on different resistance readings of the sensor

I could just kick myself :headpop: I went and ordered a entire polyurethane kit from 4WD.com and I got it but I just noticed something. The sleeves that go into the bushings are for standard sized bolts and my original bolts are metric. So I'm swapping out the bolts with Standard to get a tight fit. Most of them its no problem to swap but the on the upper control arm bolt that threads into the frame, its M10x1.5 and i can't drill it out to re-tap to a different size because the tranny is in the way. :wall: so i gotta fabricate a new spacer NO BIG DEAL haha I'm just posting this just in case some is re-doing their bushing on a custom to maybe save them some time. happy jeeping :typing:

o yeah i forgot....2.5 have the worst fan clutches in the world they freeze up and make the fan run all the time. I ripped mine off a while ago and put a electric fan on. I forgot about that trick Eagle nice!

Are these aftermarket gauges or other jeep gauges? If i was in your shoes id keep the sensor thats for the ecu in its location, and just find a new location for the gauge sensor. Jeep usually had two coolant sensors one for the ecu and the other for a gauge. Is one hiding from you maybe? Try the block drain bolt, or some inline 6cyls had a sensor location on the very back of the head, drivers side right near the valve cover for coolant sensor. If one is not there maybe its been closed with a allen bolt. Some jeeps had coolant sensor on the intake manifold (not to be fooled by the MAP sensor). If still no location for sensor id just drill a hole and tap some threads on the thermostat housing and install it there. Maybe pick one up from the junkyard first just incase it won't work of you mess up. good luck

lol funny stuff :fool: anyway my problem may not help you but its a thought look at "fyi control arm knock", this is a problem that i had, and that I'm fixing at the moment. It was a knocking sound in the front that i felt under my feet. I couldnt find what it was for a while i just over looked the upper control arms. I pryed on them and they seemed ok, i didnt see how bad they got until i remove them.

I am also having the same problem here's my findings. (some of these may not be your problem) First run oem thermostat 195 degree. the thermostat on jeeps open slower than other cars because it get bypassed to the heater core and radiator right at thermostat housing, if you have a 180 degree or lower it will open too soon and close early never get to operating temperature. Assuming your 87 is the same as my 86 there are two temperature sensors, one is for the ecu and the other is for gauge. sounds like the one for your gauge is accurate, the other might be on the intake manifold drivers side, on the side of the manifold not on top (one on top is air flow meter) this one controls your ecu. if this is off it will constantly be telling your ecu that engine is very cold resulting in rich air fuel mixture making it hard for engine to reach operating temp. Check your spark plugs for incomplete combustion this will be all black all around electrode and insulator. You want coco brown color. If this is the case your air/ fuel mixture is off or incorrect heat range of the plug. Incorrect heat range happens often due to jackass behind counter giving someone high performance plugs that has lower heat range instead of stock heat range or you live in cold area and may require hotter plug. hope this helps

I found my knock from a while ago and forgot to post my findings here we go.. It was my upper control arm bolts and bushing sleeve. this is the sleeve with out rubber bushing, I'm replacing with polyurethane bushings and new sleeves. notice the knobs in there and here are the bolts these are the better ones i threw out the worse ones. oops i forgot to save them to post. the knobs in the sleeve and bolts worn against each other. The guy i bought this truck from must have just ignored the noise or he was def.

has anyone swapped out 2.5l tbi for a later multi port injection?

I'm looking for a 1986 2.5 Throttle body for throttle body injection I'm having a hard time finding one.

i would check the u joints, all of them even on the front axle. If any of the seals are bad on the non greasable one and havent be change for years they can be dry and would need replacing. Clunck clunck goes the u joint!

oil pressure sensor

no, i only have the coil wire going into the cap and 4 spark plug wires coming out. On mine its handled at the coil and ecu

my jeep uses a crankshaft position sensor located drivers side bell housing. It locates crank position off of the flywheel teeth. its that way for my 86 maybe the same for yours, fyi your truck wouldnt run if this sensor failed

well any head way today?

I will refine this later, yeah jb sucks but beats the hell out of epoxy. the jb weld isnt in the bore of the plate.I have screws on the side holding the fins in too. fuel won't hurt jb weld and it can handle temps up to 400. and yes the fins are clear of the butterfly.

I wrote how to a few post back how to test the Exhaust Gas Recirculation valve but here's a video on testing it off of you tube to give you a hand. If you don't have a mityvac use a piece of vacuum tube and your mouth http://www.youtube.com/watch?v=IIUFw2KR6rU It might not be the egr valve but its has some of the signs, most likely your problem is in the items you just replaced or had worked on. But this is a very easy test worth a look at.

mmm I'm not sure...........did you get to check the egv and timing yet?

hopefully its the o2 yeah try that test. you test the egr by applying vacuum to the top (see where that vacuum line connects at the top) use a mity vac if you have one if not use a piece of vac hose and suck on it if it holds its good, if air just passes through it, then the diaphram in it is bad. to check the timing get a timing light and connect it to the plug wire leading to the number one cylinder and battery, direct the light to bottom engine pulley timing should be around 10-12 degrees before tdc look at your manual for more info. it will have it under maintenance. even though the timing cannot be adjusted electronically it can be off mechanically.

your o2 sensor is a heated type so those wires getting high ground numbers are the heating coils, and the third is the actual sensor its self i believe its the white one(not 100%) that one should be with in spec so if not change it (but I'm not sure if a bad o2 sensor would make it run this badly) vacuum leaks will make it run this bad (i know you checked), check your emissions equipment, like the egr valve they go bad quite often. did you ensure timing was correct since a fresh rebuild? I will check in later I'm curious good luck

i used 5/8" aluminum ( i had enough space for 3/4" but didnt have any laying around) and 1/16" aluminum sheet for fins (not sure if they are going to help). I made a template of the throttle body holes with gasket material and then I just used my drill and dremel with a hole cutter attachment on the drill and saws all. The hardest thing is making sure everything is center. then sorry to say i used jb weld to make sure the fins had a good seal on them. Now I'm matching the tbi, spacer and intake together for good flow. One thing i may change next time if this works is to use Teflon it insulates and has a melting point of 500 degrees and very easy to work with. Ive seen someone use a plastic cutting board for spacer i don't think its a good choice because polyurethane has a melting point of 260 degrees. :thumbsup:

No one made a throttle body spacer for my 86 2.5 so i made my own for free, from scraps. If it doesnt help atomize the fuel then i will rip it out and it will only would have cost me time ( i have a lot of it ) I will let you know in a week or so if it helped low end power or not. :fool:

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its pretty cheap, but it is the v6........ would rather have l6, stick to your guns he will most likely fold