ratrapp

well if you still have the original cps i would reinstall it and hard wire it.once again if it ran fine before look back at what you replaced or worked on.it possible the o2 sensor could be stuck so if you just unplug it you can eliminate that.also tps could be out of adjustment or just going bad.at least you have it idling now.

this may sound like alot of work but if the front three don't seem to making much difference when you unplug them i would take the fuel rail back off and swap the front three with the back three and see if the front three cylinders start showing a difference.if it does then the injectors are bad,if not then you have other problems.if it ran fine before you done this then i would try this.ive learned over the years that if its not broke then don't fix it lol.

if your holding fuel pressure and the pressure is in spec i think you could rule out the pump.how did you go about cleaning the inectors?i have a friend that actually has an injector flush machine that cleans and flows them.cps are pretty sensitive on the 4.0s.i don't know what brand you used but i do think the oems are discontinued for the renix unless you can find a nos one.

did it run like this originally or did this start when you swapped the injectors?truthfully it may be time to let someone else look at it.there is no shame in it.I'm afraid theres only so much members can tell you to try or check without being there.

is it possible the front three arent plugged up in the right order?or maybe the intake gasket has a vacuum leak around the front cylinders?

the nexen roadian a/t is also a very good tire for the money.

i havent heard of people doing that before but its possible .it could work.you could check into that.i like the smoke machine because it pumps smoke into the system.ive seen people you shop vacs flipped in reverse to check for exhaust leaks using soap and water mixed in a squirt bottle.it may be a little more difficult to find vacuum leaks with this method.

yes thats exactly what I'm talking about.check the manifold for cracks(pretty common for 4.0).if the manifold gasket itself is leaking it can cause it to run rough being the exhaust and intake share the same gasket.i have a smoke machine i bought off of amazon.its the autool brand i think.i wasted money before buying a pos one off of ebay that is made from an old paint sprayer that was a waste of money.the smoke machine is invaluable for finding exhaust and vacuum leaks.

by the video,it sounds like an exhaust leak on the manifold but i could be wrong.it kind of sounded like it was trying to idle alittle better as it was running.i think 30 psi may be on the low end of the scale but i think its acceptable.you could try unhooking the injectors 1 at a time and see if it idles worse or stays the same.if it stays the same at least you know which cylinders are giving you problems.you could unplug the spark plug wires one at a time as well but the injectors won't give you a shock.

my rear prop valve was bad on mine.i never could get a good pedal until i bypassed the valve.i replaced wheel cylinders,master cylinder,hoses and lines until i finally bypassed the valve.

I'm definitly buying some when they come out.its all thats really keeping my from getting my 86 on the road.

you may still have other issues even when you fix this but it needs to be addressed before anymore repairs or attempted starts are made.after you put the regulator on and see that it holds pressure you may want to hold the throttle open some to see if it starts.it may be partially flooded from the leaking regulator.and no,holding the throttle open an an efi vehicle won't flood it.the throttle body is nothing but an air flapper.

my bad,i thought i read you didnt have fuel leaking out of it.damn i shouldnt read without glass's on lol.and no there shouldnt be any fuel in the line ,period.this causes fuel to go straight in the intake every time the key is cycled on.thats probably why the fuel pressure drops so suddenly.

just get a cheap set of copper plugs to get it running.it doesnt need or will benefit from platinum or iridium plugs the stores will try to sell you.try new plugs before you spray carb cleaner in the holes.this is just a test eliminate that you don't have fuel on the plugs to combust.

have you checked under the distrbutor cap to make sure that the rotor button hasnt come off the shaft.ive seen that before as well.

i do stress a very small amount of carb cleaner.I'm talking like the amount that comes out of those battery powered air fresheners.too much will either flood or hydrolock the engine.

thats a good sign.if all the plugs look good and your sure your getting spark then spray a small and i do mean small amount of carb cleaner in each spark plug hole,reinstall the plugs and see if it starts or try to start.

usually if theyre going bad youll see gas coming out of the nipple that the vacuum hose attatchs to.it can also be bad and fuel not coming out of the nipple as well.you would have to remove the regulator and fab up a block off plug to eliminate the regulator and start narrowing down if you have either a stuck injector or a leaking pump.if any plugs are fuel soaked then that may be signs of a stuck injector.

to use the noid light all you have to do is unplug 1 injector and plug the correct noid light into the harness and have someone crank it.it should pulse to let you know the ecm is commanding the injectors to pulse.did you pull all plugs to verify theyre not gas soaked?also you should be able to hold fuel pressure for a while.thats saying if it drops immediatley then you can either have a stuck open injector,bad regulator or there is a leak inside your fuel pump assembly from where the hose connectors to the hanger or ive even seen the pump itself leak where the pump body is assembled.

did you verify injector pulse and you said you have spark,but did you just spark at the wires or did you pull the plugs to see if maybe theyre gas fouled?

there will be one in the kit to check injector pulse.it might not be labeled ev1 but there is one in there.

yes,even the renix 4.0 uses ev1 style injectors that are pretty common.

a noid light will determine if the injectors are getting signal to operate,not the actual function of the injectors.remember an engine needs spark,fuel and compression to run.i doubt it suddenly lost compression but i have seen stranger things but its highly unlikely.trust me if i were closer i would swing by.

i think you really need to take a step back.first where ive read youve never actually checked fuel pressure,just pushed the schraeder valve in and seen some fuel.harbor freight sells cheap enough fuel pressure gauge kits.then if you have proper fuel pressure and flow,check for spark.i persoally wouldnt have worried about modifing the cps sensor until i had it running again.i know you did put a new pump in it but i own a garage and you won't believe the amount of bad new parts i get a week(good american quality lol)you can also buy cheap spark testers from harbor freight.also you havent checked for injector pulse either with a noid light which also can be picked up at harbor frieght pretty cheap.most of these harbor freight tools are decent enough for the diy'er.

i used an uphill mfg rear bumper on mine and it fit great.