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Well, color me baffled. Went out tonight and was ready to be an electrical gremlins sleuth when right off the bat I noticed that one of the air lines to the intake(it's not important. Definitely NOT the largest air inlet besides the throttle body itself. >_> ) was not connected. Once that was connected, oddly enough, the motor fired right up and ran beautifully. Well, its still got a miss on cylinder 2. Pulled the spark plug to see if the injector was firing and other than it being dark, it was covered in fuel. So, I switched it with the plug from 3. No change. Still misfire in 2. Then I swapped plug wires and again, no change. I verified spark between plug and wire as well as wire and cap. It seemed that the spark between if and wire was a little bit more yellow than between the wire and cap. Only things I haven't to rule out are cap and rotor. Those were brand new when I bought the truck and they were kept in the cab nice and dry while it sat. I guess I'm gonna buy another cap and rotor from the dealership tomorrow and see if that clears anything up.
in the meantime, here's the latest video of the motor.
New rotor in hand. cap wont be here until tomorrow which means that ill have to pick it up on Saturday unless i can convince my dad to grab it for me while hes in town. If these dont fix anything, im pulling the VC and checking the valve lash. Even though compression checls good, maybe theyre just a bit too tight on the intake and its impeding things?
I'm with you on checking the valves again. Puzzling that you have good compression, though. If either rocker was tight enough to lift a valve off its seat, the compression wouldn't be there.
Any possible way a vac leak can be affecting only cyl #2?
I'm with you on checking the valves again. Puzzling that you have good compression, though. If either rocker was tight enough to lift a valve off its seat, the compression wouldn't be there.
Any possible way a vac leak can be affecting only cyl #2?
a compression check for slight valve issues won't work well. I had a Honda that idled poorly and stalled with compression numbers around 190. I did a leak down test and had 60 to 70%in all cylinders. The culprit was a previous owner broke a timing belt and it slightly bent the valves. Enough where under load it sealed but at idle it didn't.
i would also check the lash again as your next step. And after that possible swap injectors around and see if the issue follows the swap.
Glad to see progress is good!
FWIW, my aforementioned valve issue was diagnosed by leak down testing bad, so probably not the same issue, but still good to check
Swapped the rotor tonight. Went to fire and no start again. Crank and rumble then dead. Had to have doomy open to AFM again to get it to start. But once she fired and ran, she would fire up again without the AFM pressed. And rotor did nothing. Still a misfire and maybe even made it worse because it seemed like it was idling rougher.
I need to wait until I get the cap before I tear into the valve cover.
any ideas as to why it wouldn't fire? It's really frustrating me. I have a feeling the COR is failing.
im leaning towards COR because until i push the door open manually, i dont hear the click in the passenger footwell. it also wont jumper still. not until it has been running. once running, i can put the jumper in and shut it off and hear the pump working.
still doesnt explain misfire. if the cap doesnt work, then i can rule out spark completely. ive replaced everything else except coil and that is working, so we are good there. next would be to check the valves and if they are all in spec, after that, i dont know. i would say pull the #2 injector and check my wiring there. after that......i guess take it to a shop because i have no idea what else to check.
Checking the valve lash is a fairly painless amd quick thing to do. yea, i just dont want to have to fight the spaghetti monster again. Although......i might be able to run the vacuum lines from memory now, ive done it so much. haha
i don't think your cap is going to fix the issue unless that one is damaged some how I dont think so either, but ive been surprised by things like this in the past with other rigs.
the ignitor works or else you wouldn't be running. yea. that one is easy to rule out. hahaha.
if I'm not mistaken the cor is what gives the fuel pump its power to start up until the vafm circuit takes over, so i would look there first as well. checked with my local dealer. when they had CORs available they were $149. it is a discontinued part now. so, i dont know where to go from there.
you didn't mix up your injector wiring between the number 2 fuel injector and cold start injector by any chance did you? i dont believe so, simply because the CSR pigtail has a wicked curve to it, and the wires are "lived in" in that position. I could be wrong, but i dont think i am.
Originally Posted by Melrose 4r
x2. That's a really good thought.
this is the only thread i am watching daily. We need to see this truck running right soon!
hahaha, thanks melrose. although im using this to document the build mostly, its nice to know that someone is watching.
Some potentially good news. I pulled out the injectors again today. I was doing more research last night and I guess rebuilt I hectors can get gummed up from sitting on a shelf for extended periods of time. So, I took a look at what I had available and decided to redneck engineer an injector tester. Took some spade clips and cut them in half. Then took some scrap wire I had laying around. Combine them and I have a test harness. Then I took the straw off of a can of carb and choke cleaner and wrapped electrical tape around it. Jammed that into the end of the I hectors and I have a dummy pressurized fuel system. Grabbed a simulated cylinder(empty diet coke bottle) and the simulated ECU(doomy) and tested em out. Didn't get a video until the 3rd injector(sorry for my little one talking. She doesn't know how to be quiet. Lmao.), but you should be able to see how the spray pattern changes after the first few sprays. Injectors 1 and 2 were much worse than. 3 and 4. Almost like a garden hose on half power. So, maybe this has been the problem all along? If it is, then I feel like an idiot. Vital22re told me to do this last week, but I was convinced that it was a myth. I mean, it seemed that way because injectors sit on a shelf for possibly years in parts warehouses; which is true, but they have a special lube ran through them before that a rebuolder wouldn't use.
anyways, here's a couple pics and the video. The injectors are currently sitting with the pintles in a cup of marvel mystery oil injector cleaner. Hopefully it'll break up and disintegrate whatever was left in there. They're gonna get reinstalled tomorrow afternoon.
here's the cut down spade clips.
They will only fit this way. If they aren't cut down, the clips are too wide and will touch.
Redneck engineering at its finest. Seriously though, I'm keeping all of this in a box with my wheeling stuff. Might need them one day.
Cup of marvel mystery oil injector cleaner. The blue tag is my reminder which injector was #2 so I can put it back in its place.
As of right now, I'm calling it. Throwing in the towel. There isn't anything else I can do for this motor. Somehow by checking the valves, I've made it so it won't fire or run at all. Cranks and sputters. Won't run at all. Put the injectors in after checking them again(moved 2 back to 1 where it originally came from) and still misfire on 2. And It runs worse. Barely stays running. Pulled the valve cover and checked all the valve clearances. They were all spot on for a cold motor. Doomy thought the dizzy was a tooth off, so she reset it. And while I was there, I made sure the timing was set correctly. Put everything back together and now she won't even fire. I just don't know what else to do. Don't know what else to check. I'm frustrated and I have 8 days left to get this on the road. I'm flat out of options here. So, I have to find a way to get this thing to the shop. And I have to find a way to pay for it.
The misfire on 2 is wierd, since you have spark, and fuel, timing, and valves are good.
One thing that comes to mind is if the number 2 wire shorts to the block before getting to the plug tip. How clean are the plugs on the outside? Incredibly unlikely but a carbon track along the outside of the plug could cause trouble
combined with thinking you have relay/fuel pump issues, it makes me wonder if there's an electrical issue in the mix like a bad computer or something
I re read the last few pages and got a little hung up on your compression numbers.
I'm not worried about the 118s but cylinder 2 and 3 being 131 was interesting to me. Especially considering those are the two you were having issue with.
those higher numbers give me an impression that you may have leakage between cylinders.
I would redo the compression test. Make sure you have the efi pulled and make sure you perform this test at wide open throttle. If you don't hold the throttle open you will get skewed numbers.
if those numbers repeat you need to make a leak down tester. A basic one would be, air compressor, regulator set to 100psi, ball valve.
use your compression tester end and connect your air supply. Set cylinder at tdc, open ball valve. Record reading on air gauge.
if you have it set to 100psi, and the regulator sits at 70,then you have 30% leak down.
if you find a cylinder, or more that leak down you can follow the hiss to determine the cause.
I'm concerned you have cylinders 2 and 3 leaking into each other causing your higher compression readings on those two.
07-26-2017, 11:51 PM
