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Discussion Starter · #1 ·
Okay so im kinda stumped on a problem i was having. The motor is brand new fresh rebuild bored .020 over with flat top pistons stock cam the rest is just about stock. But i did intial cam break in and ive been driving it a few days now only about 75 miles put on this engine absolutely zero problems with it until now oil pressure has been good temp has been good. But let me get to the point but last night i was out on some backroads and i was climbing a hill (its a 5 speed manual 4x4) and i downshifted into the proper gear to be able to climb the hill it was quite a steep hill and theres many many steep hills on this road and after going up about 10 hills one of the hills were extremely steep so i have it in 2nd gear at about 2k rpm and all of a sudden it started jerking like it wanted to stall out so i tried gassing it a bit more just a little and it started jerking really bad to the point it would almost stall it out so i pulled over and checked everything. Oil, coolant, plug wires, nothing was loose or dangling down so i drove it again and when ever you give it gas it jerks really hard you have to almost give it no gas otherwise it jerks back and forth insanely hard the higher the gear and the more throttle applied the harder it is. It got to the point i had to limp it home in 2nd gear at 2,000rpm at 25mph about 10 miles home and i got home checked plugs and all were good and did a compression test and I was reading 150psi after about 3 seconds of cranking. I tried new wires,cap and rotor since those parts wernt replaced and checked ignition timing with a light and that checks out but now it sounds like its missing and possibly knocking out of the blue hearing a tapping sound gets worse when you rev it up. The truck does still have obd 1 and its tbi and i checked live data and my scan tool in live data is reading that it is knocking but at idle it kinda says knocking yes then no then yes but if you rev it and hold it the data saying knocking yes the whole time. I can't tell if this ticking/tapping sound is internal or external like ive said this is a fresh rebuild i had absolutely zero problems with it until i climbed those steep hills ive been babying the engine keeping it below 3,000 rpm and below 55mph. But i have 3 codes one is for the electronic ignition timing which i had unplugged to time distributor, and code 45 oxygen sensor closed/open loop rich code but CEL is off no check engine light so im quite stumped i dont know how or why it started misfiring or knocking oil pressure has been good and within spec for sure it hasnt over heated, hasn't been beaten on its been babyed. So any help of any kind would be greatly appreciated just shoot your ideas or guesses. Ill be having some friends over to help look into it. I will check to make sure it isn't my transmission but the live data on the scan tool was reading a knock. I havent drove the truck since ive gotten home only had it in neutral so im running out of ideas just about everything engine wise is brand new. Egr valve is new, new gaskets etc only sensors i havent replaced was the map sensor, egr solenoid and some 6 male pin connector next to the egr solenoid so im not exactly sure whats going on or why its knocking or missing please send me your ideas or guesses any questions let me know and ill answer them to the best of my ability THANKS!
 

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Discussion Starter · #3 ·
The knock sensor is brand new as i replaced most of my sensors the knock sensor is located on the passnager side of the engine towards the bottom near the starter motor. And this truck doesnt have a cat on it its just true dual pipes with no mufflers no cats as this was the best exhaust i could get so i could initially start engine and i got it for super cheap and its not even rusty. Pretty sure the only o2 sensor on the truck is the o2 sensor on the drivers side manifold i see no other o2 plug ins on it unless im missing something but i dont know why it wouldnt have thrown a code or acted up sooner. Its just a massive coincidence that this all happened after climbing a steep hill
 

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I can only base this on my own experience. If we have a cat issue which in your case is no cat - and according to what I looked up this truck originally had one, then the information feed from the o2 sensor is going to be a problem. The other question after reading your first post again, is it a hard mechanical knock or is it a pre-ignition/lean knock? I ask because they are easy to get mixed up on. If it's a hard mechanical knock then I would do two things. First a mechanics stethoscope or a piece of rubber tubing to see if you can isolate which side of the engine it is coming from. Hopefully that narrows it down, then second I would pull one plug wire at a time to see if you can isolate it to a single cylinder. Let us know what you find. And the above advice ^^^^ about checking the valve train is certainly valid.
 

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Discussion Starter · #7 ·
I can only base this on my own experience. If we have a cat issue which in your case is no cat - and according to what I looked up this truck originally had one, then the information feed from the o2 sensor is going to be a problem. The other question after reading your first post again, is it a hard mechanical knock or is it a pre-ignition/lean knock? I ask because they are easy to get mixed up on. If it's a hard mechanical knock then I would do two things. First a mechanics stethoscope or a piece of rubber tubing to see if you can isolate which side of the engine it is coming from. Hopefully that narrows it down, then second I would pull one plug wire at a time to see if you can isolate it to a single cylinder. Let us know what you find. And the above advice ^^^^ about checking the valve train is certainly valid.
I cant say for certain if its hard knock or pre ignition knock but ill try and look into it further and for not having a cat technically im ok since theres no post o2 sensors on this truck only one pre o2 on the exhaust manifold no where near were a cat would be. I can look into valve train but i actually did have them off not too long ago and i checked all the rockers to make sure they were good and they are good. But yeah im not sure if with obd1 if a misfire or pre ignition or actual hard knock would set the live data as a knock. But its so hard to determine a problem since ive rebuilt half of this truck new gas tank, fuel pump, fuel filter, rear axles, brakes front and rear, new clutch,new master cylinder and line and slave cylinder, new fluid in everything that holds fluid has new fluid. But yeah ill look into everything i can but its such a challenge as ALOT of things are brand new on this truck.
 

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Discussion Starter · #8 ·
Also would any one have any ideas on why this all wouldve started while going up hill? Like i said this truck ran absolutely perfectly until i was climbing that hill and something mustve happened and boom i had to limp it home since it would jerk back and forth like crazy didnt matter the gear you were in it all mattered how much throttle you would give it. As soon as you pushed down at all on the throttle the truck would jerk like crazy back and forth to the point the truck would almost stall its self and quit. There was a tiny sweet spot in the throttle and that was pretty much absolutely no force on the pedal and that was enough to limp it 10 miles home... so i dont have a clue how or why this all started.
 

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Discussion Starter · #10 ·
Is it the engine that jerks or the whole truck?

Bogie
It started when i was climbing a hill yes it was very jerky if youve ever drove stick and you let a new manual driver try and drive it and hes gets the clutch and gas wrong when you first take off that kind of jerking but juust as bad if not a bit worse. it was in gear and i was already moving ANY throttle would cause it to jerk like a b**tch. But im at home now and its in my driveway in neutral and its not jerking i havent drove it since i limped it home. Now its making a tapping/ticking sound that when you rev it it seems like it gets louder. If you come to the drivers side door it sounds really f*cking loud but i didnt really look into it since i noticed it when i was about to shut the truck off but ill definitely look into it later today. It doesnt jerk when its parked in netural. Could be transmission but i noticed this tapping/ticking sound right after i changed the cap, rotor and wires so it could be a bad part there or manufacturer defect but i have no clue. The sound is hard to explain but ill look into a transmission or transfer case problem. All guages are reading good. Ive been running 88 octane in this truck since ive rebuilt engine so if it was spark knock id think the engine wouldve started doing it when I first fired it up like i said this whole thing started right after i was climbing multiple steep hills which would put a heavy load on this engine and im pretty sure the rings havent seated yet but i was babying it up those steep hills. Also i dont know how i couldve spun a bearing for example or caused any sort of mechanical damage since my guages have been reading oil pressure the entire time and the oil pressure has been responsive meaning if you rev it up the oil pressure increases and it moves so im at a large head scratcher right now. All clearances were checked and everything was lubed up and double checked when i was assembling the engine every bolt going into the engine was torqued to manufacturer spec engine has only 75 miles on it since i rebuilt it and mabye 5 hours or so including idle time and initial cam break in. Im still running the break in oil as i was told to that oil for 250 miles then change oil and filter. Also im running 10w-30 conventional oil with hi zinc break in additive.
 

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Discussion Starter · #11 ·
also my timing is at 4 degrees btc with the electrical advance unplugged i can probably put it to zero btc but im concerned about this tapping sound and i dont wanna cause any mechanical damage to the engine or lock it up but i dont see how that could happen if im getting good oil pressure but who knows. This whole thing is a massive head scratcher and everyone ive had look at it has been stumped so far. Everything engine wise is brand new. Only things that i guess you could say were "reused" were the rods, crank and the heads and block obviously but they were all machined at the machine shop and resurfaced etc.
 

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Because you have a problem that occurred after you drove up a hill certainly doesn't mean one has anything to do with the other . Thinking they are related makes it more difficult to find the root problem . run the usual diagnostic tests , compression , leakdown , fuel pressure , visual inspection of plugs , ohm the wires , try to isolate the noise ,etc.
 

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Discussion Starter · #13 ·
Also i have my scan tool hooked up to the obd1 port and looking at live data and the ecm is reading that it is knocking whether its spark knock or hard knock i dont know yet. Im not sure if obd1 will trip a code for a misfire or knock as i dont see any codes relating to a knock or misfire. But live data is saying that it is knocking on the scanner it reads "knock....... YES" there is no knock retard degrees data
 

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Discussion Starter · #14 ·
Because you have a problem that occurred after you drove up a hill certainly doesn't mean one has anything to do with the other . Thinking they are related makes it more difficult to find the root problem . run the usual diagnostic tests , compression , leakdown , fuel pressure , visual inspection of plugs , ohm the wires , try to isolate the noise ,etc.
Thats what i was thinking as well as soon as i got home i pulled the plugs on 2 cylinders cylinder 1 and 2 and they came out looking good no fouled plugs nothing indicating its running lean or rich. I dropped on my compression tester on those two cylinders and it read 150psi with only it cranking for 3 seconds i probably couldve cranked it longer to see a higher reading but I didn't at the time. I could pull all 8 plugs and check all 8 cylinders for compression and let yall know. But just off the two cylinders i tested it all looked good. Also i have no way to test fuel pressure as i didnt see a Schrader valve on the fuel lines. Also i do not have access to a leak down tester. The plug wires are brand new as of yesterday along with most of my ignition system so i dont see the problem coming from that area but ill double check to be safe. And a fyi the gas tank and fuel pump were placed when i initially was working on this truck as it was a project truck so i did everything i could so i didnt have to redo anything i couldve done when i had it all apart. Also i didnt wanna deal with anything on the truck after i did all the work on it i just wanted to drive it for at least a few years or a year without any problems. this truck has such a little amount of rust for a Minnesota truck. Only rust on the truck is on the inner parts of the frame rail on certain spots too.
 

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At this point there's been a lot of sharing of ideas and thoughts about what it could be but none of us are there and we can't fix it for you. As mentioned before, you'll have to at some point start going through it running the tests that you can run. Members on here will certainly respond and provide information and maybe even an answer. But writing posts that just keep reciting what you had already told us about doesn't add any knowledge or ideas for the members here to work with. As your post above for an example - you ran compression on 2 cylinders but say you can do all 8 of them. You need to check all 8 of them because 2 of them being good isn't fixing anything.

We'll be waiting to hear what your testing shows.
 

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Discussion Starter · #16 ·
Right
At this point there's been a lot of sharing of ideas and thoughts about what it could be but none of us are there and we can't fix it for you. As mentioned before, you'll have to at some point start going through it running the tests that you can run. Members on here will certainly respond and provide information and maybe even an answer. But writing posts that just keep reciting what you had already told us about doesn't add any knowledge or ideas for the members here to work with. As your post above for an example - you ran compression on 2 cylinders but say you can do all 8 of them. You need to check all 8 of them because 2 of them being good isn't fixing anything.

We'll be waiting to hear what your testing shows.
Right. My bad. Yeah ill be diving into it pretty deep later today. As soon as i get done running tests and trying to isolate the problem then ill be back on here to let you guys know.
 

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Discussion Starter · #18 ·
Okay so i did a compression test and a spark plug visual inspection. This is a brand new engine btw. Cyl 1-150psi, Cyl 3-150psi, cyl 5 150psi, cyl 7- 160 psi, cyl 2-170 psi, cyl 4-163psi, cyl 6- 163 psi, cyl 8- 160 psi.
Im not sure why theres such a large variation in the compression numbers. Could always be something on my end i messed up. Only strange things were cyl 3 and cyl 5 had spark plugs that were still white... the tinest hint of brown on them but cyl 2 plug was a dirty white/dirty white and black color? Hard to explain it but the other 2 are still damn near white. Cylinders 1 and 7 are half black half brown so they are probably running rich? Cylinder 4 plug is half white half Brown and half black. Cylinder 6 and 8 are black but dont have foulded deposits on them yet.
 

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Discussion Starter · #19 ·
Okay so i did a compression test and a spark plug visual inspection. This is a brand new engine btw. Cyl 1-150psi, Cyl 3-150psi, cyl 5 150psi, cyl 7- 160 psi, cyl 2-170 psi, cyl 4-163psi, cyl 6- 163 psi, cyl 8- 160 psi.
Im not sure why theres such a large variation in the compression numbers. Could always be something on my end i messed up. Only strange things were cyl 3 and cyl 5 had spark plugs that were still white... the tinest hint of brown on them but cyl 2 plug was a dirty white/dirty white and black color? Hard to explain it but the other 2 are still damn near white. Cylinders 1 and 7 are half black half brown so they are probably running rich? Cylinder 4 plug is half white half Brown and half black. Cylinder 6 and 8 are black but dont have foulded deposits on them yet.
Also i did do this test with all plugs out of it and one cylinder at a time so i did remove all 8 plugs then did it cylinder by cylinder from drivers side then passnager side so odd bank then even bank
 

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Discussion Starter · #20 ·
Heres another update so i hooked everything back up and replaced my coil (had a masterpro) i have a electrical arcing sound that would cause the rpms to jump up and down key on engine off it would only make the sound when i cranked it for 2 seconds with injectors unplugged and coil to distributor unpluged and i isolated it to the coil i bought a new standard ignition one and i did the same test and it no more arcing sound so i fired it up and it was idling higher then normal 1400? For some reason i pulled out the scan tool and i got a new code a code 33 map sensor circuit high so i might have a junked map sensor which i have not replaced but on the data as i was idling the knock on the data was reading no and i revved it to 2 grand and held it there and as i was revving it, it jumped to knock yes then it went to knock no and stayed there with a knock no while i was holding throttle. And i let it idle and i read through all data and nothing seemed out of the ordinary but i still have a tappingish sound? Sounds more like air getting pulsed out of something if you get under its louder looking at my exhuast at the moment as i did see it kind of rattling so it could be my exhuast raddleing against something..? Ill be looking even closer when my mechanic family member comes over so at least ive gotten a few things figured out and possibly fixed? Ill let yall know when i can figure it out but if you guys have any ideas on like a air pulsing sound???? Very hard to explain the sound but i do really appreciate the help. I shouldve taken a few steps back and done diagnostics right away but i didn't and now i know for the future but as soon as i figure more out then ill let you guys know thanks for all your help!
 
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