Horrible P1259

F23accordowner

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Ok hello all, im new to the site!

I have code p1259, i know what the code says(vtec system malfuntion). I recently have had the cars motor rebuilt at 190k miles. Practically new everything has gone under the hood. New oil pump, water pump, all belts, new vtec vlave assembly(including sensor), new knock sensor, new oil pressure sensor(located behind motor), new coolant temp sensor/switch(both), new pistons/rings (cylinders have been bored to .020 over? {20 over}, new front rear seals, new tie rods, ball joints, upper/lower control arms, shocks, new 8lb flywheel, stage 1 clutchmasters clutch, new transmission seals(ones for the driveshafts), new rear balance shaft, head has been polished/reworked while motor was being rebuilt.

Problem, can not get code to stay away when i reach over 4k rpms. I had the problem in 1st gear once i hit 4k rpm. I checked oil and it was fine but i added enough to hit the max fill line. Problem has now moved to 2nd gear at 4k prm. That does not make sense to me but at least you have the facts. Yes motor was primed before we started it for the first time. And ive already replaced all the parts that normally cause the p1259 to trigger in the first place. Only thing i have not done is take valve cover off, loosen all the head bolts and re-tighten. The mechanic has said he torqued them to correct specs at 22lbs then 90, 90, 90 degrees. Just like honda states for new head bolts. Could running recommended 5w20 in this motor after its been bored cause oil pressure to significantly drop? And to the best of my knowledge the oil pump works cause i have oil on top of the camshaft/valves or whatever the other parts are under the valve cover. Please help, cause this is my daily driver and have been without it for over 5 months. Plus my wife is going back to work in 3 weeks from having our first child. And car must be running. (i have spent over 4k in this motor and can not spend much more) I need good help from people who have experience this or have an idea of what could be wrong. I will be checking forums about 12-18 hours from now since i will be working, so i wont be able to quickly respond to any answers/questions. F23a1 is my motor year is 2000 LX 5spd. Im just tired, and can barely find it in me to continue without help. PS(took it to honda they were no help) told me what the code was and what to replace and said it might not fix the problem. And it didnt.
 

soccerchamp16

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Typically its either low oil, or the vtec screen is clogged. But since you just got everything replaced and topped off your oil im not sure. Maybe check all your connectors to vtec?
 

F23accordowner

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since I only get the trouble code when I'm driving I am pretty sure that the connectors are okay. I can try to double check that tonight. any and all help is appreciated.
 

Russianred

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If you already replaced the VTEC solenoid, I am unsure what could be causing it. Did you get regular or extra clearance engine/rod bearings? If clearance is increased in these areas, the oil pressure drops. Wondering if this could be the cause in your case if everything else has been ruled out?

Why did you spend $4,000 to rebuild with stock internals... :thinking:
 
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F23accordowner

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the mechanic said the rod bearings should not affect the oil pressure although the main bearings it is a possibility he said he didn't change the clearance with the main bearings and that I should check the oil pressure first to see if I'm getting the correct oil pressure. that helps a lot when I don't have an oil pressure gauge Nor a way to even know the correct oil pressure. if I were to get a gauge woul I need to check at the Vtec selinoid or at the oil pressure switch on the back of the motor. could changing my oil weight affect the oil pressure at all. like if I changed it to 10 W 40 instead of 5w 20
 

F23accordowner

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Re: Horrible P1259 SOLVED!!!!!!!

UPDATE! FIXED PROBLEM! Turns out the mechanic forgot to replace the bolt in the head that allows the v-tec system to work properly. Basically the left side of the head under the valve cover is a bolt that is used in advanced diagnostics for honda to check vtec oil pressure in the head. Removing this bolt and leaving it out causes the oil to spew out of it and not enter the rocker arms/ vtec assembly....this also causes all four of your Timing plates to break since there is no oil pressure to slide the pin back to disengage vtec, so when the plates return to there resting position (i believe) the pin is in the way breaking the timing plate. This all adds up to code P1259. This bolt cost me over 500$ in additional repairs after the 4k i spent in total rebuilding the motor and front suspension. Now good news is i am ready for my turbo application, sad part is i have a Tb2531 turbo, comes froms a saab. I can not find any specs on this turbo except that its motor mate was a 2.3L saab. And the motor produced 185hp. its a/r is .48 on the housing. Any advice on this....was shooting for 225-250whp with this turbo but this looks like its going to be a streeeeeeetch to attain that with such a small turbo. Wont have much turbo lag on the plus side. Btw motor has been bored .020 over. (hopefully i typed twenty thousandths lol)
 
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