97 Mazda B2300 (we all know it's really a 2.3L Ranger) looses compression briefly after being revved and released, then corrects. MUCH worse cold than when FULLY warmed up. After idling 2 min from a cold start, if revved and released, engine stalls and seems to have NO compression upon immediate restart. Compression returns after a 10-30 second pause and then starts and idles fine. At full operating temp, will misfire and loose power (when revved and released from idle) but then recovers within 2-3 seconds. Oil pressure hot : 25@1000, 53@2000, 58@3000. OP cold: 50-70@1000, 65-70@2000 and tends to stay up fairly high until oil up to full temp.(about 3-5 minutes of solid driving beyond the point when the water temp gauge no longer rises) Compression check normal in all 4 cyl.
Replaced: valve springs, seals and lifters with no improvement. Two (intake side) spring were slightly weak and the valve seals were worn out. Went for the original Ford HLAs ($21 ea) instead of the $6 Sealed Power ones.With springs removed noticed # 1-3 intake valves were sticking at the top (closed) end of travel. Soaked them overnight by putting a piece of tubing over the casting nipple that surrounds the valve guide and filling it with Seafoam. This freed them to the point where they could fall under their own weight but still felt a little "dull" when pulled up sharply (compared to the exhaust valves). Looking into the intake rallies saw very little carbon on the chamber or valves and none on the stems or bottom of valve guides. Read somewhere that normal pressure should be 20-25 at idle and 40-60 @ 2000 but could not find specs for @ cold. Stumped at this point but wondering if a high volume oil pump had been installled and if that could be causing the lifters to over pump at high rpm and hang the valves open when rpms drops down.
Truck had this problem when I bought it and do not know the history of the vehicle.Fresh 5W-20 oil and new Fram filter.

 

what fixed it I have an 87 ford ranger 2.3 just had the engine rebuilt now it will run for a few seconds and lose compression and die has over 100psi oil pressure

 

has anyone ever heard of anything like this I have pulled the motor three times and takin it back to the machine shop that built the engine they have installed new oil pumps and no change I pulled the head and took it to them they put a new cam, lifters, rocker arms, and oil relief cam bearings in it got it put back together same problem run for a few seconds lose all compression and die. I installed my snap-on oil pressure gauge and it pegs the gage at 100psi. let it set for 30-45 min it will start again for a few seconds. ANY HELP WOULD BE GREATLY APPRECIATED NEED TRUCK FIXED

 

The oil pressure relief valve is most likely problem.

Either stuck close or assembled incorrectly, I believe it is part of the oil pump assembly on the 2.3l, although I could find no supporting documentation for an "oil pressure relief valve".

Oil pumps are designed to provide more oil flow than is needed for the engine, so a relief valve is used to prevent what you are describing, usually set for about 60psi, it would open at higher RPMs and some of the oil flow going to the filter would be redirected back to the oil pan.
It is usually a simple spring and ball type valve.
The wrong spring or stuck ball means full volume or oil at high RPMs goes to filter, this can balloon the filter.

I didn't think the 2.3l OHC had hydraulic lifters

 

this is an 87 model ford ranger is does have hydraulic lifters and we have put three different oil pumps in it with the same results. the oil pumps were order from three different places.

 

the machine shop recommended rotela 15-40 for engine oil then they order straight 5w engine oil and nothing change even with super thin engine oil still has over 100 psi of oil pressure. this oil pressure reading is at idle and in place of the oil sending unit(pulled factor sending unit to install manual gauge)

 

I have never disassembled a Lima engine so can say where to look for the oil pressure relief valve, it has one, has to.

The timing belt turns the oil pump gear with AUX shaft for distributor, if so equipped, not sure if the is a reduction gear for oil pump or if it spins 1:1 ratio with timing belt gear.
Common place for relief valve is on the oil pump housing, either part of the pump or the housing the pump bolts to.
The oil pump pumps oil to oil filter housing through one passage, another place for relief valve, I would remove this oil filter housing and check it.
I doubt the filter could be the problem, filters have a by-pass in any case.

I doubt the passages are blocked, i.e. spun bearing, because you are getting "real" higher oil pressure if lifters are causing lost compression, and a blocked passage would still not produce 100psi since relief valve should limit it to 60psi

 

Hi. Did you ever figure out the problem? I have a 97 doing same thing.

 

greetings I ask you to solve the problem since I have a mazda B2300 1997 with the same problem if I found the problem I would appreciate if you could tell me how to solve it Thanks