KA24DE Missing/High compression

[bimmer96]

Ok so i did a compression test and it came out to 210 with the throttle closed. no idea why its so high. tested without the exhaust same thing. then it started doing something new. it now acts like its starving for gas when it gets warm. itll start doing it at 3500 and then just gradually work its way down so it cant idle and if you give it gas to keep it going it just acts like its starving. its getting gas so im not to sure what to do. and its been running kind of warm. i threw a egr code but i havent gotten it again after i cleared the codes a week ago so any ideas

[del82]

Don't suppose you bothered to actually check the function of the EGR valve when you got the code, did ya? You can do it with a vacuum pump, just hook it to the dashpot on the EGR valve and pump it up to about 12 inches of vacuum, it should almost kill the engine, if not kill it outright. If it doesn't really change the idle, you'll need to replace the valve.

[bimmer96]

Don't suppose you bothered to actually check the function of the EGR valve when you got the code, did ya? You can do it with a vacuum pump, just hook it to the dashpot on the EGR valve and pump it up to about 12 inches of vacuum, it should almost kill the engine, if not kill it outright. If it doesn't really change the idle, you'll need to replace the valve.

well right now its dropping the 3rd cyl when it gets close to being warm.. ill try it and see what happens when its cool

[1KleenS13]

Good point for checking the EGR. What are your plugs gapped at? What CR is the motor?

[bimmer96]

Good point for checking the EGR. What are your plugs gapped at? What CR is the motor?

they are iridium so no need to gap. supposed to be at 180 psi but it was 210 psi throttle closed and 230 open. i dropped it off at nissan today. hopefully its something simple. i just didnt have time to deal with it right now. hate spending that much money but itll be good to know what is wrong exactly lol.

[bimmer96]

so the dealer said it was the the whole distributor assembly and its like 800$ to replace it....

[del82]

so the dealer said it was the the whole distributor assembly and its like 800$ to replace it....

Its plausible, but its not actually the whole assembly, they just have to replace it as a unit, if you were wondering

Also, dealer prices are always high because you're getting factory replacement parts, as opposed to off-brand, which has always struck me as odd because you can get the off-brand stuff with lifetime warranties and such...but anyway, go for it if you have the cash.

[yoesh1]

I'm not sure about the rest of your symptoms, but the 240sx I bought from my friend had a bad injector on #3... The problem first started appearing intermittently, only when warm. It would run fine until it came up to temperature and then #3 cylinder would drop and the car wold shake like a motherf***er. Just wanted to throw that out there. It eventually stopped working completely, cold or hot.

Good luck with your problem. I'd sure like to know what could cause your compression to be so high!

[bimmer96]

ya i know im getting a dizzy from a scrap yard tomorrow. we use them at the bmw shop a lot for odd ball parts never have had anything bad from them. 60 sounds better than 800 lol.

ya im at a loss on the compression. ill figure it out when i tear it down and rebuild it. wish i had time to now lol but leaving in 30days for basic training.

good to know that about the injector. i think ill go test them here in a few. and is there a way to test a cam position sensor. iv been trying to find out all day and only have found crank sensor stuff. i know on bmw's you can.

[bimmer96]

injectors spec out... is there a way to run a obd1 dizzy with a msd coil setup?

[del82]

injectors spec out... is there a way to run a obd1 dizzy with a msd coil setup?

MSD probably makes a kit for it. I had a supra with a MSD 6A on it awhile back, and I had to buy an extra bit with it so my tach would still work. If you're thinking of putting an ICU on it though, replace the coil while you're at it, even if it doesn't come with the kit. Particularly with MSD, cutting the available coil charge time in thirds puts a strain on the coil. I got to test mine with some school equipment, and I was losing almost half of my spark power just cruising at 60mph with the MSD setup, before I picked up a new coil. Causes some running issues, hesitation, etc.

[bimmer96]

ya i can find a obd2 dizzy cheap lol... its the cam sensor that the dealer says is bad thats why i wanted to run a obd1 dizzy with a msd or something

[bimmer96]

the tps just turned out bad its pretty much just all or nothing ... so it threw cam sensor code and the tps is bad too .... im starting to miss my bmw now lol