Engine want's to start, but won't fire

[apex_240sx]

alright guys, here's what happened: i'm up here in sask. canada (very very hot prarie summers) and ya..i'm on a gravel road, travelling at 80 km/h (or about 50 mph) and my engines rpm's instantly drop from 3500 rpm to 1200 rpm, and they won't go back up!!!! so i pull over thinking that the engine overheated, but then i noticed that my engine temp gauge was in normal range. so i just sit there and wait for about 10 minits to let the engine cool (i'm thinking that the gauge might be screwed) and i start the engine fine, but still the engine wouldn't rev past 1500 rpm. At this point now, i had to push the gas pedal about half way down just to keep the idle at 900 rpm, and so it wouldn't stall on me. So i just stay there on the side of the road, call a buddy and get him to tow me to his farm about 10 minits away. once we got there, i tried starting it....and it wouldn't start!!!. so the next day i got it towed into town and got a diagnostic done on the engine (the engine was firing fine and the diagnostic showed nothing wrong with the engine) and a compression test was done (and each cylinder reported 130 to 135 psi which is normal for the KA24E. So then i towed the car home and have been checkin a few things out for the last few days here and i still can't get it to start. The engine will try to start, the starter is engaging the flywheel, but it just won't fire!!!!! Does anyone know what could possibly be wrong, cuz i sure the hell don't!!!!! P.S. the plugs are fine, they're sparking good. the fuel pump is working fine, and the fuel filter i just replaced a few weeks before this all happened. I sprayed carb cleaner into my mass airflow sensor (i read on a forum on 240sx.org that spraying carb cleaner into the mass airflow sensor could solve my problem) and that did nothing. So please give me any advice if you can....thx

1990 240sx hatch KA24E w/200,000 km's (or something like 120000 miles)

[tkrolo]

It sounds like a fuel system problem to me. If the ecu isn't throwing a code, you may just have to go down the line checking all the fuel related components. good luck

[DuKyle Motorsports]

I had a similar problem with my freshly rebuilt 89' ka24e. I knew that there is no way it could be the engine, and we were about 145-150psi range on all 4 cylinders. We checked all over the engine and couldnt figure out what the deal was. It turns out it was the EGR valve. We read the CHILTONS repair manual forever to figure this out, but it had a good chart for locating and testing it. Basically, there is a round bronze colored disc behind your throttle-body. Its very tight to the firewall and will be hard to replace, but test it first. There is I believe a rubber hose and a metal pipe connected to it. You should remove the rubber hose and blow on it as hard as you can until you hear a pop (I used a air compressor). Now try cranking your engine. It may be a little rough, but try it anyway, if it seems like the problem is fixed, then by all means buy a new EGR, about $75-$100 U.S.D., I think this should help you, but I suggest you read more about it in the CHILTONS repair manual if you have one. Good luck with it man, I hope this helps out some.

[drjohn]

It sounds as if you have a ignition timing problem. If engine has high milage I have seen cases where the dist. gets out of timing. This can be checked by removing the dist. rotor and checking the screw in the dist. shaft under the rotor button. This allows the trigger wheel to loose it's index point and retards or advances the timing. You can remove the screw and see the index marks on the trigger wheel and the detent tab on dist. shaft. Just re-align and re-assemble and if this is the case you'll be good to go. On very rare cases the oil pump will lockup and twist the drive shaft to the dist. and the timing will be out.

[apex_240sx]

thanks for your help guys, but i have finally isolated the problem.... it was my fuel pump. it wen't into vapor lock. it was still pumping fuel into the engine, however only at about 2-3 psi, where is should be doing about 35 psi....so it was still giving the engine fuel, just not enough to start. so thanks for the help guys...in the future, i will definitly post any of my problems, questions, or concerns on here...thx.