Ka 510

[fiveNdime]

I have a 95 KA with a 91 harness in my 510. The whole motor is fresh from machine shop. everything on the motor is right. Problem: Car wont start good.....acts like a carb'd car....have to pump the trottle when its cold but when its hot it starts better. Car sometimes loads up and dies when sitting at idle after I first start it. Also seems like its running rich ALL the time. And doesnt have near the power as my dads KA which is a stock 91 KA.

 

Remedies: All I can think is its a coolant temp sensor or thermostat? May be bad injectors or something in the ignition system too I guess.

 

please help...

[tiltnose510]

Well, first of all, it's never going to have the power of the '91. The '91 has bigger cams which seem to run out somewhere around Christmas Time. They are sought after by enthusiasts of the KA..DE.

First, pull the fuel rail (injectors still in) and turn the ignition on to see if you have a split injector o-ring.

After that check to make sure the ECU pug is tight. I will see if I can find info between the ECU / harness that might cause a problem. The code on that ECU should be 24? 28?

What code is it?

Mark

[Icehouse]

I'm with Mark, check those codes. Also did you hook up the cold start wire? Orange on the s13 harness, I'm not sure if its the same on the s14 harness. Have you cleaned your maf lately?

[BEEBANI]

I kind of have a similar problem with mine, takes a couple of tries when cold to keep it running. How exactly do go about checking the codes? The book doesn't really explain it very well.

[tiltnose510]

There is a little dial thingy on the side of the ECU which you turn all the way to the right (with the ignition on) and then turn it back to about the center and it will then flash out the codes. One long flash = 10, one short flash = 1.

If it is "all clear" you will get 5 long then 5 short or 55.

[nismopu]

Joey, I agree with everyone else on here about checking the codes but the VG's have similar problems when the CTS is bad. So, run the codes and let me know what it comes up with. BTW did you ever get the FSM from carfiche.com? peace.

[fiveNdime]

I have the 91 cams in mine so it should run at least close. I also have a header on mine and a port and polish not to mention its been bored out when it was freshened up. Cold start wire is hooked up. Plugs are all tight. I pulled the fuel rail and Have no leaks. I havent checked the codes.....so thats next. Nope to kyles qestion! Thanks for the Info everyone!

[tiltnose510]

Try checking the resistance on all of the injectors. They should be somehwere between 12 and 14 ohms. See if any of them are way off, It's a stretch but should be checked. If one of them is bad it can cause the others to mis-fire. Also, if there is a code and the mafs or fuel injection temp sensor is bad it will cause the ECU to run in "limp home" mode which would make it rich all the time. The FI temp sensor is the one with a two prong plug next to the gauge temp sensor. Does it have the vacuum actuated secondary butterflys on the manifold? I thought that the later ones did and they may not be connected or opening. If it does, try manually opening them and see if that has an effect.

Mark

[vgwagon]

Maybe check the compression or leak down of each cylinder....o2 sensor could be lazy, check for poor engine vacuum, maybe cam timing is off, or ignition timing could be off.

The 95 motor shouldn't have the butterflies.

Maf could be dirty.

Fuel pressure could be too high, or a blockage in the return side.

You mention the engine is fresh, maybe it just needs to be broken in?

[nismopu]

Maybe check the compression or leak down of each cylinder....o2 sensor could be lazy, check for poor engine vacuum, maybe cam timing is off, or ignition timing could be off.

The 95 motor shouldn't have the butterflies.

Maf could be dirty.

Fuel pressure could be too high, or a blockage in the return side.

You mention the engine is fresh, maybe it just needs to be broken in?

 

o2 sensor shouldnt be sampling during warm up or at all if the cts is bad. Cam timing is unlikely I know joey like triple chacked that after the frist tear down and finding the cam bolts loose. Part of the reason for the fresh rebuild, among other things. Yeah, i remember having an issue with a 240sx that had hard times starting and it was fuel related (bad FPR) but it was actually flooding the engine very badly!! DOnt think this is the case because your running an aftermarket unit but with a stock rail right? peace.

[fiveNdime]

ok...lets see here. No vacume leaks, 02 sensor is fine I, Fuel pressure is spot on at idle and under load conditions, didn't check the ohms on the injectors yet, Intake is not the butterfly one, no blockage on return side of fuel, four 20 min sessions at PIR....its broken in for sure...I have around 400 miles on it, Timeing of all sorts is Perfect...all the electrical parts are also good, Could be running on limp mode......Should have just built an L motor....hahaha Thanks again guys for the help....cant wait for it to run better.

[fiveNdime]

Did a bit more work on it today. I put a new coolant temp sensor in it. That made it run a bit better. I took out the aftermarket fuel pressure regulator and went back to stock. It seemed to run even more better after that. I then played around with the idle setting which it was idleing low but that obviously didnt help. My next thing that I found out was surprising. I have my coil, injectors, distributor and MAF hooked up directly to a 12volt line as soon as I plug the battery in. That was just to get it running but I found out that if I leave it plugged in it doesnt start good and I have to pump the gas a bit. If I unplug the battery and wait a minute then plug it in then start it right after it fires right up. Maybe the MAF is getting too much voltage and heating up when I leave the bat hooked up..........If you know anything different let me know. Thanks

 

ooh ya almost forgot. I unpluged the O2 sensor and it ran better???????

[510six]

Have you checked the MAF voltage at idle? The first thing I would do is to make sure all of the wires from your coil, injectors, dist and MAF go to the correct pins on the ECU. Double check all your connections, sounds like the ECU is in "limp home" mode.

[Icehouse]

Is the bolt nice and tight on the ECU? Thats about the only thing someone hasn't mentioned that I have personally ran into a few times.

[fiveNdime]

Yep, bolts tight. I havent checked the voltage with the car running, only with the car off and the key in the on position. It has around 12 volts. Its again an OBD1 system. I dont think its too bad cause the ECU's not throwing any codes. All the wires are in the right spots.

[fiveNdime]

Finally wired in the relays. Now the coil, dizzy, MAF, and injectors have power when I turn the key on and not all the time. Still have to drive it to make sure its running better.

[fiveNdime]

Well I think I have found out some of the power loss with my KA. I had a theory about my stock FPR or Fuel Pressure Regulator. I was running an MSD fuel pump which pushes more fuel. Problem is is that I have found countless guys running them with there stock KA's. I happed to have a spare fuel rail with one on it so I checked the pressure with the old and new and they were the same. They weren't bad, because they tested fine, its just that the pressure was too high. I had an Aeromotive laying around so I threw that on there and its now fixed. I forgot to mention that the voltage to the pump was also fine, and all lines were clear, and filter is new. It now has a bunch more power but still isnt to its full power yet. Now I am leaning toward the clutch slipping? Its a new Exedy, but that dont mean anything I guess, just the fact that it should be better or at least the same?