Hi guys, I need some help to troubleshoot my engine problem.
When I start in the morning the idle is kind a lopey and after a few minutes it dies and hard to start back on again. If I get it start again it will die again after a few minutes. If the engine warm/hot it will take longer to die again.

Have a good sparks(new plugs), fuel pressure (42 psi)

test the plug wires resistance over 1000 ohm

Have new fuel filter,Relay and ECM.

Fuel pump sounding good when turn the ignition on.

When the engine dies the fuel pressure dropped to 0 psi and I checked the current on fuel pump relay connector was 12v.

Now I am totally Confused....help...help....help

 

How fast did it drop pressure? Leaking injector? Or ruptured FPR diaphragm, pulling fuel through the vacuum line attached to it. Run the motor, then shut it off and pull the vac line, look for fuel coming out and also smell for fuel in the line.

 

the pressure dropped kind a quick. When I started this morning it had the same symptoms and died after a few minutes. I changed the IAC, but didn't help ...
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Is this car has FPR diaphram...if it does where is it..?

I noticed something peculiar on the FP gauge when I start the ignition on, the needle sometimes drop to 0 and go back to 45 a few times.

 

IAC shouldnt have a hell of a lot to do with it based on the other things youre seeing... Can you hear the fuel-pump repriming when the pressure gets down? I dont think the computer has any way of actually measuring fuel pressure though so that doesnt make sense unless youve got a faulty gauge...

All cars have a fuel pressure regulator, at least that Im familiar with. Its on the fuel rail or remote-mounted, most are on the fuel rail, and they have a vacuum line. Their purpose is to raise fuel pressure when less vacuum is applied....and vacuum is pretty directly correlated to throttle position. Look for a round, stubby cylindrical thing attached to your fuel rail, with a small vacuum line hooked to it. That should be your FPR.

 

Oh that thing..I remembered now...last time I had a hard to start problem, I almost replace that fuel reg but that thing is kind a embedded to the body..?
so I cant replaced it. I did replace 3 of the injectors (low resistance).

 

As I said, run the motor, then pull the vacuum line. Look for gas and smell it. If it smells like gas, it has a ruptured diaphragm.

 

Ok...you want me to pull the vacuum line from behind the plenum..?

 

Pull the vacuum line directly off of the regulator, not from the manifold but from the regulator.

 

Ok...I am at work now..as soon as I got home I will do that..

thanks

 

I start the engine and pulled the regulator vacuum hose, didn't smell any gas fume...

 

You replaced 1/2 the injectors? Ohm them all again.

 

That the first thing I did when this problem started and replaced 1 more injector.I am thingking it could be injector leaks.

Last night I found fuel pressure 42-45 psi and good spark still could not start the engine.One more element that needed to start engine is air....

Do I need to check the air pump.....?

I will ohm the injectors again to make sure.

 

Air pump is not related....its aka smog pump, pumps air into the catalytic converters to help with the process.

If you floor it when you crank it, will it start? And were you careful not to tear any of the o-rings on the injectors when you installed them? You need to lube the orings with motor oil to keep them from ripping, will cause vacuum leaks

 

No..I did floor it..did not help ...now my question is, Do we need good spark or just spark to start the engine..? and the ohm on my plug wires is around 1000 ohm and from the coil is just 650 to 750 ohm is that acceptable..?

 

I took all the injectors out last night and ohm all of them (11-12.5 ohm) and also checked the volt (12v). the o-rings on injs look normal.

I put the fuel line back to fuel intake and let the fuel pump on (pressure 42 psi)
and no leaks from one of them.

How can I check the stream from the injectors without riskying my self with fire...?

Well...the challenge is still up there....anybody...?

 

Will it start up immediately after it dies? Does it ever have a no-start? Might be your Ignition Control Module overheating.

Check your ignition coil as well though...

 

Ok, when the Fuel Pressure drops directly to 0 when the pump stops, the chcek valve in the pump itself is shot. The only way to fix that is to replace the pump. A leaky injector or FPR will drop slowly, not immediatly.

Any time that you try to fire a cylinder you REQUIRE about 14KV to jump the plug gap. That's BARE minimum. I really need to write a guide to diagnosing no starts...I'm writing this TOO MANY times.

The fact that you have Fuel pressure is fine, don't worry about the drop back to 0, it amkes for hard starting, but it should fire after a couple of seconds.

Here's where people are completly misguided. A spark outside the cylinder, under atmospheric pressure is EASY to fire. It only take about 5KV to do it. Inside the cylinder, under compression, it's MUCH harder to fire a plug. It typicaly takes 14KV+ to do it on startup.

Coils only output what is required to jump the gap...if the coil is capable of it. Lets say for instance your coil is capable of putting out 10KV at this point.

When you try to fire it outside the cylinder, it only takes 5KV, so you have a POTENTIAL 5KV left, that'll give you a really good looking spark, but once you put the plug back into the cylinder and put some compression on it, it's only capable of 10KV, so it can't jump because 14KV is required.

There is a special teester available that is calibrated to take 25KV to fire a spark of under atmospheric pressure. Buy this tool at an auto parts store and NEVER trust just having a spark when you pull the boot off.

Coils tend to fail more when the engine is warm than when cool, but sometimes they do fail the other way around.

The AIR pump has nothing to do with air supply to the engine, it's just an emissions device, nothing more.

It sounds more like you are having a fuel METERING problem than anything else. FIrst thing you need to do is chcek to make sure that the computer is getting the correct signal from the MAF, CTS, IAT and TPS. Unplug each sensor, one at a time and try to fire the engine up. If you unplug one and it starts, then you know you have a problem with that sensor. You'll get a Check Engine light, but don't worry about it. The IAT is least important, so do that one last. Do it in this order: MAF, TPS, CTS, IAT.

See if any of this helps, then we'll go from there.

 

[I]I did find that 1 (one) of my injector ohm is 10.8 according to haynes manual supposed to be 11 - 14 ohms.

I cheked the ignition coil module at the autopart is good and also bought the spark plug tester to see if can produce enough volt.

Now I need to go to junk yard for the bad injector and check all the sensors

But so far nobody said about required ohm on plug wires.

thanks.[I]

 

<1K ohms/ft

 

Well... I just replaced the bad injector, put all back together and when started the engine now dont have spark at coil wire(engine dont want start).
checked the coil wire to distributor is only 700 ohm, checked the ign coil found is bad. Replaced the ign coil, fired up, still no spark at ign coil wire.

Now I am hopeless.....

 

Sounds to me like an ICM problem. Make sure all the wires on the coil and distributor are hooked up, then try it. If it still doesn't work, replace ICM. Even though it tested good, it still could be bad. I've found that the checker at parts stores is only about 50% accurate. I personally have had them check out good, but once I replaced it anyway, the car ran.

 

My bad I forgot to plug the 2 (two) sensors into ICM. I fired up this morning and the engine kind a hesitated to start. It start for a few seconds then went off then heard knocking or ticking sound from the EGR valve(Ign on).

I touch it to make sure is the EGR valve and it does the EGR valve that makes the ticking sound tick tock...tick tock...tick tock.

 

Finally got it fixed. I found one of the injector working intemittenly and car was running with 5 injectors.
Replace six of them with new.Now is running fine.

Thanks for all of you.