Hey guys,

Today I was driving my 2000 max 5spd with 94k all day. Parked the car for about 4 hours and came back to a no-start. When I can get it started, it is misfiring VERY badly and will stall without gas. It was puffing smoke too (looked white-ish but it was at night) and you could definetly smell gas.

- Coils - Swapped coils around, thought it was a coil, but I couldn't single out a bad one. Have not ruled this out yet. How can I test these?

- Injectors - Not much experience with trouble shooting, but I do have an afpr with a gauge. Once the car turns off fuel pressure almost instantly is at 0 psi. Does this mean an injector is pissing out fuel and hence not maintaining pressure once the pump is off? Any other things I should check on?

- Maf - This shouldn't cause misfiring if its bad right?

- Plugs - Haven't pulled them out (I was doing parking lot diagnosis) what should I look for that could give you guys some help? They are Denso Iridiums that were installed around 70k (I have 94k now).

- Compression - I will be checking this shortly.

Anything else you guys need please ask. If I can't figure this out easily I'm considering pulling the fuel rail to see if one of my injectors is stuck open.

Thanks a ton,

DF

 

Any MIL codes?

 

Checked the crankshaft positions sensors?

 

Codes

- P0300 - Maf, I unplugged it a couple of times, so I have this one

- P1320 - Manufacturer control ignition system or misfire

- Pxxxx - Random/multiple misfires detected (can't remember the number)

Have not check the CPS, how do I check that?

DF

 

Unless you unplugged while the car was on, it shouldn't give you any MILs
They're related. Have you replaced your coils since you owned the vehicle?
If there is no code, it should be fine. You can check resistance. Refer to your FSM what the spec should be, but I also reinforce, if there is no code, it should be fine.

 

MAF was unplugged while it was on.

I've only replaced two, I have 4 without the grey dots and two with. I swapped around the coils though and all of them seem to be fine. How can I test these coils?

What about my fuel psi dropping instantly when the pump is off?

DF

 

Bump, pulling plugs tomorrow should the plugs just be soaked in gas or will there be some other telltale sign?

Any input would be greatly appreciated, I'm probably going to pull the rail to see if one of my injectors is stuck!

DF

 

Check the crankshaft positions sensors.Is it takes a long time to start your car? To check your ignition coils: start your engen, and unplug coil, plug it back. Do it to all coils.

 

Seems like common knowledge, unless I'm missing something.

 

My buddy claims that I should be holding some of my fuel pressure once the pump is off, not having it instantly drop to ZERO psi. Can someone confirm this for me?

And, my car doesn't run well enough to get anything from unplugging the coils. I finally found the FSM I had and will be going through the misfire procedure today.

DF

 

Today: Put in new Bosch Fusion Iridium plugs and started her up....still misfire. Pulled each coil individually and put a spark plug in it and grounded it. Every coil does the same exact thing when turned over.

Coils = OK
Plugs = New

Still misfiring like a bastard. I used a piece of tubing to see if my injectors were opening and one does not seem to be clicking. I will probably pull the injectors off tomorrow.

Can I crank over the motor fine with no intake manifold?

DF

 

BUMP!!!

Can someone confirm the fuel pressure question.

DF

 

Only use NGK plugs. I have read about plenty of misfires/rough engines with non NGK plugs.

 

I've had Denso Iridiums in for 10k. I haven't had an issue with them at all. Can I get some part numbers?

DF

 

Advanced auto NGK vpower, 2 dolla a plug.

 

Too simple a question for this forum, wouldn't you agree?

 

Can you unplug your MAF and start the car? See if that does anything.

 

You need to get a lab scope and check the sine wave of the injectors. It's not the easiest thing in the world to do, but it will show you if an injector isn't firing, or if a coil is malfunctioning. I suggest testing each individually and look at the sine wave readings. But since you most likely don't have a lab scope, I suggest the following:

Test the coils first:

You can check each individual coil by disconnecting one at a time while the engine is running. Make sure you go one by one. If you disconnect, and the idle drops, the coil is working. If you disconnect, and the idle remains the same, the coil is not functioning properly, replace it. I honestly think that you are having a coil problem whether you know it or not.

If this previous step doesn't work, go on to the injectors:

See if one isn't clicking normally. This isn't easy to do on the rear injectors, but my suggestion would be to verify that the front 3 are working, and if they are, swap the rear injectors with the fronts, then see if any of those ones (the rears which are now on the front) are not clicking.

Other suggestions:

Make sure you have gapped your plugs properly.

Pull the plugs after the engine has been running for about 10 min with the misfire problem, and see if any plugs are fuel soaked (this would mean a coil problem, this is helpful if you find that all your coils are firing with the coil test, if a plug is fuel soaked, replace that coil).

If you are STILL having a problem, check in this order: Crank and cam sensors (though no codes should mean no problems, the P1320 code can be related to the flywheel sensor), do what Tatanko suggested, unplug your MAF after starting the car, and see if the problem goes away. If it doesn't, plug it back in. From what you were saying, it doesn't sound like your fuel pump is malfunctioning if you are smelling fuel, that leads me to believe that your plugs aren't firing correctly, causing unburnt fuel. Last thing to check is the TPS (this is a last resort, you should've found your problem by now).


Just a little bit of help I have to offer.


EDIT: Just noticed that you tried unplugging the coils. Skip that part for now.

You may be losing fuel pressure because one of your injectors is "stuck" open, causing fuel to be dumped into the cylinder, which could cause smoke and could also cause the fuel smell you are experiencing, not necessarily the answer to your problem, but a theory.

 

Good looks man, I'll be swapping the injectors tomorrow morning. Anything special about pulling them or reinstalling them? I've never touched them before.

DF

 

Make sure you don't tear the o-rings, and ALWAYS make sure the rings are clean before and after installing them back onto your lower IM. You could make problems worse if you don't reinstall them correctly.

 

Your freind is correct........

 

If the injectors click when I put 12 volts to them they are good correct?

So far,

Injectors - all click, proper resistance
Coils - All have proper resistance, all produce spark with spark plugs grounded
Plugs - Brand new

Now, I do have another concern. I just recently uninstalled my SAFC. Would any of the wires that I tapped into produce this effect if they somehow were broken/grounding out?

Can a broken/grounded wire make an injector stay open?

DF

 

Yes, if an injector wire was grounded between the ecu and injector it would stay open. You have a couple options, start with an ohm meter obviously, you can also pull the rails, and test in a bucket to see if any are sticking, HOWEVER, what's up with your fuel-pressure, ie what is it at, and where is your gauge located? You don't have your stock fpr laying around do you, it would be a quick easy step to throw it back on, that's where I would start......

 

Hollowed out the stock fpr.

Fuel psi was like 2 psi above stock, but I changed that back to normal. I have the gauge in the AFPR, but I do have the IM off.

Will anything shoot out of the injector holes (in the block) if I crank the engine over with them out?

DF

 

Air, that's about it...unless you have some puddled fuel in there, which I doubt.

 

How should I check the out put of the injectors? Cup each one individually and check how much they put out for a certain amount of time?

DF

 

Ok so today I pop in a new maf and the car turns on and sounds like normal. Granted I do have a GIGANTIC hole in my y-pipe flex section. I take the car for a ride the car runs beautifully and I get really excited.

I take it up towards redline in first and second gradually and there is no misfiring to be felt. I then get a little more aggressive and work my way up to full throttle and everything's OK!!!!

Get back home and it starts idling weird and then when I try to rev it giving it around 15% throttle it gets really rough and holds 2500-3000 rpm. Then, it stopped and was fine again.

There is a leaking sound, but I can't really tell where its coming from. It could be my short intake, as that makes a ton of noise. It COULD be coming from the top of the manifold, but I checked all the hoses running on top and couldn't find a thing!

Do the manifold support bracket bolts go all the way through the manifold? I didn't put these back on yet and was wondering if I could be suckin in from there.

EDIT: Almost forgot! There is a faint haze of black smoke at idle and at any cruising/wot speed. This did not happen before this whole incident.

DF

 

Oh, sure, don't listen to the advice I gave almost 2 weeks ago
Nope.

 

Well, I happened to get one for really cheap so I figured I'd try it out.

What about it having a rough rev-up at random times? Could this be a coil that is on its way out?

DF

 

New stuff!!!!!!

Out of the fpr's vacuum port there's fuel!! Its really coming out somehow and going directly into the intake.

DF

 

oh, sure, don't listen to the advice I gave almost 2 weeks ago. There is one thing that causes that.......

 

I'd taken off the line before and it didn't **** fuel at me. It only does it randomly somehow, but when it leaks its really bad. Car seems to be back to normal now and I'll post how she is once the new fpr goes in.

Just so everyone knows, this is an Aerometer fpr that was brand new.

DF