scope103

When you put in the new distributor, how did you set the ignition timing? Not every problem is caused by timing, but yours certainly could be that. With a $20 timing light you could at least say "stop bugging me, I CHECKED the timing!"

Shogun1332

Haha, should have mentioned it but when I put the new distributor in I reset the timing as per the FSM and then borrowed a timing light from a classmate. It was a little under so I adjusted it and got it set to the 10* specified.

Shogun1332

Well it wasnt the fuel pump, Just got it back in and buttoned it up but it is still doing the same thing. My buddy says that it might be bad injectors or clogged fuel rail...

Any thoughts? Much appreciated

scope103

... or a broken differential ...

You're both guessing. If you think you don't have enough fuel pressure, do you start by buying 6 new $200 injectors? No, that would make as much sense as buying a fuel pump. Start by measuring the fuel pressure at the FPR. Since that's at the end of the rail, spec. pressure there rules out any clog in the rail (or the fuel line or the tank). It would also be a good idea to check your compression; much, much easier to do than replacing a fuel pump or injectors.

Shogun1332

Alright, I'll try to borrow a fuel pressure test gauge from my school tomorrow and test it in the same day. I'll also see if I can borrow a compression tester to test the compression.

Thanks for the fast response, I really appreciate all of your guy's help

Co_94_PU

iTrader: (-1)

Shouldn't take near that long to warm up. Can you feel the hoses heating up and it's just not registering at the sensor? Pull and inspect the ECT(engine coolant temp sensor) and give it quick cleaning if it's not showing metal(copper brass, whatever it is). You cold start time switch is located in the same area, clean it also. Actually all of you temp sensors (I think) are located in the same area and could probably stand to be cleaned. (Steel wool, scotchpad, pocket knife, whatever you need to remove the scale buildup)

"suffocate" leads me to, have you inspected the air filter. Its not really "throwing parts at it" if you grab a new one, just think of it as prepared for the next tune up if it makes no difference you have a new one on hand.

Did you ever figure out the VAFM ohm reading issue? Was it a "user error", eg it's functioning normally and doesn't change readings when subjected to light vibrations and impacts or anything odd?

And finally you can have high enough(in spec) fuel pressure, but not enough flow. For example a pinched line the pump struggles to bring the system up to pressure the regulator or an injector opens pressure drops due to not enough volume. The manual doesn't list a flow rate for the cold start injector, but the system should be able to maintain pressure with it "firing"(eg open) for a moderate amount of time. But since you need to remove the air chamber to get to the pressure regulator(where scope recommended), might be worth the piece of mind to have the supplies on hand to check the primary injectors resistance and flow while you are in there.

Shogun1332

I pulled the codes today and it says code 31 which according to the forum is missing Air Flow Meter signal.
It has never thrown this code before, am I pretty much buying a new VAFM too? I tested it according to the FSM and it tested good, until I tested it while opening the vane, there it briefly spiked above the ohms specified.

When I get back from school today Ill check the air filter and the VAFM again. I suppose I should also start tearing apart the intake to check fuel pressures and clean those sensors, because they're under the intake right?

scope103

Try to do your diagnostics in order of difficulty. Obviously, you start with the "free" one: pulling the codes. Testing the fuel pressure (once you get there) requires a $40 gauge and the correct fitting, but you don't have to remove much to get to the easiest connection point. (You can't measure flow directly, but the pressure should remain within spec when you race the engine -- it should climb as you've reduced the intake vacuum.)

"Cleaning" the temperature sensors is a very difficult job; you have to drain at least a gallon of coolant, and you have to remove the plenum just to get to them. Since you can test the sensors directly with a multimeter, I personally would never remove the sensors unless I was planning to replace them. Checking the injector resistance can be done on the driver's side without removing the plenum, but not on the passenger side. And checking the flow of the injectors requires removing them and sending them to someone with the test setup to do it. So these tasks should be way, way down your list.

The VAF is expensive, but there are those on this forum who have successfully repaired them. It's not easy, but worth a try. But to be sure, if you're getting a code, that's where you're going to start.

Co_94_PU

iTrader: (-1)

I expect the VAFM connector is just maybe loose from having it off so many times, or just not fully seated. You can firm these female ends by pinching them back closed some, or lightly twisting the male end, recommend you don't tweak the male ends it'll expand the female ends eventually, but just for throughness.

Coolant system diagram is here, and the sensors should be easily accessable. Park it nose down and it doesn't need drained much if at all. You can also just jam a rubber plug, or screw in a bolt/plug, and do them one at a time. Since you're not likely making +40$/hr as a student I'd say clean em rather than replace them, you can also test them in a pan of hot water, resistence chart is in the manual.

Turns out you can get to the fuel pressure regulator w/o removing the upper-intake(aka plenum or air chamber)
Here is a pic. (Subtext Don't pull the air chamber or go thru the effort of testing the injectors)

Testing the injector resistance only tells you they're not shorted out or electricly damaged, not if they are pluged up. The injector flow test is in the manual, only requires a calibrated measuring cup, hoses, and the "SST" clamp and injector fitting. (You can DIY this with a spare fuel rail, zip ties and rubber hoses). Remeber 1ml = 1cc, so you can pickup a 1cup liquid measuring cup ment for kitchen use, and skip trying to source a "proper" flask, although a nice tall one would be ideal.

Anyways I mostly agree with scope, start with the codes!

Shogun1332

[YOUTUBE]http://www.youtube.com/watch?v=BczaZMiUR5w&feature=youtu.be[/YOUTUBE]

Shogun1332

Shogun1332

Hmmm I dunno if my pictures worked but anyway, I decided to test some more stuff today, I pumped the gas for literally 45 minutes and couldnt get it to idle, so I got out and heard that regulator at the end of the driver's side fuel rail, it was just going like crazy, I figured that it wouldnt let it build up any pressure in the rail so I pinched the fuel hose that comes off of it and, it started and idled. I took the vice grips off and it started to stumble but it still stayed idling and evened itself out.

I put the vice grips back on to see if that would let it rev up, it would let it a little bit but prolly only like 100-200 rpms.

I also noticed that with the vice grips on the regulator was leaking out the side closest to the intake plenum.

Maybe its nothing but it occupied me and I was excited to see something change the equation a bit

Shogun1332

I also took the hose off of that regulator, it shot fuel all over my garage

My school didn't have a fuel pressure test set for a gas engine, or a compression tester for a gas engine. So i'll have to wait until I can get a ride back out to Napa to see if I can borrow those tools.

andy4x4

timing off?

Co_94_PU

iTrader: (-1)

Need to use the "IMG code", second one from the bottom.
Video is a great idea, but you have to remeber to preview it first We can't hear you if you're leaned over the fan.

There are a couple of spots it sounds like a vacuum leak sucking air, 46sec is one 10sec is another, but it's hard tell. try not to let the fan blow on the mic, eg but your hand between the two. If you wanna try the video again try and keep the camera on the engine, and hover/focus on the vacuum components

Attached is a color coded vacuum map so you can give it a once over.

Again it shouldn't take it so long to warm up, lie to the computer and put a resistor in the plug for the ECT sensor 200-1000Ohms after about five minutes. Don't run it like that forever obviously it's just so you don't have to stand around for an hour waiting. Of course you didn't mention if you can feel the heat in the radiator before that 45min, you can turn on the heater and tell from inside the cab assuming you can't get out away from the throttle pedal.

Shogun1332

Haha, I tried to preview it first and thought it was a bit shaky but I thought I did most of the audio okay. Ill try to do it again tomorrow after my classes there is one vacuum leak that I know of, its from the plenum to the power steering pump. it effects the idle but only a couple hundred rpms.

I think the thermostat it bad, stuck open or something, cause I can't get any cab heat until the gauge gets to the middle area like in the picture. It's a little low on my priorities right now though. It'll get fixed eventually.

I'm more interested in the return regulator? Is that what it is? Why was it letting so much fuel through? Could that cause this problem? like it isn't allowing fuel pressure to build up so fuel just goes straight through the rail and back to the tank? I dunno, that's what I'm kinda thinking, had the same sorta problem on a 16 litre volvo i've been working on at school, to start it we had to pinch the fuel return line to fake it into thinking it was a reduction orifice, however we had to keep it going with ether because it wouldn't even idle on its own

Ill check the vacuum stuff tomorrow as well, thanks CO_94_PU

Co_94_PU

iTrader: (-1)

Easy checks for the "fuel pressure regulator", pull the vac line off the top and it should close the valve, disconnect the electrical plug at the VSV it should close. There is a whole proceedure listed in the book, suck here blow there resistence, all that fun stuff

Can't really say conclusively whats going on there with the fuel pressure. it's 38-44 reg' closed, 33-37 open.

Does the gas tank suck air when you pull the cap off? If so it shouldn't, that'll be a faulty gas cap. I don't recall offhand if you already replaced the filter and inspected the lines.

I'd worry about that thermostat issue sooner rather than later, ~10$ doubles your available working time to debug this problem. or something.

Definately do something about that vacuum leak too, even it's just pulling the line and pluging it with a bolt. ECM will detect it as running lean and open the injectors longer, at which point it could be flooding or just throwing the air/fuel ratio off enough to not combust.

BamaYota1

Do yourself a favor, when you know you have a problem like a vacuum leak or a faulty afm, fix it immediately. When troubleshooting, you need to eliminate problems as you get to them, not making a list of what you need to do.

First and foremost, go over every vacuum hose on the motor and make sure it goes where it is supposed to go. Co 94 have you a chart, use it!

After you check hose routing, use starting fluid to find any leaks. If you find one, fix it right then and there before moving on.

Next start at the airbox and work your way back to intake checking every component for function and the air line for cracks and leaks. You know the afm has a problem. Fix it! Check the wiring like you have been asked to do as well.

Address these two problem areas before you do anything else.

I'm not trying to be a jerk, cause you seem like a nice kid who is trying his best, but you are going about this all wrong. You are shot gunning the engine instead of methodically troubleshooting. You have to stop. You've been at this for a month now, and made little progress. You've got to stop chasing squirrels and focus. If you do, the big problem facing your engine will be the last component you check.

uncleblues

chill, grasshopper...take a deep breath
sounds to me like you are overanylizing the problem, and making a lot of guesses

an engine needs three things to run
air, fuel, spark-so-one of these are missing
do you have spark? sounds like you have enough to start, but is something interfering with this after it starts?
is your air filter clean? Is there something else interfering with air flow? I had a motorcycle that died on me once, turned out I had sucked a paper napkin into the filter box..
might be your fuel filter is clogged, not completely but just letting enough fumes in to start but not to run
look at one thing at a time, and when you are satisfied that a component is functioning properly, move on to the next-or, as Mr. Holmes said, when you run out of suspects you are left with the culprit
good luck

Co_94_PU

iTrader: (-1)

Here is the quick list of whats been fixed or replaced. I might of missed some but don't think so..
And here are two easy things that still need taken care of
After fixing the vacuum leak, and replaceing the thermostat. Test the voltages at the ECM per the manual, page EG2-254&255. Post readings of VC VS and THA, these are the VAFM, you need the readings "switch on" "idling" and "3000 rpm" We know you can get to 3k so "while applying throttle and it starts to die" will have todo

Good luck and stick with, you've made progress and will continue todo so!

P.S. Don't forget to answer direct questions like "How is the air filter"