It Won't Start

[tmorgan4]

Unfortunately the weekend is coming to an end and my VH45 still isn't running. I'm having a hell of a time finding out what is keeping it from firing up, so I'm hoping that some people here might be able to try and give me some suggestions.

I'm fairly confident that the problem is a lack of FUEL. I did confirm that cylinder 1 has a spark and I'm pretty sure that all other cylinders should have spark too.

I added 5 gallons of fresh gas and replaced the fuel filter. The pump IS coming on exactly as it should, and pumps while cranking. The problem seems to be somewhere in the fuel rails or injectors, whether they're not firing or ???.

The main reason I suspect lack of fuel is that I have a wideband O2 setup installed, which normally sits at 22.2 with the engine off. While cranking, it only drops to 16 or 17, while I'd suspect it to be MUCH richer when starting than 16:1.

A couple questions:

Can anyone confirm which of the 2 hard fuel lines on the engine is the inlet and outlet? I tried both configurations (and had plenty of fuel pressure, I had to bleed off tons of pressure) but neither worked.

How can I be sure the injectors are firing. The FSM mentions to listen to see if they're firing, but I can't hear the click of an injector over the engine cranking.

Is the injector harness grounded itself? There are 2 plugs that go to the injector harness from the main harness. The small 4 plug connector that has 3 pins has 2 power wires and 1 ground. The two pins show 12V like they should, but the ground is non-existent. When probed from the injector harness side, the injector harness shows a strong ground! I don't ever remember grounding the harness.

Sorry for the long post, but I would appreciate it VERY much if this board could help me get this thing running. After 9 months of working on it I'm starting to get burnt out and just want it to run. If you notice anything out of the ordinary above, please point it out!

[gs14racer]

The injectors get switched ground from the ecu and constant power from the harness. Make sure your CAS is getting power.

[tmorgan4]

Thanks Jerry...I will check on the CAS specs and I'll make another run at it tomorrow. Burnt out for now.

[gs14racer]

also make sure your start signal wire is getting switch power from the ignition switch.

[RichZilla]

Pull a couple of the plugs out and check them. Are they wet or dry? If they're new plugs, wet means no spark (or weak spark) dry or clean means no fuel.

The best way to hear if the injectors are clicking is to go down to your local auto parts shop and buy a stethoscope. Place the metal rod on top of the injector while you get someone else to crank the engine over.

[tmorgan4]

Good advice. I tried listening with a screwdriver like the diagram in the FSM shows but couldn't hear over the engine.

I will try pulling that #1 plug and see if it's wet. They're brand new OEM plugs from the dealer that were already gapped. I'm sure that #1 cylinder is getting a spark as I pulled the coil off the plug and attached an old spark plug wire with an old plug, set it near some metal in the engine bay and watched the arc while cranking.

Finding out whether the injectors are firing at all or weakly is going to be key.

And...can anyone else find the specs for the CAS? I looked quickly through the EC section and didn't see it listed, but I know I've seen it before.

[tmorgan4]

I finally managed to get my Consult cable hooked up tonight and it helped me look at some of the data from the ECU. I ended up starting a thread in the Q forum and I know some people will want to slit my throat, but at this point I don't really care.

One thing I noticed when typing out my post there is that my injector duty cycle is reading 2-3% while cranking, with a steady 26 number that I'm assuming is pulse width. Isn't 2-3% EXTREMELY low, especially for cranking?

It is throwing 2 codes...Coolant temp sensor circuit and a MAF code.

Checked the CAS and it is getting power.

[SuperHatch]

The main reason I suspect lack of fuel is that I have a wideband O2 setup installed, which normally sits at 22.2 with the engine off. While cranking, it only drops to 16 or 17, while I'd suspect it to be MUCH richer when starting than 16:1.

Just as an FYI. A wideband will read lean whenever a missfire is present, weather from a lean mixture (no fuel) or from no spark. The reason for this is that wideband O2 sensors read the oxygen content of the exhaust to determine the AFRs. When there is a missfire, there will be an over abundance of O2 in the exhaust.

This can actually be seen on the dyno as well. Generally a misfire will cause the torque plot to become jagged, and if this coincides with an abnormally lean condition on the UEGO, you can almost guarantee it is a misfire. This is much easier to see when the UEGO is mounted in the exhaust system nearer to the engine than a tailpipe sniffer. The tailpipe O2 sensors are notorious for reading about 0.5 points leaner than the car actually is already, as well as having a significant delay when compared to what is actually happening in the engine.

I apologize for the rambling. Just wanted to let you know that your lean O2 reading would still occur if you were getting the correct amount of fuel but had no spark, incomplete spark, a spark at the wrong time, or any other form of misfire.

[elwesso]

I posted in your other thread and outside of it being a wiring issue...

you can pull the CAS off and spin it and see if the injectors are firing. Thats the easiest way...

The fuel in for the fuel rail is the one in the front, closest to the oil filler cap. That should be the pressure line coming from the tank. The back one is the return line.

Just for grins, what are you fuel pressure readings at the rail?

[Carl H]

its been a while since i pinned out the vh diagrams but isnt there a power wire for the injectors?perhaps you left this out of your wiring.

[tmorgan4]

Superhatch - You're not rambling on, that's good information to hear. It does make perfect sense that the oxygen isn't going to be depleted if it's not firing.

What would be the easiest way to check that I'm firing at ALL 8 cylinders? The only cylinder I checked is #1. Can I probe one of the wires going into the connector on each spark plug coil and get a reading? The coils are NOT easy to remove on the passenger side, but it can be done with it in the car.

Elwesso - Good thinking on just spinning the CAS. It appears that the injectors are firing from the Consult readings, but this will be a good way to check.

Carl H - There is a power wire for the injectors. There is battery voltage at both of the pins going in to the injector wiring harness.

Things that still seem odd:2-3% injector duty cycle reading while crankingThe injector harness is grounded itself (grounded while unplugged from main harness) on the third pin (supposed to be a ground from the main wiring harness, I thought) of the square plug that connects injector harness to the main harness.

Thanks for everyones help.

[tmorgan4]

Just for grins, what are you fuel pressure readings at the rail?

I haven't tested it with a gauge, and maybe this is a place to start. I know there was a good amount of pressure built up in that pressure line when I wanted to take it off as I let it mist fuel for at least a minute.

[craigztoyz]

You can go to AutoZone and borrow their Noid Lights, I have a set, and use them all the time, you can buy a set of the 4 different types, at Harbor Freight for like 30. You put th elight in the injector harness, and it lights up when it gets the signal to open the injector. You could pull the plugs, attatch the coil to the plug, attatch a jumpercable to the ground, and the other end of it to the plugs threads, if it sparks, you have that off the list, pull 1 plug, attatch each coil, at their location. a lot of work, but deductive logic works.

[tmorgan4]

Thanks to everyone on this board for helping me out. I managed to get it to fire up tonight via the use of starter fluid. This confirms the suspicion that the fuel system was the problem. I pulled the CAS out as suggested and each injector clicks as you spin it. Either I didn't route the fuel lines to/from the regulator and damper correctly or there's not enough fuel getting into the engine.

Last but not least....

http://www.youtube.com/watch?v=EweM82AytbA
Modified by tmorgan4 at 10:32 PM 2/25/2008

[Carl H]

cool, glad its something as simple as fuel line routing...it happens to the best of us man.

[craigztoyz]

AH nice sound on that clip, running!

We need to hav more VH clips on you tube. as soon as I can add to them I will.

Cant wait to see a video of it in action.Do you think you had the lines on backwards, or what do you think it really was? The lil things are always the p.i.t.a.(pain in the a$$)

[tmorgan4]

When I originally planned to start it up, I had a video running with it mic'd up and all. I'll have to get a better clip with some high quality sound once I get it running the way it's supposed to.

To be honest, I'm STUMPED right now as to why it's not getting fuel. I tried reversing the pressure/return lines before Wes chimed in with a definite answer as to which is which, and neither one worked.

The pump seems to be pushing a good amount of fuel. There was lots of pressure built up in the pressure line when I removed it. I need to test the pressure before it enters the engine but I couldn't find a suitable tester. Might have to rig one up.

I think I'm going to try and pull the short line on the front of the engine that connects the two fuel rails to see if fuel is flowing there. I spent a lot of time researching diagrams and what not when I hooked up the pressure regulator and damper but I could still have messed something up.

This is the FIRST engine project I have ever done aside from MINOR bolt ons...like an intake and exhaust. It's satisfying to hear it run since I put the majority of the engine together myself. Paid a shop to do the short block and rebuild the heads. Being 18 it's been a huge learning experience and I haven't managed to mess up too many things in the process.

[Carl H]

a possiblity could be a damaged fpr or a bad pump...ive seen both go bad from not only age but the fpr from hooking lines up wrong.fuel pumps are positive displacement pumps, that means they need resistance to build pressure which the fpr gives.

[T45]

Hell yeah Tyler!!! That ***** if ****ing bad to the bone dude!!!

As for the fuel lines, if you're using the hard lines that exit on the pass side it's the one towards the front of the engine that's supply and the one near the firewall is return. I know you're not stupud but make sure your return line isn't blocked.

Also make sure you have the supply going to the passenger side rail first, then to the drivers side via the hose connecting the rails in the front of the engine, then back to the return line at the end of the drivers side rail after the regulator. Simple as that. Maybe your regulator is stuck? Need gauge.

**** that. NEED ROCKS AND MUD!!!

[tmorgan4]

Thanks Ben!

I'm talking to Wes right now and he advised me to pull off the return line, turn the pump on and ideally fuel should be pouring out. The more I think about it, the more it seems that something is plugged/clogged in the fuel circuit between the inlet and outlet hard lines.

I just found this picture (and a few things have changed including hooking up heater hoses and IACV) but as far as I can see, everything seems to be hooked up right. If you see anything obviously wrong...please let me know. (Sorry 56K guys, easier to see when it's large)

[craigztoyz]

Which fuel pump are you using?????I ask becasue if it does not have enough PSI, then it will not run. I am not sure though how much psi the VH needs.

I don't think though that that is the problem, but hey, never know. Also you can put an inline fuel filter, the clear style in between the input, and return lines, to see if it is flowing, and how well. Cheap trick for testing, but dont drive it that way, too much psi for those filters,

[tmorgan4]

I've still got the stock Pathfinder fuel pump with 120k on it, but it still seems to be working OK. There was a lot of fuel right at in the inlet to the engine so I'm sure it's getting fuel there. It just seems like it's not flowing through properly. Even after cranking the engine over for a while there's NO smell of gas.

I also have a Walbro 255 pump that needs to go in before I rev it up, but I figured the Pathfinder pump would get it started. Going to check for obvious clogs tonight. Thanks everyone.

[SuperHatch]

Honestly, it's hard from your image to tell if you've got it right for sure... but he's what I got out of the FSM...



The FPR is on the left in your picture, the line coming out of it goes to the fuel tank via the return line.

The Damper is on the right. The top port goes to the fuel rail as you have it. The bottom port connects to the filter via the fuel feed line.

[craigztoyz]

If it is going to be a direct swap, do the pump, you already have it, may as well do it now, just to know that pressure is not the problem.

Is there anything coming through the return line?

Pull the coil fuse, and then crank it, try to flood it, just for 5 seconds, it will tell you if you are getting gas, by the smell of the pipe.

[tmorgan4]

Well I'm happy to report back that I've found the problem. After getting sprayed in the face with a quarter gallon of gas and pulling the plenum back off a 3rd time, the fuel pressure regulator is plugged.

I also discovered that I must have mixed up the connections when I hooked up the hardlines for the inlet and outlet since mine were reversed. I have the hardline furthest back towards the firewall as the inlet, as it feeds directly into the damper. It looks correct and I don't see how it it should be hooked up the other way...no biggie though as long as I know which is which though.

Now I'm off to try and find a replacement regulator before the weekend. Thanks guys.

[SuperHatch]

Well I'm happy to report back that I've found the problem. After getting sprayed in the face with a quarter gallon of gas and pulling the plenum back off a 3rd time, the fuel pressure regulator is plugged.

I also discovered that I must have mixed up the connections when I hooked up the hardlines for the inlet and outlet since mine were reversed. I have the hardline furthest back towards the firewall as the inlet, as it feeds directly into the damper. It looks correct and I don't see how it it should be hooked up the other way...no biggie though as long as I know which is which though.

Now I'm off to try and find a replacement regulator before the weekend. Thanks guys.

I have a stock FPR that I would send to you for free, but you wouldn't have it by the weekend...

[tmorgan4]

I have a stock FPR that I would send to you for free, but you wouldn't have it by the weekend...

Appreciate the offer Steve, but no need. I went to the race shop across the street and after looking through all their crap, it turns out an RX7 (no idea what year) had an almost identical FPR. It's installed now and the fuel system is working!

It finally idles on it's own now, with the MAF unplugged. It's a high idle, like 1990 RPM. If the MAF is plugged in it won't hold an idle at all and will actually die on me. I'm assuming this is a sign of a bad MAF, especially considering that when I bought it the guy was unsure of whether it was good or not.

I've got one other small leak that I'm trying to track down and I can't find it. One of the power steering hoses with a cloth like wrap on it is soaked in oil everytime I start it, but I can't find where it's coming from. Can't even tell if it's PS or engine oil.

Slowly getting all the issues worked out. I guess it just takes time. Hope it's worth it in the end!

[SuperHatch]

It finally idles on it's own now, with the MAF unplugged. It's a high idle, like 1990 RPM. If the MAF is plugged in it won't hold an idle at all and will actually die on me. I'm assuming this is a sign of a bad MAF, especially considering that when I bought it the guy was unsure of whether it was good or not.

Do you have any leaks between the MAFS and the throttle body? I was thinking that could be the cause of the low duty cycles while cranking.

[Carl H]

if it idles with the maf unplugged then dies with it in the maf is bad or the wiring is bad...2k idle sounds about right since the tach is calibrated for a v6 and not a v8...

[tmorgan4]

Do you have any leaks between the MAFS and the throttle body? I was thinking that could be the cause of the low duty cycles while cranking.

The stock tube was too long and pushed the filter out over the fender so I've got the MAF duct taped to the TB. It's on there pretty securely and I don't *think* it has any leaks, but it's a possibility. It could also be because I don't have the hose that goes to the IACV hooked into the intake and it's taking in free air that isn't metered which could screw some things up. I guess I should get a new shorter intake tube and hook that line up before spending a bunch of money on a new MAF.

The 2k is idle is an actual 2k not per the tach. The tach read more like 3k, but I bought a timing light with an RPM gauge on it and just left it hooked up to the #1 plug.