It is unprotected, yes. It will have to be fixed someday...

I like your point. I wonder if the previous builder (who also tuned the PFC) could have tuned it with the water temp sensor connected wrong? Is it possible? I ran the car 4 years with that tune...

It has a tune in it, but at this point I just want to get this car started. Then I'll have that car retuned.

My only goal right now is to get that car started.

200A fuse didn't blow with the spare FC starter (but I haven't cranked extensively neither).

 

I would throw a stock ecu on to start, or reset the PFC. Any old tune is suspect.

 

Yes. And I don't trust the previous tuner too much. I just unflooded the engine (one more time) and spark plugs are in my hand, I'll wait a few hours before trying it another time.

Meanwhile, I adjusted the TPS this afternoon.

 

...if it's not heavily modified. Plus you get the added benefit of CELs

 

Okay, I just tried to start it now. Unflooded and waited 4 hours, battery charged, spare starter (FC3S) used... 1st crank at 170 RPM for 4 seconds... Nothing. Not a single explosion. 2nd crank for about 7 seconds, 200A fuse blew.

So I know for a fact that the problem is not the starter. There is a short somewhere.

However, where is somewhere? I'm really not sure where to go from there.

 

Do you have any custom accessories or custom wiring? It would be a big amp draw behind that fuse...like maybe the fans coming on high, or a big stereo filling up caps, or a crazy big short.

 

....or the starter

 

Lots of custom accessories, unfortunately. Wideband, water temp gauge, oil pressure gauge, boost gauge, turbo timer, aftermarket radio, battery relocated in the trunk... I'm really scratching my head now.

Starter can be eliminated, I tried a spare starter and nothing changed.

I attached a picture, just in case. I just want to make sure that the positive cable is connected to the right place (we never know...).

Also, this ground has always been carefully zip-tied if I remember correctly. I just want to make sure everything is OK here. Positive cable physically seems to be in good shape, wiring from the battery to the starter seems OK to me so I'm looking at the basics.

 

170rpms is pretty low. Should be 250 on start for a healthy motor. Feel like the battery relocation and starter wiring are in the mix, especially regarding the fuse. It wouldn't be the gauges, but the stereo could be drawing power. Might disconnect to be sure.

But, would try to reset the tune first. Have you checked the injector settings in the pfc? Sorry if I missed it.

 

Post a picture of each screen under the settings tab. Maybe we can see something to help rule out the power fc and the tune completely. After the water temp thing, that should have been it. Your fuse situation is confusing but let's focus on one thing at a time

 

First thanks a lot for your help guys. I really appreciate what you're doing.

I'll disconnect the stereo, it won't hurt. I never posted the injector settings before and I don't quite understand what it says to be honest...

I thought the water temp thing was "dumb and simple", but it just seemed to have worsened the problem, which is weird.

 

 

- IGN split looks a little weird in idle area
- Inj Adjust settings (2 pages) should all be 100% - since they are below 100 now changing these to 100 should only make you run richer
- Idles and rev limit are all high

I don't think these would prevent starting, but I've never played around with these values.

There are a number of PFC settings that can't be seen on the commander. Some of these could prevent starting, but you probably didn't change any of these or load a new map since the car last ran.

If you're blowing a 200 amp fuse I think you focus on that first.

 

The altered PIM voltage is really odd. That's typically a quick hack to test if you need to lean or richen something out. If it was tuned it wasn't tuned properly.

PIM voltage modifies the voltage coming from the MAP sensor to the ECU.

Do you have stock injectors primary and secondary?

I'd be doing an All Data Init on the PFC, those are a lot of weird settings just from a quick look.

BTW, you are a hero for sticking with this .

Dale

 

I agree for the 200A fuse, it is kind of annoying.

Primaries have been cleaned and tested last summer by a reputable shop, I should remember if it was stock or not... I am pretty sure it was.

I can't believe all the help provided by this forum, Viper forum people would have told me to send the car to a shop a long time ago.

All Data Init on the PFC has been done.

I just tried to start the car, it was a bit faster (180 RPM). Blew another 200A fuse. Please note that I quickly cranked before reinitializing the PFC and speed was also 180 RPM.

 

Have you eliminated the starter circuit? If you're blowing a 200A fuse when you try to START the car, that's probably where your short is

 

How is your battery location and starter wiring set up? How is it routed? What sort of wire did you use? Quality, gauge, etc?

Is it possible to un-do it and put it back like stock?

 

I did not eliminate the starter circuit, only the starter itself. I'm thinking the short is there too (but where, I've got no clue).

Relocation has been done 10 years ago, it is not possible to un-do it unfortunately (I don't have the stock parts anymore). Starter wiring hasn't been modified.

I've just unplugged the stereo. Same RPM, it still blew the fuse, but... I heard some explosions. That was the first time it happened since I connected the water temp sensor to the right location. In my opinion, it will start with a higher cranking speed.

Battery seems to be draining too fast, I tried to exchange it at Walmart but they tested it and it still is in brand new condition.

 

You should have 2 major grounds. One to the body, one to the engine. 2ga cable is fine, but do a straight run to each.

That won't fix you short circuit problem though.

 

Sadly!

I thought maybe the "bad" ground cable could have been the reason to my problem...

 

Is that big aftermarket fuse near the battery the one that has been blowing when you crank the engine for a long time? If so, my guess is the starter is the only circuit that can pull that much current multiple times without frying itself. According to the wiring diagram (pg Z-24) there's not a fuse in OEM wiring harness between the starter and the battery so it might draw more than 200A occasionally. The largest fuse in the wiring diagram is the 120 amps main fuse which powers the cooling fans and feeds power to the battery from the alternator (when the engine is running). 200 amps is a lot of current. Most wires on the car are likely to burn up and not even be able to carry 200 amps long enough to trip a fuse. The only exceptions I can think of are the big wires feeding the alternator, headlights and cooling fans.


If you're cranking the engine for more than 10 seconds you are wasting your time anyway. If the engine isn't getting the right amount of air+fuel and a correctly timed spark for the first 10 seconds, running the starter for 10 more seconds is either going to flood it further (if there was too much fuel being injected) or keep spitting the same too-lean mixture out the exhaust ports. My suggestion is use a timing light to confirm there is spark happening near the OEM mark, then remove the intake elbow so you can see the throttle body. Try opening the throttle body and spraying a small amount of starting fluid past the open throttle (with the engine off), then wait a few seconds for it to evaporate and try to start the engine while holding the throttle open about 10%. Don't repeat this too many times, unburnt starting fluid will turn your catalytic converter and muffler into an explosion hazard.


I agree a stock ECU might be worth a try, assuming you have stock injectors and stock MAP sensor. It might not drive well at full throttle but there's a good chance it might start and idle.

 

To track down your short, get an ohm meter and check resistance between the positive cable in your starting circuit and any ground point that should be connected to the ground on your starting circuit. It should read infinite resistance. If it reads 0, there's a definite short. If it's between 0 and infinite, you've got a parasitic draw which is probably why your batter is draining. There's a bunch of on-line videos on chasing down a short

A "bad" ground cable won't create a short, but will diminish your voltage. V=IR, or the more resistance you have = less voltage you are able to produce. It should be upgraded.

I also don't like the unprotected starter solenoid connection. It may not be causing a direct short, but it might possibly arc if it's close enough to a ground point (i.e. the body). If it's arcing, you won't read it in an ohm test

 

The ground cable from the battery - it almost looks like it goes to a bolt in the spare tire well then back to another bolt? Or is it just the picture?

Stock, the ground wire goes from the battery to a bracket bolted to the driver shock tower (the bracket that holds the fuse/relay block) to ground to the body then goes to the bracket on the AC/PS bracket to ground to the engine. Do you have a thick ground wire going from the engine to the body? The engine needs a fat, solid ground for the starter to crank well. That can directly impact cranking speed.

The starter main power wire typically has a rubber boot around it so it can't accidentally short on something. I had an FC back in the day that was missing that, I replaced the starter and after a few days the wire shorted to the starter and that was interesting .

Dale

 

If it were gonna start, I think it should have started even at 170rpms. But, I would re-work that remote battery install. Also agree about checking the spark timing. You got the plug wires and coils double checked? If you mixed up leading and trailing it wouldn't want to run good.

 

Yes, the aftermarket 200A is 1 foot away from the battery. I usually don't crank the engine for more than 10 seconds (usually 5 seconds at a time maximum). I've had that battery setup for 6 years, without any issue (from 2010 to 2016, car hasn't ran since then). Are you saying I could try to bypass the 200A fuse? I'd have my extinguishers nearby... I tried the starting fluid when the water temp sensor was to the wrong location, I'll try it again...

I don't have a stock ECU unfortunately. I've got no clue how to use a timing light. I looked on YouTube and there are videos about it only on piston engines, I searched on here and nothing either...

I have to change that ground cable. They won't believe me at the auto parts store tomorrow when I tell them I want an inch thick cable.

I looked up a few videos on chasing down shorts. When car is off with the battery connected, everything is in good shape. That is all I can say for now...

Starter solenoid connection is now protected, I found a rubber boot from an old starter wiring.

I did not check the resistance between positive cable and any ground point, I will have to do that.

The ground cable goes directly to the bolt that we see, sorry for the confusing picture. I installed a large braided ground wire from UIM to the firewall. Rubber boot has now been installed so we can eliminate that possibility.

I've just checked coil wiring. White connector front trailing, black both leadings, blue rear trailing. I remove the spark plug wires everyday to unflood the engine, I'm not concerned about mixing them up.



Today, I'll be honest I mostly watched the car desperately. First thing in the morning I cranked the engine and it went up to 500 RPM. Then that was it. Explosions mostly happen when I first try after a few days sitting (or overnight like this morning). Right after unflooding the engine, it is always weak and I never hear explosions.

Basic question: are the injectors connected properly (not reversed)? I looked into the FSM but I couldn't find the information...




RECAP


The problem:

1. Engine doesn't start - "fresh" rebuild by myself.
2. Battery relocation: aftermarket 200A fuse keeps blowing after cranking for not so long (never had any problem with that relocation for the 6 years it was installed).
3. Slow cranking RPM, maximum of 180 RPM (only lasts a few seconds, then goes down to 170, 160, 150... And the battery gets low).
4. All 3 problems are most likely related to each other.

Done:

• Car unflooded multiple times.
• Compression tested
• Coil packs tested.
• Spark plug wires tested.
• New spark plugs 4 x BUR9EQP.
• New genuine fuel pump Walbro 450 LPH installed and tested.
• New battery.
• Tow start tried at 15 mph - didn't work.
• NE and G CAS connectors at the correct location.
• Starting fluid tried - a few explosions for a few seconds, then nothing.
• 12V on each injector: success. They click and work properly (I physically saw gas coming out of them).
• Pumped old gas out, pumped new gas in (without 2-stroke oil).
• Map sensor voltage tested and within OEM specs.
• Ground at the PFC tested.
• UIM to firewall ground tested.
• Changed starter (no change whatsoever).
• PFC reinitialized.
• Stereo unplugged.

Homeworks:

1. Buy new ground cable that goes directly to the battery.
2. Spray starting fluid in UIM.
3. Check resistance between positive cable and ground points (starting circuit).
4. Learn how to use a timing light...