420A Turbo won't start after build

[glowryder]

true, hbut only to a certain degree...its ver possible that its far enuff out that it wont start, or it will fire only every numver of revs.. since you ###### have oem cam gears,your timing needs to be right on...

 

[rstare]

I was off two teeth and it ran....
The CPS and CAS sensor will compensate ignition timing in order to keep it running.
I datalogged the timing advanced and it was jumping all over the place, it eventually leveled out around 5* but it was still missing bad.

 

[rstare]

I just realized that you posted that other thread about your fuel setup.
What is your idle fuel pressure?
Have you looked at your plugs?
Do you have a wideband?
You can run too rich and cause your car not to run at all.
I think you said you had 40psi of fuel pressure.
If this is right; pull your plugs... they will be black.
Put in your stock injectors and the stock FPR.

 

[PCD_RS]

Lets move the fuel discussion to where I poasted for the fuel stuff. I think I'm slowly figuring out what is wrong with my car. Thanks rstare for all the help!

 

[PCD_RS]

Ok so I installed the new CAS and it still won't start. I was 110% certain that my timing is right on. I had to get a special connector for the new CAS; you think I soldered the wires in wrong? I figured the dar wires would go together and the two solid colored wires would go together and the striped wires would go together. The connector didn't have any description to what wire was what. I got it at autozone: item#445 connector. You can find it at their website and under search type in 445 and it will show a list of items under that number. I can't copy paste the link since I'm on here using my cell phone, my bad guys.

 

[PCD_RS]

Sorry to resurect this thread, guys, but, my car still won't start!! I've redone the timing countless times. Replaced the CAS and the CPS sensors. Re-checked compression, spark, and fuel over and over again. And all the engine does is... TURN!! Nothing more.

Could my injector timing be off?? If it could be that problem how do I go about doing that? I've never messed with my injector timing or anything of the sort.

When I try start it sometimes I get a backfire in the exhaust. So I know something is getting ignited(sp). But I don't hear it sparking/combusting at all. I am all out of ideas on what to do, guys

EDIT: I'll take pictures of my engine and the timing marks and everything tomorrow so you guys can get an idea of what it all looks like.

 

[rstare]

2GNT.com - PROBLEMS
Try looking through these.
Specifically this one,
Team 2GNT Forum - Viewing topic #87416 - Car Wont Start, No Spark, No Power To Coil....Another Dumb Question

 

[96TurboGS]

Some things to check would be the asd relay (in ohms or listen for the click) and the coil pack. A lot of times the coil pack can be within specs and still fail, but that rarely happens (it happened to me). Check the injectors with an ohm meter it should be around 12-14k ohms I believe. If you have replaced everything and reset the ecu then I would look at the ecu for failure. Do you have any new codes? Have you verified you had spark by taking the wires out of the well? Have you measured the primary and secondary windings of the coil? Is the coil getting power? If your plugs are fouled it might be wise to change them to get a better spark.

 

[PCD_RS]

Some things to check would be the asd relay (in ohms or listen for the click) and the coil pack. A lot of times the coil pack can be within specs and still fail, but that rarely happens (it happened to me). Check the injectors with an ohm meter it should be around 12-14k ohms I believe. If you have replaced everything and reset the ecu then I would look at the ecu for failure. Do you have any new codes? Have you verified you had spark by taking the wires out of the well? Have you measured the primary and secondary windings of the coil? Is the coil getting power? If your plugs are fouled it might be wise to change them to get a better spark.

I got an engine code 11. Looked it up and it could be no signal from the CAS to the PCM. Timing belt jumped 1 tooth or more. Or it has intermittent loss of signal from the CAS or CPS to the PCM.

I've got brand new NGK plugs and a brand new coil. I understand that if the CAS or CPS isn't doing its job that it wouldn't send a signal to the coil to the plugs. Is that correct?

 

[96TurboGS]

Crank shaft Position Sensor (what I call it) is what you need start the engine. That code 11 is your problem; you should see around 5 volts while cranking. Also check both connectors for oil, as it will mess with your signal. Measure each signal wire (CPS + CAS) for voltages while cranking and tell us what you get. Timing would be something to look into also. Invest in a datalogger. Get rid of the code 11 before looking into anything else. Check wires for damages, try to reset your ecu... take the cables off have 4 beers then come back to it. If it doesn't work then rule out the ecu.(last resort tho)

 

[PCD_RS]

Sorry guys I havnt been on in a few days. Thanksgiving and was with family. Anyways! Onto the subject...

Got rid of code 11. Wire broke loose and had to re-solder it. Now problem is no spark. Now from what I think; tried to fire her up and definitely sounded like shw wanted to start, but didn't. Checked if I was gettin spark. No spark. Brand new coil pack branfd new plugs like I stated before. So conclusion: bad wires? Bad connector to coil pack? Bad ground wire to coil or broken wire somewhere to the coil. It only has 3 wires on the connector to the coil so its either ground, signal or power.. that's what I think it boils down to. Let me know what you guys think; if I'm right or wrong or if could potentially be anything else? Thanks guys for all the advice. It is much appreciated!

 

[freshlane]

Pull the DVOM out and check for continuity to ground and check for sensor voltage. Also check continuity from the plug to the ECU. You gotta trace back bro.

 

[PCD_RS]

Ok so I got a zero reading for ground. For signal and power I get zero too... That doesn't sound right does it. One should be 12v right? When I turn the key to the on position? So that means I'm losing power somewhere, correct? I hate electrical stuff, man That's Why I stick with the mechanical side of things

 

[96TurboGS]

Nice to see the code 11 is gone. Have someone turn the key while you have the volt meter and measure the middle pin (red/black) of the coil pack connector. U should see it spike up to 12 then back to 0 (like the fuel pump priming for a second). If you turn the key then go to measure it, you will miss the 12v+. When your cranking you should see a constant 12v+ till you stop cranking. If not it's either your relay or your ecu or your volt meter. I love working on ol skool v8's, but if I had it my way I would add some electronics to it.

 

[PCD_RS]

hoe-kay... So where would my relay be for the coil pack? Or in other words, the ignition relay, correct? I still have yet to test continuity since I need to find a helper still. I'm really hoping my ECU is ok. Are '96's ECU's pretty good? I know the '95's had some issues with theirs dying.

Yea dude, electronics go a long way for cars. But a pain at the same time. Love hate haha

 

[96TurboGS]

It's the 95's and some early year 96's...good thing mine is a late year model. Judging from your engine bay pics you have a late model. My friends had his cut off on him in the middle of the freeway and started back up perfectly. He also had idle problems from time to time. The relays are on the firewall, the ASD should be the one on the left looking at the engine. Get a wire and connect it to the red/black wire (coil pack connector) and have the volt meter hooked up by a long wire and watch your volt meter while you crank. It's the way I've done it for years. People say listen for the click, but I never hear anything.

 

[PCD_RS]

so problem was a blown ASD relay. i wasnt gettin anything when i tested it. thats what sends the signal to the coil pack correct? since i wasnt gettin spark. i hope this is the problem! thanks man!

 

[96TurboGS]

SPDT (Single Pole Double Throw) relay (about 12 bucks) is what you want to look for if you don't want to spend $50+ for a new oem one. Yes it is what sends the 12v to the coil. Remember before you go to buy one take the relay out and test it for the click. Here is the link to test both relays.... Test your fuel pump relay first to hear the click (since its good) then test the asd.

Troubleshooting, Testing and Bypassing SPDT Power Trim Tilt Relays for Boats

 

[PCD_RS]

ok say that after i do the test for the click, and if it does click, what would the problem be then? dead ECU? leaking capacitors in the ECU? there isnt an inline fuse to the coil is there? just wondering

 

[96TurboGS]

Either that (ecu) or your wire to or from the asd is screwed from heat/corrosion and whatnot. The ecu grounds the relay which turns it on providing the 12 to the coil; there is no fuse (that I know of). Have you checked it yet? Only takes 2 secs...our ecu's are pretty rugged, i cant tell you how many times i hit it with a socket wrench causing a big ass spark from the battery terminal.

 

[PCD_RS]

Yea I've checked both relays. The one on the left is the ASD, correct? And the one on the right is the fuel pump relay? Both are working fine they clicked when I tested them. SOOO I'm hoping it is a from heat/corrosion. It would make my life easier!!! 'Cause right now I'm

Well that is good to know that your ECU held up after a huge-ass spark!!

Another question: I was talkin' to a friend and he said that MSD sometimes messes up some cars. Is that true? Just wanted another opinion on it 'cause I ran the MSD when I first started her up after the build then she died.

 

[96TurboGS]

MSD coils should be good, a lot off 2gnters don’t have a problem with it. You must be getting it confused with the MSD DIS-2 (Ignition box). If you heard a back fire from the exhaust or it attempted to start up I would say it’s something in your fuel settings that’s preventing you from starting up....but you said you didn’t see a 12v from the relay are you measuring the voltage correctly?? It’s unlikely it’s the wire unless the EGR ate something up. Measure the red/black wire on the coil pack pin (not the ECU wire) while cranking...you should see the 12v!!!

 

[PCD_RS]

Ok so... I removed my VC and was checking my cams. They're lined up and whatnot with the factory marks on them facing each other (3 o'clock intake and 9 o'clock exhaust). When I rotate the engine, the intake valve opens as expected, BUT the exhaust valve opens right after the intake valve closes. Now from what I saw I would say my piston has no time to compress the air and fuel at all. Again my timing marks are on the money, yet it seems off to me. So something broke or the factory timing marks are way off. What's your guys' input on my diagnoses?

And I have not gotten to test for another 12v on the connector. Left my Multimeter in the lab which is locked on the weekends.

 

[TOONAH]

I have no experience with the 420A, but cut my teeth on four bangers forty years ago.
It sounds like the base timing is 180 degrees off. But through out the entire thread, no one suggested that you should set up a timing light and see if your spark on #1 is occuring
around TDC when you crank it over. You have to take a very logical approach to a no start scenario. What you have been doing is shot gunning it. I know you hate to keep putting new parts in it. You really need an oscilloscope to troubleshoot ignition problems.
You need a wiring diagram. Identify the 12V ignition power wire that supplies the hot side of the coils. If that is present then you put a scope on the input to the "igniter". It is usually the base input of a transistor. The dwell is about 3 ms, also known as the time the primary side of the coil charges up. If there is no pulse, you trace it back to the ECU.
The pulse turns off, the magnetic field in the primary collapses and since the flux collapses around the secondary winding, an electrical potential (ie current) is developed in the secondary. It is usually 25-45 thousand volts! This is enought to arc across the spark electrodes. I am trying to help you by keeping your mind focused on the basic theory, one can proceed in the analysis more logically.

 

[PCD_RS]

Thanks, TOONAH, for all the help. If I had a timing light or osclliscope handy I would hook it right up and check everything right off for the spark in #1 as it reaches TDC, but I don't.

I'm gonna check my timing again and see if it jumped any teeth. Doing this again to make sure it's right. Line everything back up and reset the ECU and handcrank it to check if my camshafts are doing the right thing. Since it all seems backwards to me how the intake closes and the exhaust open right after. That would make no compression and would throw off the crank sensor from the cam sesnor as well I would presume since they go off each others signal. And spark would occur if the timing was correct, right? If it all was off (like in my case with my camshafts) then nothing would happen, and the engine would just turn over and not start, right? Am I way off, or somewhat on the right track with where I'm going?