FireInMe17

Alright guys, I need serious help with my 1990 Camaro. I am losing my mind.

Short story, car was a V6, now a V8. Everything put in the car is factory equipment for engine and vehicle management. Running stock harness, stock computer, just have a custom memcal for the car. Nothing aftermarket in that department besides the tune from Scott Hansen.

Car is nearly 100% brand new.

Completely new ignition system
-Spark plugs
-Wires
-ignition coil
-ignition module
-distributor
-cap/rotor

Completely new fuel system
-lines
-filter
-pump
-relay
-pressure regulator
-injectors

Completely new sensors, I have replaced them all

Car has no codes with scan tool

All connections are good, grounds are good, everything has been tested and meets service manual specs.

Car will still not run.

The car will start right up and run, but only for about 10 seconds, then with no warning, shuts off. Try to crank again and it will not start. Wait about 30 seconds and repeat cycle.

I don't know what else to check on the car. I've been working on it for nearly 8 months now and I've replaced everything. The engine is new, trans is new, management systems parts are new. I'm stumped.

Only thing I can figure is that I need to talk to someone that has a lot of knowledge of these cars. I'm past the point of general vehicle knowledge at this point. On paper the car should run, what am I missing?!

Really hoping someone can help me out and shed some light on this. Its eating me alive...

FireInMe17

My number is 5704471366 if anyone wants to text me. I need ideas. I've checked everything I can think of.

thtanner

iTrader: (1)

Did you have Scott remove VATS from the tune?

Security light staying lit on the dash?

FireInMe17

Vats is disabled and no codes present for a vats problem.

LiquidBlue

If you really feel you have exhausted the easy options, I'd try putting a CAN bus analyzer on it and see what comes up.

bk2life

what is the fuel system pressure? starts but then dies, is the oil pressure switch cutting out the power to the pump?

have you tried straight battery power (jumpin fuel pump relay) to see if that helps?

FireInMe17

Everything has power and I've tested everything electrical that tells the computer to run the engine. All the sensors are new. All the relays are new. It has good fuel pressure, primes to 50psi and stays around there for the whole 10 seconds that it does run. The fuel pressure regulator is new. Brand new Bosch injectors and I even got a tester and tested them and they're good. Replaced the distributor because I found out a few months ago that the pick up coil was bad. All my grounds are secured and tight, vats is disabled and the computer gives me no codes. Valves are adjusted correctly, timing isn't perfect but close enough to run. I don't know what else to check.

bk2life

when it starts then dies, when it wont restart have you tried to spray some carb cleaner or something in the intake to see if it will 'run' off the spray? Showing it is fuel related?

Orr89RocZ

iTrader: (20)

What do plugs look like? Sounds like it may be dying early from lack of fuel? When it dies does it restart again?

LiquidBlue

can bus analyzer different from dummy bus reader. you will need to learn the codes as they pass and understand the sequence that should be there vs a bad sequence.

FireInMe17

Plugs are new, good last time I checked them. Have tried different AC Delco's in it with the same results. It will only spit and sputter with ether. But always give it about 30 seconds and it will start right back up like there's nothing wrong, then die again.

Vanilla Ice

Sounds like a fueling calibration error. The car doesn't start to calculate off the injector data until after startup.

FireInMe17

Could it be something wrong with the tank not venting properly? I have two separate tunes for the car, and the other one doesn't work with it either.

Orr89RocZ

iTrader: (20)

No not on a fresh start up. If fuel pressure doesnt drop while running then its not the tank or fuel pump

FireInMe17

Could it be something heating up that's not supposed to be and losing power?

Orr89RocZ

iTrader: (20)

Its not running long enough to develop any heat is it?

Plugs ..i was asking for info on what the burn looks like on them. Is there any color or sign of how rich or lean it is?

FireInMe17

Only about 10 seconds at a time, runs the longest on initial start up.

FireInMe17

https://m.youtube.com/watch?v=48vTxa...ature=youtu.be

This is just now. Video is still processing.

FireInMe17

Is there anyone in my area?

thtanner

iTrader: (1)

If you could find someone with a spare ECM to try that would be kinda nice... Seem to be running out of options

Vanilla Ice

I never saw an answer to the starter fluid question. Does it run on it?

FireInMe17

Only sputters. $250 cash to anyone who wants to come and get it running.

FireInMe17

I've got two computers, neither work, neither do either of the tunes that worked before.

Vanilla Ice

So if fueling sputters that means with fuel introduced there's a change right?

FireInMe17

The same result can be achieved my tapping the gas as I did in the video. That video was right after it started and quit again. I've tested the injectors, they're new and they're good. Pressure is good and holds to prime and in the green when running. Regulator is new and obviously holds good pressure.

Vanilla Ice

Is the only one memcal being used?

FireInMe17

Tried them both. And both computers. One memcal has vats disabled, one does not. But the vats system is intact, and key remains the same.

Vanilla Ice

Sounds funny but did you double check the injectors are connected to the correct point? batch fire may work shortly but then skip and cause a stall.

FireInMe17

How could they be connected any other way?

FireInMe17

They're circuits 467 and 468 if memory serves?

Vanilla Ice

I suppose I'm not thinking clearly. Batch fire should also negate what I was thinking.

FireInMe17

Maybe not enough heat sink compound on the ignition module is causing it to hear up and **** the car off and only when it cools back down it will start again?

Vanilla Ice

How about the knock sensor?

FireInMe17

Brand new...

Vanilla Ice

The parts you listed as replaced, were they replaced to try to fix the problem or were they new to begin with? It's possible there is a faulty piece in there.

FireInMe17

Wanted new ones anyways, the issues I was having drove me to buy them new sooner though.

Orr89RocZ

iTrader: (20)

I am several hrs away nearer pittsburgh. Possibly could take a look at the tune and see what is in it and maybe even try one of my own

FireInMe17

I'm going to readjust my valves and put more dielectric grease on the ignition module. Guy at work said if there isn't enough between they module and distributor it could cause a problem.

Raysir

If there was a problem with the valves it wouldn't run to start with. Wasting your time there. Good luck on more grease. You say you tested the injectors? How and what reading?
I've been fighting a hot start , no start for months, tried the hi flow pump no help. My truck is a total rebuild restomod. All new engine and all electrical. Converted from 85 MAF to 92 MAP for looks. Noid lights and spark showed great. WELL, I'm a 30 yr. ASE Master Tech with the conclusion "the injectors are new only 2300 miles" BAD diagnosis on my part. I was look'n at this site and bk2life on this site said something of spraying fuel.(a different thread) WELL it worked truck started hot and the injectors pick up...runs a little rough but livable. I think from the extra voltage of the charging system it caught up. My injectors read all the same at 16.2 ohms (spec is 15-16.5 ohms) when cold and it started great. Get it to operating temp about 200, shut it down and wait 10 minutes, it would sound like your video and no start til completely cold. The injectors hot read 6.2 -8 ohms on 4 of them. 17.2 ohms on the other 4. They shouldn't vary cold to hot more than 1 ohm. Don't use re-mans. I had GB reman injectors in it from Rock auto, JUNK. Bought Summit new and they read the same hot or cold at their spec 12.4 which they tell you. Hope this helps , the spray fuel helped me. THANKS bk2life

Raysir

If there was a problem with the valves it wouldn't run to start with. Wasting your time there. Good luck on more grease. You say you tested the injectors? How and what reading?
I've been fighting a hot start , no start for months, tried the hi flow pump no help. My truck is a total rebuild restomod. All new engine and all electrical. Converted from 85 MAF to 92 MAP for looks. Noid lights and spark showed great. WELL, I'm a 30 yr. ASE Master Tech with the conclusion "the injectors are new only 2300 miles" BAD diagnosis on my part. I was look'n at this site and bd12 on this site said something of spraying fuel. WELL it worked truck started hot and the injectors pick up...runs a little rough but livable. I think from the extra voltage of the charging system it caught up. My injectors read all the same at 16.2 ohms (spec is 15-16.5 ohms) when cold and it started great. Get it to operating temp about 200, shut it down and wait 10 minutes, it would sound like your video and no start til completely cold. The injectors hot read 6.2 -8 ohms on 4 of them. 17.2 ohms on the other 4. They shouldn't vary cold to hot more than 1 ohm. Don't use re-mans. I had GB reman injectors in it from Rock auto, JUNK. Bought Summit new and they read the same hot or cold at their spec 12.4 which they tell you. Hope this helps , the spray fuel helped me.

FireInMe17

How about these then?

https://m.summitracing.com/parts/acc-150821

FireInMe17

Reset the timing yesterday, adjusted the valves, tested the injectors with the tester I got, they all worked. Still no luck.

bk2life

have some one spray a continuous stream of carb cleaner or starting fluid in the intake tube while you are cranking it. I have an LS swap I'm doing that the injectors are junk/plugged from sitting for a few years, that being said, I can make the engine run by spraying the fluid into it. What this does is positively show A, the engine runs, B the ignition is working, C eliminates the guesswork of the fuel system. which D proves there is no fuel getting in engine. ---if you do this, it will tell you all of the work you have done (valves/ignition grease/computer etc is working)

it takes less then a minute to do, and will give you undeniable answers to what you don't know.

do it, let us know. and then go from there.

--recap, spray a continuous stream of carb cleaner/brake cleaner/starting fluid into intake tube while someone cranks the engine over.
--if it runs, albeit not the best, but will run at apprx 1500/1800 rpms
--then you know without a doubt it is fuel related.

if it doesn't run, then you know its ignition, computer related.

Raysir

[QUOTE=FireInMe17;6065229] It has good fuel pressure, primes to 50psi and stays around there for the whole 10 seconds that it does run. The fuel pressure regulator is new. Brand new Bosch injectors and I even got a tester and tested them and they're good.

Your fuel pressure should still hold even after it quits for quite awhile. Should be at 41 psi at idle and hold steady. Sounds like it drops really fast when the car shuts down or the pressure gets used up as the pump shuts down and then quits. Have you run power directly to the pump side of the relay? It should run even with the car off. Also, you say you tested the injectors. What kind of tester? Using a noid light just shows that they are getting power from the computer. I had noid and mine were all out of specs on ohms and wouldn't start hot. Are you using a digital volt/ohm meter across the injector spades? Mine were re manufactured new injectors from Rock Auto/ GB Remanufacturing...JUNK. Less than 2K miles but it never ran right from the start. Disconnect the injector wires and stock injectors should all read 15-16.5 ohms hot or cold.

Raysir

This tip got me on the right track but I used a spray bottle with gasoline into the air intake. Then it would even start after hot soak with a few sprays into the PCV valve. It was junk injectors from day one 'new' reman injectors. I was fighting this for 6 months when hot...started right up after the tow truck got it home. I'd use gas rather than start fluid...they warn you can blow head gaskets with it since it really knocks.

FireInMe17

I don't know what the deal is with my multimeters that I have, both of them don't read resistance on anything.

Vanilla Ice

This tip was given twice, long ago. Hopefully you figure it out this time.

FireInMe17

Yeah and it didn't work. And then when I check the ignition system, it's working too, get great voltage from it. Fuel system gives good pressure and I've never seen it drop below the minimum 37psi that the engine needs to ide. No codes in the computer, vats system doesn't seem to be giving any issues about the engine swap.

The reason I started this thread was because I wanted technical information about how the management systems in the computer work and what the checks the computer is doing because I'm convinced the problem had something to do with something not checking out right in the computer. Whether that be with the tune, the wiring, a short somewhere causing it not to read something, a loss of data from a sensor, or something along those lines. Something to be said about the oil pressure switch or something wrong with a sensor voltage. The problem is beyond does it have spark or fuel, those are both there.

someone972

iTrader: (2)

Have you considered buying or building an ALDL cable to datalog with TunerPro RT? Then you should be able to at least know what the computer is seeing. I'm not an expert on these engines yet, but I'm usually available on Skype if you want to just shoot ideas back and forth. You might be able to find me by searching my username otherwise I can send you the contact info if you are interested. Sorry to hear it's giving you such a hard time .

89Z

I read this thread kind of quickly, but it appears as though you still don't know whether you are lacking fuel or spark when it shuts off. So, try this. It's fast and free. Pull a connector off an injector and connect the noid light. Pull a spark plug wire off and connect a known good spark plug. Start it up and then as soon as it dies, have an assistant crank the starter and observe whether the injector isn't operating via the noid light or you aren't getting spark by observing the plug. Please report back. Sure sounds like computer (ECM) or VATS related.