Ok, here we go
So I swapped the engine in my 94 Trans Am.

What I have is cammed 96 LT1, Comp Cams Ultra Pro Magnum 1.6 rockers, forged pistons, crankshaft and rods, GP LT1 heads ported by Lloyd Elliot, 2.02/1.60 valves,205 cc intake port, flow about 275/190 CFM, - Injectors SIEMENS DEKA IV 60LB 60 LB, 58mm Throttle Body plus Vortech Supercharger V-1 believe to be S-Trim.
Everything is wired up now.

I can crank the engine but it won’t start. Initially there was no sign of firing at all. At the moment after trying many, many times it seems like I can hear something, probably one cylinder trying to start but not getting there.

I have checked the spark and took off the spark plug and I can see the spark. Fuel pressure seems to be OK ( I haven’t checked Psi however when I press the valve fuel is is spraying out through the valve). When I took off the spark plug it was wet.

Coil – I swapped 2 different coils with the same results. Spark is coming out from the coil.

I tried with fluid started through TB and no change in engine behavior.

At the moment I’m trying to check the engine compression. I bought the test kit but it seems to be not working… I cranked the engine many times and hasn't moved at all. I’m hoping it’s the tester as even with low compression I think I should see something. Correct me if I’m wrong.

As per:
http://shbox.com/1/4th_gen_tech2.html#opti_test
I measured everything and that’s what I’ve got:
ICM Harness
A = ~10vdc-12vdc (or your system voltage) CORRECT

B = 1vac-4vac while cranking NOT SURE IF I’M USING THE METER IN A RIGHT WAY AS I’M NOT ELECTRICIAN AT ALL. MY METER WAS ON AC VOLTAGE (I HAVE 2 OPTIONS 200 and 750). DURING CRANKING I HAD 0 AND 1.

C = ~ 50 ohms or less with key ON ..... ~ 0 ohms to ground with key OFF MY METER WAS SET UP ON 2000 SETTING AND IT WAS SHOWING AROUND 300 SO I PRESUME THIS READ AS 30 ohms, SOMETHING NOT RIGHT IN HERE

D = ~10vdc-12vdc (or your system voltage-might be slightly less than reading at "A") ALL CORRECT

At the end of the optispark harness (disconnected from the opti) with the key ON, you should see:

Optispark Harness

A = ~5vdc CORRECT
B = ~5vdc CORRECT
C = ~12vdc (or your system voltage) CORRECT
D = ~60 ohms with key ON ..... ~0 - 0.2 ohms ground with key OFF MY METER WAS SET UP ON 2000 SETTING AND IT WAS SHOWING AROUND 600 SO I PRESUME THIS READ AS 60 ohms AND SHOULD BE CORRECT THEN.

At the moment I’m worried about the compression and OPTI. I’m hoping compression is showing as ZERo, meter not moving because it’s a cheap one and will be probably faulty… Hope so…

What else should I test before getting the new opti and spending most night changing it?

PCM is still stock. Injectors too big and it won't fire up?
I thought the best idea will be to start it on stock PCM and then reprogram it once I now it does start..

Any suggestions will be much appreciated


Thanks

 

Get a good reading on compression before you go any further. It sound's like your valve timing is off. If you have another car to hook your compression teaser gauge up to to check your gauge you should do it. If the other car reads anything the problem is not the gauge.

If you are getting fuel, and spark, the next logical problem, to me, is compression.

Also, is your ECM tuned for the Supercharger?

 

You need to put a guage on the rail to see exactly what the FP is. Low FP can cause starting issues. 'spraying' is not a measurement you can use for troubleshooting.

 

I'm sorry I missed the part where you said you swapped the pcm as well..... Just making sure you did do that,.Right?

 

did you recheck your valve adjustment? may be a little to tight and holding the valves open just enough that it can't build compression. I think with those injectors and a stock tune it would dump a ton of fuel into it maybe flooding it instantly? just a guess on that though.
I would suggest a mail order tune to get a base with such a modified setup then tweak it from there.

 

+1 to getting a good compression reading. Do not go any further till you verified you have compression

 

Hi guys,
thanks for input.
PCM should be fine as this is the stock one from the car so no VATS problems, same behaviour on the other one without the VATS.

In terms of compression I have stepped big headers so I managed to check the compression on only 1 cylinder. It is showing around 115 - 120 PSI.
I know it's not great however maybe it's because of the set up I Have?

I will check the rest of cylinders over the weekend.

It is:
Comp Cams #07-306-8 Camshaft Extreme Energy, Hydraulic Roller Tappet, Advertised Duration 290/307, Lift .510/.540,

Comp Cams Ultra Pro Magnum 1.6 7/16"

- Forged lightweight pistons SpeedPro LW2256F .030
Higher compression, longer life.
These Power Forged pistons from Speed-Pro are designed to fit tight, thanks to a special aluminum alloy that doesn't expand as much as other alloys. They'll provide the stability and ring control you need, plus the strength you want. Speed-Pro pistons also feature ribbed skirts for better oil retention, and even included new wrist pins!
idle to 7000+rpm Good for street or race/nitrous to150 shot
1.563 compression distance
Approx. Compression (@.030"):
w/58cc heads 10.40:1
w/64cc heads 9.72:1

- GP LT1 heads ported by Lloyd Elliot
LT1 LE2 stage
2.02/1.60 valves
Patriot Gold Extreme springs (155 lbs seat and 400 lbs open)
Steel retainers and locks
205 cc intake port
flow about 275/190 CFM

Numbers in attachment

I need to mailorder new pcm settings anyway.

Any help much appreciated, I'm not a mechanic
Just trying to learn how to make it right.

Still need to check fuel pressure.
Thanks

 

Forgot to mention battery wasn't fully charged but it was cranking quite well for a while then battery went low. Got new battery but need to rework terminals for standard ones so that will be done towards Thursday / Friday.

 

Are you trying to start the motor with 60lb injectors on a stock tune, If so, Why? or did you get this motor with all of the mods already done

 

It is on stock tune I'm afraid, before reprogramming the PCM i just wanted to make sure I can actually start it at all... I had a feeling too big injectors will stop me... Ohhh dear... Seems like it's still a long way to get it running... Hope I can find what's wrong... and hope no need to rebuild the engine.

Engine had maybe 10k on it and heads were refreshed recently.

 

If you are on the stock tune with those injectors, you are feeding over 240% more fuel than you need. It's dumping fuel into the engine. Get that tune done. Or to see if it'll idle drop your stock ones back in. They won't give you power with your set up, but it should at least idle and rev to 2K.

 

[QUOTE=PaulV8terror;18294945] When I took off the spark plug it was wet.



60lb injectors + Stock Tune = flooding, You need to get the IFR changed before you ever try to start it up..

 

If you floor it while cranking it, does it start? this should cut fuel delivery so if you are flooding it, the car should start

 

I remember starting mine for the first time before I adjusted the injector flow rate and it was insanely rich. That was with 36lb injectors. It was burning my eyes rich.

I'm not sure that would even work, it may sputter then stall immediately. Cause when it does start it'll flow fuel again and be way to rich.

 

OK, so plan is to get the working battery connected and send all data to lt1pcmtuning.com and hopefully I will have the PCM initially tuned by the weekend

Will keep you posted guys.

 

Yeah, but at least you'll know its a fuel issue


Good call on the tune! let us know how it goes

 

Mail order submitted with J. Solomon at LT1pcmtuning

Hope to have it back by Friday so I can try to start it on the weekend

 

Let us know if it fixes it. It should...

 

Happy days

Engine is running, thanks everyone for help.

Still few things has to be done but at least I know it does work.

At the moment I can't leave it on idle as the revs are going too low and it stops.

Mail tune very good so far, got lots of info from lt1pcmtuning.com altogether with the tune.

I'm making a list of "things to do" there is a still chance I'll make it to the dragstrip this year

Video from today below:

 

[QUOTE=PaulV8terror;18330462]
At the moment I can't leave it on idle as the revs are going too low and it stops.

QUOTE]

you need to measure your IAC counts. I suspect they are pegged at 160

if so you need to do the "drill mod" but don't do that unless you scan for IAC counts first. Do a search for procedure as aftermarket TB's on camed cars often have low idle issues.