I'm trying to sort out a new buildup and can't get it to fire. RUNDOWN: 415 Motown block, AFR 210 heads, Isky 234 @.050 roller cam. Holley Stealth Ram w/ 36/lbs injectors, Holley '160 computer controlled distributor, Jacobs C4 coil, no ignition box. It's right now installed on an engine test stand. I've got good fuel pressure, 12.6 volts, good spark and distributor is set 10° BTDC. SYMPTOMS:What it appears like is it's flooding. A real stong gas smell, black smoke out the pipes if it does fire a few times, and mostly, things go from bad to worse - much like a carbed engine does. A few fires at first, and then nothing until you dry off the plugs. Not until I open the throttle will it start firing and then it's pretty ragged. I've pulled plugs they seem wet... not dripping, but they will leave a spot on a paper towel when you dab the end. I've loaded the 383sbc30 and 383sbc36 maps. In the whole process of starting this engine, I have been leaving the ignition on for extended time while loading maps, checking things, ect.
THEORY:Could the injectors be firing or leaking while the ignition is on but the engine is not running. I feel like I'm doing something stupid 'cause everything else is checking out 'by the book'. Thanks for any tips,
Bill

Bill,
Hopefully Doug will get back to you soon. I just wanted to chime in and say be careful that you dont "wash" the rings with too much fuel. I would wait until you get hold of Doug before trying any more, its not worth damaging the cylinder walls. One quick thing you might try is putting in a fresh set of plugs. Once a new set is fuel washed, they usually cannot be saved. Might not be a bad idea to change the oil also ... cheap insurance.
I am curious to see how you make out as I am planning to use Holleys system if I ever get the 383 done for my Heavy Chevy.

I just recently setup a Holley stealth ram in a 383 Monte Carlo. It has a similar set up 540. Lift cam 110 lobe Sep and some gm performance parts heads. That stealth ram throttle response is unbelievable. This is what you may need to check
First go to your basic engine set up under hardware settings. Make sure that you have the correct ignition type for your distubutor (HEI, etc) map sensor type (which is the brain of this system) speed density. Choose port injection and for load sense, choose speed density. After you do this choose send ecu data. Do this with the power applied to the system.
I would also check the throttle position sensor and map sensor (drawing a vacum on it) at this time also. You can see the values change under the main fuel map menu. Also if you are running open headers for you test set up. Your oxygen sensor will have some incorrect reading because of the leaner conditions from the open pipe.
By the way , make sure you have that map sensor hooked up to a good manifold vacum source, If it doesnt get and good vacum it will have those injectors open up wide open and flood the engine.

Those base maps are okay to get the engine started and to break in the cam. You can add more fuel to the cells while the engine is running to get the best tune. ohh, you will have to "sync" your computers timing with your actual timing by working with the timing light and comparing the timing on the computer and add more timing or subtract timing with the distubutor until you get the same number on you timing light that you have on you timing cell at the rpm that is show on the tach. I hope this will help get it started for you.

Thanks for the info! I'll check the MAP sensor for good vacuum.. I noticed the barbed fitting was not a snug as I would like - I'll add a clamp. I've done all the prelim setups - ignition type, injector type, but I haven't been able to see the MAP reading stay anywhere long enough to trust.
-Bill

Bill, if your reading won't hold a constant value while you are apply a steady vacum. That map sensor may be bad.
I usually use the quick "old school" method. Suck on the vacum line and hold it with my tongue. It may sond funny but it works for a quick check. You can try that out and look under your fuel map and see if the red cell stays in a single block. This will surely verify if that map sensor is bad.

Everett, I've got one of those brake bleeder kits that has a nice vacuum gizmo with a gauge. I'll give it a try tonight to check the map sensor. Thanks!
-Bill

While it may be possible, it's VERY unlikely that the injectors fire while the ignition is on.

How are you sure the dizzy is at 10deg btdc without the engine running to put a timing light on it? Just because you tell the computer that you're at 10deg btdc, doesn't mean you are (sorry if know this, just trying to cover the basics redface.gif )

If you truely are getting good spark... find a cranking fuel table and lower the fuel being shoved into the engine in the first few reference pulses and see if that helps.

Don't load the 383SBC30 if your injectors are bigger than that. It will spit WAY more fuel out than needed. To lean it out You can also try loading a 383 setup with a larger fuel injector IE 383sbc42 or something which will think you have bigger injectors and will lower the pulse width.

IIRC the computer does nothing with the MAP until the engine IS fired.

Twilight,
I set timing with plugs removed and coil and #1 wire only to distro.(had crossreading with all wires hooked up) I've set it to 10deg. BTDC while cranking (no fuel) about as fast as I could think of without running.Also had the bypass pigtail unhooked - per Holley's suggestion) I'll try the bigger injector map - that makes alot of sense!! Thanks!
-Bill

If your timing is that close it should fire.

Check your fuel pressure too but be VERY CAREFULL with that schrader valve. It busts off real easy.

You want a fuel pressure in the neighbor hood of 41-43 psi. Be sure your fuel lines aren't crossed either.

If you have the regulator BEFORE the injectors(or the lines are crossed to create this, your injectors aren't going to get the pressure to spray and it would just dribble.

Twilight,
I've got fuel pressure at about 44psi - I have one of those 1" gauges on the fuel rail (pulled out the little valve) I'm thinking now much more toward a vacuum problem. I checked the MAP sensor and it reads just fine with my vacuum pump thing (brake bleeder - does lots more than brakes!)The two hoses that run from the plenum to the fuel regulator and MAP sensor seem poor fitting, so tomorrow night I'll change those out. I let you know how it goes! Thanks!
-Bill

Bill, I will have to check to see what base map we loaded to get our engine on started. I know we set the timing by the old school way. The rotor pointing at number 1. Once the engine got started up. We turned the distributor until the engine ran smooth about 2500 rpm, just to break in the cam. After that we synch the engine timing with the computer timing. I would suggest of you can get it started with the disturber you have. Use a old HEI distributor and see if it will fire with that. We used the stock one that came with the 87' monte. Going with the basic setup will sometimes help. I know all you want to do is get it running first. That is what we did. Keeps us posted. If you need more details on my set up shoot me a email. everc@nc.rr.com I can send you that map that we currently running.

OK.. this beast is startin' to annoy me!
Got clamps on all the vacuum lines, fresh set o'plugs, and a fairly lean fuel map. At first I tried starting and it was the usual couple pops and then nothing. Then opened throttle while cranking and got it to fire. It's ragged but running - it'll backfire a fair ammount. RPM shows about 1200-1300, MAP is reading about 45-50. Then if I close throttle, it nearly dies. So I crank the idle screw all the way in and it will now start w/o grabing the throttle. I then check timing. #1 plug looks right @ 10°-12° but it looks like 's not firing consistantly. I then look into the timing light and notice that it's definitely not blinking evenly. I check a few other plugs.. same story. Is is normal to have a timing light firing that unevenly? I thought the bad idle was a lumpy cam, but it is definitely missing and backfiring. I tried to blip the throttle but it didn't like that all!!! A lot of backfires. My gut says timing is way off but it checks OK - and have done so several times! I now thinking is spark related. Check the earlier posts as what I'm running. Is this C4 coil OK? It says is compatible with both inductive and CD ignitions. Has anybody run the Holley -160(or Late GM) distro. without a ignition box?
Again, thanks for any ideas..
-Bill

Alright, I loosing it here. I'm getting lost in this timing thing. I've set the engine as close as posible to 10°BTDC. Now with the engine "running" it shows a wandering 10°-12°.The computer reference is set to '10'. The spark map calls for 23°(I think) Now, I'm confused... what should I see on the damper while running? 23° or the 10-12??

Definitely sounds like an ignition problem. I'd get that squared away before you change too mush in the software. I haven't used the system you're using yet, but I have had my share of time behind the screen tuning standalone EFI systems. I also had an ignition problem that stumped me for a while. 1990 Eagle Talon 2.0 Turbo engine - Car idled fine and free-revved fine, but under a load it would break down. The crazy thing - you could swap the plug wires around anywhere you wanted and it wouldn't change how the car ran graemlins/clonk.gif

That particular system (Microtech) had a feature that would lock the timing at 10*. Once it's locked, shoot the pulley and line it up with 10* and then unlock it in software. At that point, it would jump up to 20-ish at idle.

I say hold off on tuning the engine until you get a steady spark. You'll pull your hair out if not.

Brian, you are right about the ignition problem. After about a half hour of breaking the engine in. The engine started to misfire. After a few hours of trouble shooting. I realized that only after the engine would get up to temp. It would backfire and everything. We narrowed the problem down to the ignition control module in the distributor. We replace it and the engine ran great.

Awesome. Glad to hear you got it running good now.

Are you running the Holley ECU and software? How do you like it? I've been tempted to put the Stealth Ram on my MC, but I've heard mixed review on the Holley setup. One of the locals has an Edelbrock TPI setup with fat injectors, dizzy and the Accel DFI unit he wants to sell me. For the price he wants, it's a steal. I just don't know enough about the Accel system to decide if it's for me or not.

I think it sounds like ignition too.

You remember to plug the pigtale back in after you got it timed before free reving??? If you left the pigtale unplugged and reved you have 10deg timing period.

Check firing order/coil/control module/distributor

and got back the 36lb inj base map. The raw fuel you were smelling was the fuel not igniting and being flushed out the back.

I've had nasty vacuum leaks on several engines, MAF and MAP and a small leak at a vacuum line wont make it run THAT bad.

I would assume that setup has a TPS (Throttle position sensor) and an IAC (Idle Air Control Motor).

With the throttle blades open more, the IAC has less leeway which is good. However, you need to adjust the TPS to read the proper voltage or the computer will think you are opening the throttle blades past idle and give it more that it needs.

Bill, I missed your earlier post. I am glad to see you have the engine running, also. The timing you should see on the Damper it the same that you should see in the spark map. The reference is just a baseline to get the engine up and running.

You should add a or subtract your reference timing in the computer till you get both timing on the damper to match the timing in the cells on the computer at the same RPM. I pulled the engine up to about 1500 rpm then about 2000 and shot it with the timing light. We added about 3 or 4 degrees on the reference timing and till we got the timing to match. I hope this helps.

Twilightoptics,
The Holley system does have the TPS and IAC. It sounds like you are use to the GM fuel injection systems like myself. The Holley system doesn’t care about TPS voltage adjustment. It calibrates its self from the voltage that it gets from the initial set up. I know this doesn’t sound right but it does. I learned this from tuning a F.A.S.T. EFI system. There system uses the same concept.
Its all in fun though graemlins/clonk.gif

If its "batch fire" it causes wierd issues as noted by "moving the plug wires around"........

Thanks for the replies guys.. I appreciate it! Tonight I hope to get a reading of the damper vs. the spark map. I'm going to re-read the manual (for about the 9th time!) about how to get the values lined up. On another note, if you haven't started a 500+HP motor just siting there in your garage like a lawnmover - it's quite an experience - nothing like having in a car in your driveway. I've attached a photo, hopefully it comes out.
-Bill http://www.audiovisionps.com/motown415-A.jpg

Yeah it's a GM computer system, I've got this motor in my thirdgen camaro (I know it's not a velle)

You did a GREAT job polishing that. Makes mine look half assed.

http://images.cardomain.com/member_images/7/web/331000-331999/331508_53_full.jpg

Hey Twi.. Looks Great!
Well, I KNEW it was something stupid causing my problems. I shoot the balancer while looking at the spark map and, though jumping around a little, it matched pretty close. But, I'm still worried about the randomly blinking timing light. So I check the coil. Sure enough, it not steady either. So I backtrack through all of my ignition assembly and remembered that I had removed the trigger module in the distro to find a mating connector for the coil hookup. I opened up the distro cap. Those two wires to the mag sensor stared back at me and sure had a guilty look about them. I swaped them, put it back together, and NOW I HAVE AN ENGINE!!! graemlins/clonk.gif
Again, thanks for all your help guys!
-Bill