having trouble with my omni

[Ubmbass]

I am having a heck of a time getting this thing to run properly. I need some advice.. what does it sound like to you? We barely got it idling for the first time in the vid.


http://www.youtube.com/watch?v=ZXGeRKuHMqA

[shelbyplaya]

Sounds like a miss, Here's what you should check.

MAP: Make sure the vac is connected, make sure the MAP is good and make sure it's plugged in. with out the MAP it wont rev and will be in limp mode.
Injectors: Make sure they are all plugged in and are grounded proper.
Grounds: Make sure you have GOOD and SOLID grounds!!!!!
And last, Check your Ignition: Cables, Coil and Plugs!

I had an issue that sounded just like that and it turned out to be a poor plug connection at one of my injectors and it wasent fireing.

Have you checked for codes yet?

[turbovanman²]

What you using for engine management?

I would check the base program, grounds, fuel pressure, cam timing/base timing. How much vacuum are you getting?

[Ubmbass]

Ok.. I am getting around 13 inches of vacuum. I have crane 18 cams.. It's running the FAST engine management with and edist box to run distributorless ignition. I think the cam timing is off. I will try grounds and all of your suggestions and let you guys know how it turns out.

[turbovanman²]

13 inches is very low, it could be cam timing or if the cams are wild, then that.

[cordes]

It sounds to me like the timing is way off.

[BadAssPerformance]

Ok.. I am getting around 13 inches of vacuum. I have crane 18 cams.. It's running the FAST engine management with and edist box to run distributorless ignition. I think the cam timing is off. I will try grounds and all of your suggestions and let you guys know how it turns out.

Def sounds like big cams... also that cal I sent you is fat as hell. Is that the one you got it ruunning with? did you confirm the crank reference with the ignition timing? Once that is set, adjust the VE table in the idle RPM range up so that the so that the idel A/F is like12:1 (yes that rich) and then add ignition timing (again at idle RPM) until the vacuum stops increasing. Then double check A/F... should idle better then...

The e-mail with the cal had some 'itno to FAST tuning' tips in it right? feel free to call me...

[Ubmbass]

I haven't put that cal on it just yet.. I am trying that today.. I have not checked the timing just yet. I'll do that too.

I am worried the cam timing is off. when I check the timing on the torque converter, will it read wrong if the cam pick up is off? I am going to machine the slots for the cam mount out so I have more adjustment. or should I leave it and try something else?

I really think the vacuum is caused by the high elevation and the big cams. I'm at 4400 ft here.

[BadAssPerformance]

The cam sensor is just a check to tell it which stroke it is on, if it runs and revs, it is set correctly.

The crank sensor is the base pick up for ignition timing.

Cam timing is 100% mechanical referenced to crank #1 TDC

[Ubmbass]

OK, so I shouldnt really have to worry about it.. that's good to know. I won't worry about messing with that mount.

Well I got some work to do. Thanks for all your help JT!! I need to set timing and work with the fuel some more.

ok.. also, it only revs to around 4700 then wants to stop revving. it seems like it would rev higher, but I dont want to push it too much. it seems like it wants to backfire and spit fireballs out the exhaust.

[Ondonti]

you lose 4+ inches up here :(

[Ubmbass]

agreed. I have experienced this first hand going from here to phoenix..

[BadAssPerformance]

OK, so I shouldnt really have to worry about it.. that's good to know. I won't worry about messing with that mount.

Well I got some work to do. Thanks for all your help JT!! I need to set timing and work with the fuel some more.

ok.. also, it only revs to around 4700 then wants to stop revving. it seems like it would rev higher, but I dont want to push it too much. it seems like it wants to backfire and spit fireballs out the exhaust.

Glad to help :thumb:

for fuel, set base (no vacuum) to 43-45psi and then use the VE table as needed.

Hmm 4700? try the other cal and see if it changes that once you start getting it tuned. If then it still does not rev higher than 4700 it might be a cam sync issue, something about cam angle vs crank angle, but there are ways to trick it....

[Ubmbass]

those ways being???? lol

[BadAssPerformance]

Does it not rev over 4700?

One way to check, with it running, unplug the cam sensor and try to rev it higher. If it doesm it is a cam sync issue. A couple ways...

One is to actually fix the cam reference to crank reference to make them further apart, being that they are too close and at higher RPM they F eachother up.

Another is to selectively read the cam sensor. It should only read the cam sensor until it is running, so you can only power the sensor during cranking and not once it is running...

Kish did the second on his Neon and it works well... his also would not rev before doing it. I did not have to do it, so my only guess is I have a better cam sensor degree?

[Ubmbass]

I haven't really had time to play with it yet since you sent me that tune again.

So, it doesn't need the cam signal when it's running? It just needs it during fire up? That's interesting. I will try that when I work on it next.

So, when I check the mechanical timing with a timing light, how do I adjust it if it's a few degrees off? With the crank reference angle in the ccom software? Sorry for all the stupid questions, I'm just new to this whole DIS thing and I appreciate all the help you guys give me!

[BadAssPerformance]

Try to get the cal and timing squared up a bit before trying to rev it again, it could just be choking on raw fuel?

Check the cam mechanically with a degree wheel and your timing marks to make sure the cams are straight up at crank #1 TDC

Check the ignition timing reference by setting the whole spark table to one value like 20° or something temporarily. Then check your crank timing mark with the timing light to see if it is at 20° (or 0° with a retardable light) and yes, if it is off, adjust your crank reference to make up for it.

For some reason some timing lights have issues with the DIS and the light will flash at your reference angle instead. mine did this so I flashed the light on the crank trigger wheel and looked or my #1 TDC mark there to zero it :thumb:

Cam sensor is only used to tell which stroke the cam is on vs. the crank cuz the cam rotates once for every 2 crank revs.

[Ubmbass]

Yeah, I remember you telling me that once before, I just was unaware of the fact that it's only supposed to reference it during cranking. That's very useful info.

I will play with the timing and fuel no later than this friday (my day off) and let you know. If I can get some time, I will do it sooner.

I wouldn't doubt that it's choking on raw fuel. It has very large injectors as you know LOL!

[BadAssPerformance]

Yeah, Kish figured out that trick on his Neon. FAST said it wouldnt work. He tried it and it did so he wired the cam sensor so it only has power when the starter is cranking...

[Ubmbass]

badass.. I will definately try that if it doesnt work doing all the other stuff.

[BadAssPerformance]

cool :thumb:

[Tim Kish]

As JT said, I had a similar sounding issue at about the same RPM. Acted like a rev limiter was set. When we disabled the cam signal after engine start the problem went away and I've run the car for 3 years now this way turning 9800rpm with no issues

[BadAssPerformance]

Cool, thanks for chiming in Bro! :thumb:

[turbovanman²]

I've run the car for 3 years now this way turning 9800rpm with no issues


Holy crap, :wow1: Whats your setup? :D

[BadAssPerformance]

Tim runs an all motor neon in SS/GS :thumb:

http://dragracecentral.com/stories/photos_go_here_06/Hebron06_103.jpg

[turbovanman²]

Way cool, :thumb:

Times, setup? :nod:

[Ubmbass]

well, sounds like it is about what I am going to run.. Plan on spinning 9700.. but that's besides the point now. I need to get this thing running right.

I tried the cam thing and it didn't do it... I found some wires were wrong. I fixed them.. now it won't run again. HAHA>.. I had the wires going to the dis-2 were wrong. I fixed them. also, the wires going to the coil pack were wrong. It was wired with the power going to the 1-4 and the 1-4 trigger was going to the power... I don't even know how it was running. Now I can't get it to run.. it's really starting to piss me off.. I am at a loss. It starts, then dies,. any ideas would be greatly appreciated

[Tim Kish]

Way cool, :thumb:

Times, setup? :nod:

Not to hijack too much - 2.0L DOHC (Darrell Cox built), lots of cam, lots of compression, aforementioned lots of RPM and custom automatic trans. Best time: 12.880 @ 108.44

To your issue: Coil pack wiring - factory supplies common power with ground outputs from the ECU to each side of the coil. MSD/Crane outputs are positive so the center common lead is ground.

Crane wiring diagram
http://www.cranecams.com/pdf/90006500c.pdf

[Ubmbass]

SO, you are sure the MSD DIS-2 pulses the positive? I have it wired completley different than that. CRAP!! I hope that is the problem! If it is, I will have to just kiss you tim!!! Thanks

[Tim Kish]

You ever get your car fixed?

[BadAssPerformance]

Last I talked to Corby he got it running but needed to tune it... and he did trick the cam sensor similarly to yours.

[Ubmbass]

Yeah, I got it running after a lot of playing around with the fuel map.. those big injectors don't like to idle very well.. Now I have it torn apart to fix the intake so it doesn't get too close to the timing belt and still be able to use the stock tesioner.

YOu know, it still doesn't run "right" it's really hard to start, idk if it's the e85 and it being as cold as it is, or what.. I'll figure it out after I get it running right again. THanks for all the help guys!

[BadAssPerformance]

I've played with the VE and timing tables in the idle range to help starting... there is also an air temp vs. fuel enrichment table.

[Ubmbass]

Yeah, I was looking at that.. You know, my air temp sensor doesn't work properly. It shows way colder than it could possibly be. so does my coolant temp sensor. I used the same coolant temp sensor as before in the van that seemed to work perfectly fine, but I used a stock neon air temp sensor and it reads way too cold.. like 25 degrees when it's 40 outside.. IDK it just seems like it would directly affect the tuning of the car wouldnt it?

[BadAssPerformance]

Yes if the different sensor has a different voltage range it will read differently and thus affect the cal. I thought they were kinda standardized tho?

[Ubmbass]

same here. but we'll see

[turbo2point2]

Not sure which sensors you have in there, but I know when I plugged in a TD sensor on my car the numbers were off a bit. My system calls for GM air temp and coolant temp. sensors only. Just a thought.

[Ubmbass]

I'll see what I can find out about my sensors

[BadAssPerformance]

True, FAST uses all GM sensors for the most part... I am using a 2.2L TPS tho.

[Nemesismachine]

Did you build this car with all the gofast goodies at the same time? Buddy of mine works at a shop near my house, and he had a kid in an evo buy a LOT of parts and put them all on at the same time, and his car wouldn't start. Without knowing how the car will act with all the aftermarket stuff on, it was hard to troubleshoot. He ended up having to basically rebuild the engine with stock parts, then swap out for the performance ones one at a time.

Maybe not your issue, just chiming in. :)

[8valves]

CTS and CAT sensors are usually critical sensors to a standalone, and will highly affect how it runs. Espescially startup!

[Ubmbass]

Good point. I will see what I can do about the sensors.. Thanks guys!
And yes, I did build it all at once. I know it's difficult to get to start this way. I swear I will not rebuild this thing again. lol