Starting a fresh rebuild

[vex]

I seem to have some trouble starting a fresh rebuild.

The seals are new, the apex seals are new, but the housings are used as are the side seals and corner seals. All springs have been replaced.

I have spark at the coils.
I have air without issue.
And I have fuel pressure and I hear the injectors firing (I know they're good because they were cleaned and flow tested).

By all means I should be getting at least an attempt to start. All I get is it cranking. Strong exhaust pulses can be heard so I don't think it's anything catastrophic. I would however like some sure fire ideas or ways to get this thing to start.
(I've already primed the oil system)

[TitaniumTT]

What ecu? Are the plugs firing? Spark at the coils doesn't necissarily mean that the plugs are firing. Is the timing set and double checked?

[vex]

Originally Posted by TitaniumTT

What ecu? Are the plugs firing? Spark at the coils doesn't necissarily mean that the plugs are firing. Is the timing set and double checked?

The ecu is an RTEk 2.1 (basically stock with controls). I stabbed the CAS and will double check it when I go out there tomorrow. Assuming that that is okay and there are no issues with either of those (spark at the plugs and timing set), what else can I do/check?

[TitaniumTT]

Grab a bone stock ECU and try that. For whatever reason, I know for a fact that an Rtek wouldn't start a car, but the stock did. So there's something wrong with the Rtek right? So it goes back to Digital tuning, they check it out, say there is nothing wrong with it and send it back. Plug it in, car won't start. Plug the stock in and it fires right off. No idea what the problem was, sold everything to go LSX so we never figured it out. The ecus went to other people that have had no problems, and the harness went to a guy who as far as we know, hasn't had any problems either. Wierd wierd things with electrical shit sometimes. My personal thought is it was a pin not making contact.

[vex]

I don't think it's the ecu as I get connectivity status on it, and have programmed it up to the injectors already. Going to stock will cause me to run too rich on startup. I could try it, but I don't think it'll start that way either. I suppose I could do a compression check and see the numbers. Though I highly doubt the compression would be super drastically low, but I have heard of individuals having issues starting fresh rebuilds like that.

If I'm getting spark and fuel (whether it's anecdotal or not is another matter) wouldn't that indicate that the ECU is infact working?

[NoDOHC]

Try some starting fluid... That is how I got the 4-port lit. Once it is running, you should be good to go (assuming you have a decent tune).

I discovered that the priming pulse that was required for a fresh rebuild is insanely long relative to a broken-in engine.

Even if the timing is off 90 degrees, you should still get some fire out of the intake or exhaust.

Did you check spark with an inductive timing light?

Spraying the starting fluid will indicate whether it is a fuel or spark issue (if it starts on ether, it is fuel related. If not, spark related.)

[classicauto]

Pull you spark plugs after a few tries at cranking and look for:

Fuel on the plugs?
Lay them on a good ground and look for strong spark? (don't forget what'll come out of the housings if you had fuel on the plugs )

If you have fuel getting into the engine, and good spark:

Tow strap and about 100yards of clear pathway + something to tow it with. If it doesn't bump start - you have a serious fucking problem

[TitaniumTT]

Originally Posted by NoDOHC

Try some starting fluid... That is how I got the 4-port lit. Once it is running, you should be good to go (assuming you have a decent tune).

I'm not a big fan of starting fluid at all. Not in the least. It dissipates the oil that should've been smeared on the housings to protect all the seals upon startup.

Ever see someone use ether on a diesel engine? It generally kills the engine after a few times becuase it just wipes the oil off the valves and the rings.

[vex]

well, I have the engine kicking over but it doesn't stay on for more than a second. I took a lot of data logs when I was cranking it and will load them up shortly once I hotsync the Palm. what I noticed after the time cranking it, that although I was no longer using starter fluid it would still start, the more often I did this the more the engine pulled in vacuum. I even was able to get up to 10 inHG+ when it starts.

The problem is keeping it started. still having some mysterious issues with it--but will be looking into it more.

[need RX7]

Well if starting a fresh rebuild is anything like starting any other low-ish compression motor, a little oil in the spark plug holes works every time. Clean you plugs after.

[vex]

here are some data logs. I'm still working out an issue I have with the ecu... for some reason it's not understanding to record the WB properly... Though I was no where near lean in any of the attempts to start.

The Comma Delimited Files (for when you import them into excel or another spread sheet) are setup as this: year/month/day/time. I grabbed the earliest one recorded as well as some others that are prevalent throughout the night of starting.

what I've noticed is that after I have it start I have to wait at least 5 minutes before attempting to start it again, else it won't actually catch and rev up to 1k. Beyond that, I'll let the datalogs speak for themselves.

EDIT: I've also confirmed my suspicion; I've installed my secondary injectors in my primary position and my primary injectors in my secondary position. So instead of having (550/720) I have (720/550). Opps. I'll correct that grievous error tomorrow. Think that has anything to do with my logs? Or will fixing those actually accomplish anything?

[MaczPayne]

It's possible, you might be flooding out the engine with the larger secondaries in the primary position.

Vacuum leaks will also make it very hard to start. I had the same problem with my fresh rebuild, found maybe 2 vacuum nipples that weren't capped. Squared that off, and the motor started up easy.

[need RX7]

It seems plausible that having larger-than-expected injectors in the primary position could cause the motor to flood every time you try to start it.

EDIT: MaczPayne beat me to it

[TitaniumTT]

Originally Posted by vex

well, I have the engine kicking over but it doesn't stay on for more than a second. I took a lot of data logs when I was cranking it and will load them up shortly once I hotsync the Palm. what I noticed after the time cranking it, that although I was no longer using starter fluid it would still start, the more often I did this the more the engine pulled in vacuum. I even was able to get up to 10 inHG+ when it starts.

The problem is keeping it started. still having some mysterious issues with it--but will be looking into it more.

10" vac is pretty low. I'd deflood it and run a comp test to se where you're at with the motor.

Starter fluid is bad. If there was any scoring to be done, the starter fluid just helped it along.

Originally Posted by need RX7

Well if starting a fresh rebuild is anything like starting any other low-ish compression motor, a little oil in the spark plug holes works every time. Clean you plugs after.

Good call, but I'd be interested in what the comp is like.

Originally Posted by MaczPayne

It's possible, you might be flooding out the engine with the larger secondaries in the primary position.

Vacuum leaks will also make it very hard to start. I had the same problem with my fresh rebuild, found maybe 2 vacuum nipples that weren't capped. Squared that off, and the motor started up easy.

Vac leaks definately need to be found. Rtek runs a MAF system correct? Vac leaks will make it run lean though becuase it's letting unmetered air in.

If you're of the thought that the larger injectors are making it run rich, kill all possible vac leaks first.
Do you have an adjustable FPR?
Do you have a fuel pump kill switch?

If you have an adjustable FPR I would turn the fuel pressure WAY down and see what happens. If you don't have an adjustale FPR, try hooking up a miti-vac type dealy and lowering the pressure that way. What are you running for a pump and regulator?

If you have a fuel pump switch I would crank the car over for a second or two and then turn the pump on.

Let us know. I'm curious. Especially about the comp. After Goodyear severely overheated my motor I did a comp test and got 90psi F, 100 psi rear with one REALLY low bounce, as in ~75 psi low (flattened spring or warped apex seal, possibly scored housings) Not exactely what I would consider a motor that is within factory spec and I was still pulling 12-14" @ idle. When the motor had 50 miles on her I was getting 16-17" of vac and running 105 Psi F and 110 psi R, when the motor had 50 miles. I would be VERY curious as to what your comp is.

[vex]

Originally Posted by TitaniumTT

10" vac is pretty low. I'd deflood it and run a comp test to se where you're at with the motor.

Starter fluid is bad. If there was any scoring to be done, the starter fluid just helped it along.

I doubt very much that the starter fluid actually stripped any oil from the engine as I wasn't spraying directly down the throttle body. I would just let the vapors of the spray get pulled in from the intake piping while I was cranking.

Good call, but I'd be interested in what the comp is like.

Me too. Unfortunately my friend still hasn't returned my compression tester to me.

Vac leaks definately need to be found. Rtek runs a MAF system correct? Vac leaks will make it run lean though becuase it's letting unmetered air in.

There may be possibilities of a few vac leaks, but I've capped off almost all the nipples on the intake. I'll attempt to hunt them down and see what happens.

If you're of the thought that the larger injectors are making it run rich, kill all possible vac leaks first.

I will, I was thinking that I'd switch the injectors so I don't have to worry about it anymore. I'll then tackle hunting down any and all vac leaks.

Do you have an adjustable FPR?

yes

Do you have a fuel pump kill switch?

no

If you have an adjustable FPR I would turn the fuel pressure WAY down and see what happens. If you don't have an adjustale FPR, try hooking up a miti-vac type dealy and lowering the pressure that way. What are you running for a pump and regulator?

I'm running a 3rd gen pump, and an adjustable 1:1 rising rate FPR from aeromotive

If you have a fuel pump switch I would crank the car over for a second or two and then turn the pump on.

Let us know. I'm curious. Especially about the comp. After Goodyear severely overheated my motor I did a comp test and got 90psi F, 100 psi rear with one REALLY low bounce, as in ~75 psi low (flattened spring or warped apex seal, possibly scored housings) Not exactely what I would consider a motor that is within factory spec and I was still pulling 12-14" @ idle. When the motor had 50 miles on her I was getting 16-17" of vac and running 105 Psi F and 110 psi R, when the motor had 50 miles. I would be VERY curious as to what your comp is.

I'm fairly certain that the compression of this engine is fairly low since I haven't been able to run it for any specific amount of time to allow the apex seals to wear in. But if I get my comp tester today I'll post up the numbers.