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]

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 :lol:)

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 :rofl:

[TitaniumTT]

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 :lol:

[TitaniumTT]

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.

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.

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]

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.

[rx4ur7]

I concur with using not any starting fluids. Seen too many damaged motors in the past. Last resort only and use very little.
Generally if the compression is good enough to blow your finger off the hole and there are equal pulses the motor isn't the issue.
It's then down to fuel or fire,
-Fouled plugs are usually one of the most common things, even if they were brand new NGKS. I use known dead plugs to plug motor after assembly, during install. Take them out to do initial spin to blow out assembly goo and get oil circulating.
Fuel is disabled.
Then enable fuel and install good plugs. If it doesn't fire within 5 secs of cranking, something isn't right. If it was running fine when it came in or fine before it popped then I know I missed something putting it back in. On the few that didn't light right away it was usually electrical or vacuum related, electrical connector not connected, blown fuse, 2 had broken wires under the insulation, or vac line not on or cracked hose.

Back to your issue,
Put a known good stock box back in it, you just want to get it to start and go through some breakin. Better to run rich then, when you think of it. Just want to make sure it idles and doesn't have any leaks.
Disable fuel and clean it out well.
Make sure it is spinning over 200rpm higher the better.
quick check plug fire, plugs in wire out of motor against chassis, Of course - Don't hold them please. If you are getting a good blue white spark, install plugs. Enable fuel and try.
If it doesn't show anything in 5 to 10 secs. Pull the T plugs, check for fuel if dry, why? If wet pull L's, clean.
Disable fuel, clean out motor. Enable fuel, use something to clamp off the fuel supply hose. Small needle nose vise grips with pieces of fuel line on the jaws works really well. Install plugs, spin for any reaction. Sometimes they try to light.
With key on open and close vise grips.
Try again. If it lights then dies then open up the grips just enough to let a little fuel through. Might take a few trys to get it right. But when you do the thing will usually fire and idle.
After it runs 10 20 secs , slowly open the grips.
With that proceedure I can usually get the problematic flooded FC to run in 10/15 min.
If there is a hidden wire issue that is another thing.

[classicauto]

Swap the proper size primaries in and go from there.

Were the plugs wet/dry?
Did you check for good spark at the plugs with them on a good ground?

I'll have to agree that the 10" of vac while running seems very low. There's alot of possibilities as to why that would be, but the most likely is a vac leak...

I still say to check it over, and then bump start it (check over should include fitting proper primairies :) ). That way you'll at least be able get it running, assess vac leaks and get it up to temp to seat the seals a bit. If its got spark, and fuel and timed right - it WILL START EVERYTIME with a bump start, it can't NOT start unless something is broke.

[vex]

well, worked a little on it today. Checked a lot of things out.

First up vac leaks:
I've checked everything, new gaskets, new intake caps, etc. No way is it leaking in enough to keep it from starting.

Fuel:
I've done everything to check to ensure that I'm getting fuel in the engine except pulling the primary and putting voltage to it to see the spray pattern. Checked resistance, checked major components along the path, checked main relay. They all check in spec. While cranking I heard the high pitched tap of the injector firing as well. By all means, I should be getting fuel dumped into the engine.

Spark:
When I pulled the leading plugs I noticed they were wet, not a super flood, but enough to ensure that the spark plugs are getting fuel to ignite--at least I think they are. I didn't really focus on the spark to ensure that I have good blue spark or not, I'll check that next time I head out.

ECU:
I hooked up a stock ECU and still had the same trouble. No desire to start up.

When I came into the garage today, it actually started right up without issue, and attempted to stay started for a few seconds before puttering out.

I'm still scratching my head on this one. I may attempt to turn down the fuel pressure to around 10psi and crank it. If it still doesn't attempt to crank over, i'm not too sure what's wrong.

The plugs themselves don't look fouled, infact they look almost brand new. Can't really figure it out. It's behaving like there's no fuel in the engine, but the plugs get wet.

I've dropped in two cap fulls of 20w50 oil into the combustion chamber, but still doesn't want to turn over. Should I move to a lighter fluid (10w, 5w, etc)?

any other suggestions or comments for me to check?

[classicauto]

Does the Rtek show you a value for the coolant sensor? Wondering if its not applying enough correction for a coldstart.

How long has the total run time been now?

[vex]

Does the Rtek show you a value for the coolant sensor? Wondering if its not applying enough correction for a coldstart.it does. It reads the value just as it does for stock. I did notice however that it's reading it as a hot start or that the coolant is above a certain temperature... but that might be because I forgot to hook up a specific sensor. I'll double check that today as well.

How long has the total run time been now?

maybe... 20-30 seconds give or take.

I keep coming back to a fueling issue, but I just don't see how that is possible especially. The injectors were cleaned and flow tested. I believe I heard the high-pitched tap of their operation while cranking. They have the right size in there and are trimmed to be 460cc/min during operation and starting. I have fuel pressure.

Which leads me back to spark... but the engine kicks on for a second or two on the vapors of the starter fluid, not the actual fluid getting into the combustion chamber. I'm planning on pulling the plugs today and testing for spark on all four. see how it works out.

Still haven't gotten my compression tester back from the guy I lent it too, so I can't give accurate numbers, but I have reason to suspect that the map reading is actually low. While just cranking, not actually starting, the engine produced enough vacuum to surprise me how much air it sucks in while cranking (enough to create a big force to pull my hand away while it was cranking--feels much more than 10inHg, almost like a shop vac)

My problem has to be with one of those 3, otherwise it would be starting and running. Sigh, is there any "easy" way to see if the injectors are putting fuel into the engine?

[TitaniumTT]

If your plugs are wet and smell of fuel, they are getting fuel into the motor. How much or how little has yet to be determined.

We can go round and round but we NEED to start crossing things off the list.

First, I would make sure there are no electrical issues with the Rtek. I would double check everything electrical, sensors, injectors, etc etc etc. Make sure everything is square biscuits there.

After that I would make sure the timing is set correctly and there are no ignition comps advancing or retarding the timing. I set my timing and then tried to double check it once it first fired @ 5* ATDC and she almost immediately stalhed. Make sure the timing is firing ~ 0-5* BTDC while cranking. While dicking with the ignition system I would make certain that all the plugs are firing and that they are firing in the proper order.

Lastly, compression. If the motor is pysically incapable of running becuase of poor compression, all the horsing with the fuel system in the world won't make her run.

Basically I would make sure it can't be anything but the fuel system before messing around and trying to touble shoot it.

Anecdote - I had a 40 horse Merc that was running like crap. Usually it's the carbs. So I rebuilt the carb, cleaned it out and then reset everything to factory spec. The carb wasn't that dirty, but it wasn't clean. Thing still ran not very good.... interesting. So I checked the plugs. Fouled, but not horribly fouled. So I replaced them. Still not running the way she should. Now I'm getting pissed. Compression? Check that and it's great. Start troubleshooting some more and find that the spark is weak. Traced it back to corrosion inside the harness not giving the coils full volts. Had to replace the whole harness but she ran like a top. Actually just started the thing today for the first time this season. Not my boat BTW. Moral is, sometimes it's a bunch of little things adding up to make one big problem. So I would make certain that it's not a few little things - spark, compression, fuel - by checking that the ignition system and compression are tops before looking deeper into the fuel system

[vex]

Well, I think I isolated what the problem is. For whatever reason the injectors are not energizing. I've checked the main relay, the resistor pack, and the CAS. They are all in spec. I didn't have any procedures on how to check the individual circuits created while cranking, so I made do with a multimeter and trying to at least measure some voltage from the injectors. I would imagine that at least 2.5-5v would be applied for a brief period of time to the injectors. No luck. Didn't read anything. Tried it with both a stock ECU and the RTEk. No go.

So here's the problem:

Fuel is not being delivered to the engine, and what I was thinking was fuel was a fine film of oil. The spark is great, as is the compression (anecdotal evidence being a few cc's of fuel dropped into the manifold while I was removing the intake, when I was attempting to check the injectors the engine started right up from that little fuel that dropped in).

So the problem is electrical and occurs between the main relay and the ecu. Injectors are good, cleaned, flow tested, and ohm checked. I tried to check continuity between Black-Yellow on the connection to the main relay, and Black-Yellow on the resistor pack but read 0 continuity. So here's where I need help. How do I start checking what's wrong and what connections need to be made? I'll be looking over the FSM and trying to track down procedures for ensuring that the proper circuits are engaged. I'll also be posting in the RTek forum concerning trouble shooting of energizing the injectors.

So there you go! We've got the problem narrowed down to exactly what it is. No fuel because the injectors are not energizing.

[TehMonkay]

You should always get 12v to the injectors when ignition is on, ecu grounds the injectors to open them, if it's an 87/86 check the resistor pack as well it may be bad or disconnected it's around where the airbox is. Otherwise i'd say you probably have a bad fuse or your wiring harness is fucked. Also, NA or T2, what year exactly?

[vex]

87, na.

[TitaniumTT]

Doesn't the Rtek have some way to remove the resistor pack? Or could it be that the injectors are not Ohm'ed correct for the resistor pack?

[TehMonkay]

He should still be getting 12V though even if theyre the wrong injectors, unless maybe the test wasn't done correct?

[TitaniumTT]

12v+ he should be getting to one terminal. The other should be open. It should latch to grnd to complete the circuit and open the injector. So if he's testing across the two terminals in the injector clip, than yes, that would be wrong.

How the resistor pack plays into all of this I do not know without seeing a schematic. I I would imagine though that all it does is alter the resistance that the ECU sees of the injectors. I know that I would want to get rid of it though.... one more failure etc etc etc. If the resistor pack is fine and there is still no voltage to one of the wires while the key is on, I would start looking up the line allllllllllll the way back to the battery. That's really the only way to trouble shoot shit like this. Start at the end, and work your way back. Testing every connection on both sides of the connector until you find the one connection, or stretch of wire between the connection that has lost continuity.

[TehMonkay]

Yeah, make sure your ground is the chassis or battery when testing for voltage at the injector plugs.

[vex]

Got it to start and hold idle like a champ. Problem was a plug that looked as though it was all the way pushed in and making contact was not. The 12v reading was not being read to the injectors from the main relay because that plug was not plugged in. I've plugged it in and did a run on it, idle was perfect at 1000rpm (set a little high for break in).

I saw EGT's of 900-950 F WBO2 readings of 13.2-13.7 and vacuum at 20inHg, with a peak at 30inHg when I was still trying to dial in the idle.

[WE3RX7]

That is good news - i totally missed your problem and came back online in time for the solution :)

Good job on the rebuild man..

[rx4ur7]

A way to test injectors, remove rail to check operation, spray pattern and rate of flow.
4B-74/75 FSM 1988 F1-56 FSM 1990

Connector not on properly, think I mentioned that in a previous post. Common.

Same issue I had with my GSL-SE. Except the plug was on fine but the wire was broken under the insulation. As I probed for signal an inch away from the connector it showed correct readings. When I took the connector off and tested it the signals were intermittent. When I pulled on the wiring the insulation stretched, found the problem.

Two weeks ago had an FC that had intermittent running problems. On that one found a primary injector plug that wasn’t clicked on. He would hit a bump and it would start running bad, hit another and it would run fine. Had some other issues like fuel around injectors so had to replace all of the injector seals and orings. After replacing them and making sure all injector connectors were on it starts and runs great. We were also getting air past the injectors before replacing rubber. This was on a factory car that had never had to have any work done under the manifold. So it came from the factory this way. Amazed that it ran fine all these years. I was going to condemn the water temp connector (have seen plenty of them) because I could get it to run good or bad by playing with the wire, what I was doing was moving the injector wire at the same time. But couldn't tell it was injector until I pulled the manifold. Did not expect to find it not on completely.

This is one thing I have found on working on cars all this time, most running or starting issues are related to a missing or bad ground somewhere or one wire mucked up somewhere. Especially after an install where the vehicle was running before any work was done. This is based on working on factory platforms. When wholesale changes have been made all bets are off. But still comes down to comp, fuel and fire.

The FC3S is especially finicky with proper voltage and ground issues they are electronically overloaded as far as I am concerned. If they drop below 10V during cranking you will have starting problems flooding in particular. The ignition system really needs over 10v during cranking to give good spark. The motor also needs to be spinning fast enough. If it is 200rpm or less you can have starting problems, especially if compression is marginal.

Having a multitude of little problems ranks up there with something that has not been taken care of for a long time or someone else that is not familiar with it has done the work. I have seen my share of those. Have a turbo buggy in here now that was one of those. Mostly age and vibration related failures. Previous owners just drove it hard and put it away hot. (Not the 2 seater that is shown on the website)

Check and double check everything when you put the thing back together. Slow down to go fast. Also recommend sober and fresh.

Congrates on finding it.

[vex]

For more clarification, this wasn't the injector plug which you were referencing. This was a body harness plug close to the ecu which was only partially together.

Good read though none the less.

[rx4ur7]

Ah ha, Sorry about that then. Pretty much same thing though. There was one that I had that one of the wires had pulled out a little from the harness connector. Connector was clicked on and tight. That one had me going for a while.

Enjoy your ride now.