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View Full Version : Rebuild is not starting...help


supernaught
06-25-2009, 11:03 AM
I'll give you the quick rundown.

I wanted to redo almost everything under the hood(my harness had some shitty splicing, a couple sensors were intermittant, I had a slow drain).

I just happened to have a ported/polished head with 272 cam, so i installed it when i saw my old head was filthy.(all new gaskets and seals, bolts)
Installed a engine harness from my parts car IX(same year, both auto) but the only custom wiring I had to do was redo the O2 sensor wires and the oil level sender. Also there is 2 connectors that go through the firewall with the main harness and connect to in-car connectors beside the ECU. These are not connected since the connectors were slightly different and the wire colours not the same.
In the new head I installed 19lb injectors I got online(not tested when i received them) and a used injector harness that I rung out fine.
Has all new: Cap rotor, CPS, spark plug wires, tbelt, tensioner, water pump, alt and ps pump belts, new fuel lines, all new coolant hoses.

Had bad starter so that was replaced with a rebuilt one.
Had an issue with no fuel pumping, replaced it but it turns out I had the CPS and Timing sensor reversed. Fuel pumps ok to the rail now.
But I can't tell if the injectors are firing or if there is actually a signal getting to the injectors. I am picking up a stethescope and timing light this week.

So, I tried cranking and cranking and no start. it won't catch or fire any cylinders.
So I checked the New spark plug wires, held to the block and could hear them poping. So I installed brand new copper plugs. No change

In my haste to assemble the engine, I installed a 2.5 bar FPR, and thought that might be the problem, but installed a proper 3.0 one and had the same result.

So I started to pull the injectors out(without removing the intake mani) to swap them with the ones in my rallyxcar and in doing that I broke a pintle cap off of one of the injectors.

So now I have to pull off the intake, fish out the cap, get some good stock injectors and find out what the mystery wires beside the ECU are for.
And hopefully with new injectors and proof that they are getting signals, I will get some spark.

The car has been sitting since the fall(under a tent) so I even thought it could be the fuel, so I drained it all out and poured in 15L of new shell bronze.

Fuel to the rail looks good, spark seems to be good(will do proper test friday), timing is good, so could all my injectors really have been shit? or is there some majical logic in the ECU where it is not allowing the injectors to fire because of some unknown(to me) condition?
What if my TPS was malfunctioning?


Thats what I think. Bad injectors or the ECU isn't happy.(I now have a spare ECU to try on fri)
Any wise comments?

I'd test a lot of these things right now, but I don't see the car during the week.

Thanks
Rob *drink*

BigD
06-25-2009, 11:59 AM
I would tripe check the CPS. A dead ecu would cause this but a bad CPS signal definitely would. Put an oscilloscope on the injectors to see the pulse train, and pull out a sparkplug, put it against the valve cover, see that you're getting spark. If both of those are flatline then it's either the CPS or the ECU. If you have both, then it's fuel. I may be wrong but I don't think anything else would cause it to not start - bad afm or tps etc will cause it to run badly or die almost right away but it should at least catch. Right now you're missing something fundamental from air/fuel/fire.

EDIT: if you have spark but not injectors, then it's probably a bad or disconnected ground on the injector harness.

supernaught
06-25-2009, 01:15 PM
thanks for the suggestions. I know my ECU is doing something, otherwise my fuel pump wouldnt work, but checking the ground on the injector harness I have not done.
I will check these things once I replace the intake.
thanks

supernaught
06-27-2009, 10:01 PM
ok, news from the project
I found some new injectors, could only find some 19lb ford from a 98 windstar, stuck them in and found one leaking. hooked up the rail with injectors pointing at a long sheet of papertowel and I found they all worked but one(stuck open). Replaced it with one of my older ones(another 19lber) and all 6 have an even spray and intervals look good.

Checked each plug for spark by holding the plug in the wire against the head and each has spark, some looked kind of yellowish but mostly blue

Checked compression, found 125-130 across all cylinders.

So, if I have fuel, and I have spark, and I have compression, whats left? Spark timing, injector timing, Cam? I know the timing marks are lined up perfectly, tensioner is just right.

I know the cam was done on this head before I got it, so I don't know if there was anything funny about it, but as far as I know theres only one way it can go in, right? Theres no way to put on a pulley and or rotor on incorrectly when installing right??

This is messed up.

everlast
06-27-2009, 10:11 PM
125-130 seems low for compression but might just be inaccurate. Perhaps the timing is off since you had the head off? I think it could be one revolution out, causing it to spark on the decompression stroke.

You're not flooding the cylinders to the point they won't fire?

BigD
06-27-2009, 11:21 PM
Check that you have power at the injectors and the harness gruond is ok. Sounds like the ECU is not opening them. If all of the above are fine then it's the ecu. 125 compression is fine for a cold engine. Even with totally screwed timing it would at least pop.

supernaught
06-27-2009, 11:22 PM
so i just read it should be around 140-155 psi, could just be my tester needs a kick in the ass.

And the way I read it, if the timing was out by that much, the pulley would have to be out by 180' since the timing marks line up. And as long as the crank is lined up it shouldnt matter.
Can the cam pulley be put on 180' out?
If it WAS out 180, what is the best way to tell what is correct? I can take off the valve cover and verify which valves are open...

BigD
06-27-2009, 11:26 PM
Did you test a cold engine? Even if you didn't, 125 is not 0, it'll still work, just not as well. These are interference engines - if your timing was out of whack you'd have cylinders with 0. Don't overthink this.

supernaught
06-27-2009, 11:29 PM
Check that you have power at the injectors and the harness gruond is ok. Sounds like the ECU is not opening them. If all of the above are fine then it's the ecu. 125 compression is fine for a cold engine. Even with totally screwed timing it would at least pop.

I had the injectors connected to the harness, and the rail, with the rail connected to the pump, FPR, etc, but not actually in the intake, I laid it all on the valve cover, ontop of a plastic sheet with some paper towel. I had someone turn over the engine so I could visibly SEE the injectors firing on and off. I did, and therefore believe they are working.
I could not determine if they are firing in the correct intervals or timing though, and I don't have reasonable access to an oscilloscope.
So from what you suggest it could be the ECU. I will have to try out my chipped one in the morning.

Anyone have any suggestions regarding the cam pulley/timing?

supernaught
06-27-2009, 11:31 PM
ya, engine has been cold for a long time now. I didnt think it was possible to have the timing out like that, but then again, I've never had a head apart, just off.

BigD
06-27-2009, 11:58 PM
Hmm, sorry I didn't get that you actually tested them being fired by the ecu, I thought you were just shorting them open yourself. If you've got spark and injector signal then the ecu is doing its job. I guess your timing is really so far off that it's not even catching.

supernaught
06-28-2009, 12:18 AM
didnt think it was possible.
in any case, I just checked the cam orientation at TDC on this head vs the head i removed and it is the same. it doesnt make me feel cozy though. I'm still looking for a smoking gun.

I can tell you all that everytime I try to crank it a few times(with assumed fuel injection), I pull the plugs and let it sit a couple hours to clear up.

For injector timing(not incl duration), I am sure the ECU handles this entirely and calculates timing based on spark sensor and CPS.

Either way, I'm still hearing no pop of cylinders firing. Probably only two or 3 times, but never in succession.

supernaught
06-28-2009, 12:24 AM
I'm going to drop in the other ECU in the morning for the **** of it. I have no idea.
And ill drop in my spare ign coil.

supernaught
06-28-2009, 12:05 PM
just installed the spare ecu and coil.
I pulled the fuel pump relay for the first few cranks of the morning(10am - it sat since 10:30pm) to see if there would be a difference if I let out the pressure.
While cranking with no pump on, I actually heard it catch on a few cylinders. then it cut out.
I tried again and nothing, reasoning that it really does have no fuel.

Put the relay back in and cranked it again, but nothing this time.

I am wondering if it really is getting flooded like everlast suggested.
Whats the best way to confirm this?
Why would it be happening? What control injector duration? temp sensors? CPS?

supernaught
06-28-2009, 12:44 PM
FWIW there is no coolant in the engine. I've had to pull the head/rad a few times and didn't bother to put any in since(about 2 weeks).
Maybe the tempsensor thinks the engine is super cold and trying to start it uber rich? flooding everything?

I think I might try holding the sensor in some warm water and see if that makes a difference.

BigD
06-28-2009, 01:19 PM
The temp sensor just tells the ecu when it's time to start listening to the O2 sensor and lean out the motor.

Check your fuel lines, maybe you have them reversed (supply/return)? I'm just clutching at straws here... this shouldn't make it even pop...

Are you sure you have the right fuel regulator? Get a fuel pressure gauge and hook it up at the fuel rail, that'll tell the tale once and for all.

supernaught
06-28-2009, 01:27 PM
going to CT to pick one up now(pressure gauge)
Thanks

InfiniteDice
06-28-2009, 01:45 PM
Does the small wire from the battery have voltage, disconnect it from the power terminal under the hood. - That would be the fusible link in the trunk - it would cause a no start.

On the older cars you have the sensor pickups on the tranny. The newer cars have 1 wire to spark plug 1, and 1 to the crank. Test those for the right values, the test is online.

The relays, it's good to have a few of each to rule them out.

If the ICV is acting up there will be no buzz, and that is the only way for the car to get air while idling, so keep the pedal down and try starting it... if you let off the gas and it cuts out, it could be the icv.

The TPS has to click just as you start to open the TB, if not re adjust it. This could flood the engine if it's not set up properly, Take out a spark plug if you smell strong gas, then its' flooded.

Did you test the coil? and do a spark test off the coil with a spare plug, ground the plug body and look for spark between the gap. Wear some rubber gloves or something :)

The wiring harness would be the last thing... check each wire from end to end to rule out a bad wire.

Keep posting here, and you'll get it started! Good luck man!

mirek
06-28-2009, 05:23 PM
Check your fuel lines, maybe you have them reversed (supply/return)? I'm just clutching at straws here... this shouldn't make it even pop...



had this problem when rebuilding my m20, switched it and it started right up.

supernaught
06-28-2009, 05:29 PM
had this problem when rebuilding my m20, switched it and it started right up.

I thought this might be the issue at one point so I switched them, no good. Switched them back to the correct way now.

supernaught
06-28-2009, 06:06 PM
Does the small wire from the battery have voltage, disconnect it from the power terminal under the hood. - That would be the fusible link in the trunk - it would cause a no start.
if this was the issue i think it wouldn't crank/pump fuel - which it does


On the older cars you have the sensor pickups on the tranny. The newer cars have 1 wire to spark plug 1, and 1 to the crank. Test those for the right values, the test is online.

I tested my CPS and it has good resistance, actually had the crank and spark sensor reversed for a bit, but now they are correct. Without these the fuel pump relay will not operate.


The relays, it's good to have a few of each to rule them out.

These all checked out ok, I have a bunch of spares


If the ICV is acting up there will be no buzz, and that is the only way for the car to get air while idling, so keep the pedal down and try starting it... if you let off the gas and it cuts out, it could be the icv.

ICV buzzes, tried cranking with the pedal depressed, no difference. And it won't catch so letting off does nothing

The TPS has to click just as you start to open the TB, if not re adjust it. This could flood the engine if it's not set up properly, Take out a spark plug if you smell strong gas, then its' flooded.
I am definitely smelling gas when a plug is pulled but I know I'm getting spark so it must be too much fuel...? Can't figure out why the computer is putting so much fuel in. I will play with the TPS to be sure.

Did you test the coil? and do a spark test off the coil with a spare plug, ground the plug body and look for spark between the gap. Wear some rubber gloves or something :)
yup this was tested a few times, even replaced the coil with same result


The wiring harness would be the last thing... check each wire from end to end to rule out a bad wire.
I'm actually going to do the full Motronic Control unit Electrical tests as laid out in the bentley(Fuel System 6.4 pg 49) when the rain lets up a bit.

BigD
06-28-2009, 07:50 PM
Let us know what you determine the fuel rail pressure to be.

supernaught
06-28-2009, 10:19 PM
CT was sold out of anything that would read fuel pressure and they were the only place open where the car is. I'm going to pick one up first thing in the morning and head back up to the car to test it out.
I expect it will be within tolerance, and I did also try to start it with a 2.5 bar FPR as well and it had no success.
Also going to put in some coolant and check the TPS.

Anyone have any idea what the connectors beside the ECU are for?

InfiniteDice
06-29-2009, 12:48 PM
Ok... man I gotta tell you to go and physically check that fusible link in the trunk. #1 yes the car will still turn over. #2 yes it will still pump gas.

I had that issue for over a week, I was at my wits end! Finally found out about that link and when I pulled the shrink tube and the link was all corroded and fell apart in my hands.

If you don't want to look at the link, at least remove the small lead from the block under the hood, and then test it for battery voltage. I would keep the volt meter on it while you try to crank it. Mine showed fine until I tried to crank it and then it showed a big drop on that wire. The link can pass some voltage but under load it will not work.

Best thing is it doesn't cost you anything to check it. The fuse is 18$ at the stealer.

supernaught
06-29-2009, 03:03 PM
Ok... man I gotta tell you to go and physically check that fusible link in the trunk. #1 yes the car will still turn over. #2 yes it will still pump gas.

I had that issue for over a week, I was at my wits end! Finally found out about that link and when I pulled the shrink tube and the link was all corroded and fell apart in my hands.

If you don't want to look at the link, at least remove the small lead from the block under the hood, and then test it for battery voltage. I would keep the volt meter on it while you try to crank it. Mine showed fine until I tried to crank it and then it showed a big drop on that wire. The link can pass some voltage but under load it will not work.

Best thing is it doesn't cost you anything to check it. The fuse is 18$ at the stealer.

Cool, I wasn't aware it would till crank if the link was bad. I WILL check that for sure this afternoon.
My main curiosity right now is the 2 connectors beside the ECU. I think I read that one is for the Park/Neutral signal to the ECU, and if it not connected, I should not get good spark or fuel.[I believe the other has to do with the A/C]
While I understand this theory, I KNOW that I could see some spark on every plug and I KNOW that I saw(visibly) that the injectors were spraying at intervals. Whether the timing/duration/effectiveness is correct, I hope to find out when I connect a few things. This better be that ****ing smoking gun I've been looking for.

Thanks
Rob

BigD
06-29-2009, 04:25 PM
With the park/netural switch off it won't send any spark or fuel. I also don't think it will crank with the fusible link broken, it certainly won't be sending spark or fuel. I'm honestly at a loss here. You're either misdiagnosing something (ie something you tested as good is actually not) or there is some really screwed up problem I've never heard of. Fuel, ignition, air and compression is enough to run an engine, at least for a little while, badly. Everything else makes it run well. I've had an engine with the balancer loose, so the ignition pulse was coming totally randomly (as the timing wheel rotated on its own apart from the engine). The car would usually start and just misfire like crazy. I also had an engine with many bent valves. It started and ran until all valves were bent and 2 pistons broken.

supernaught
06-29-2009, 07:33 PM
BOUJAKASHA!!! ITS ALIVE!!

C131 was not conencted. I had to modify one of the connectors a little to make it fit. It is the signal from the Park/Neutral Switch(at C306) to the ECU(pin #42).
The signal is split at C306, one wire goes to C131 and the other goes to the main relay. The switch was functioning correctly, therefore so was the relay(and crank, spark).
Once I connected this wire, it fired right up. A little plume of sunflower seeds and mouse nest came out the exhaust but nothing I can't handle.

Idle is lumpy as hell, but hopefully it will work itself better after some running time and after I install the chipped ECU.

Thanks for all your help guys!

Next step - get it running smoothly.

Cheers
Rob

richie_s999
06-29-2009, 11:53 PM
Does this mean your down for the next Durham cruise in a few weeks!!!! :P

supernaught
06-30-2009, 12:15 AM
it seems that way doesn't it!
I just have to smooth out the idle, the chip and the M30 AFM + cone will help when I get those in. Right now she's drowning in fuel after about 30 seconds of running.
But it sounds like a monster now. A bit more of a roar than she used to have.
I'm VERY excited to have this bitch alive again.

BigD
06-30-2009, 02:16 AM
I still don't get how it didn't run with spark and fuel (like does the neutral switch make it send less spark and fuel...??). But whatever, congrats!

supernaught
06-30-2009, 12:33 PM
Well, I tested for fuel from the injectors but I really had no way of telling if I was getting the right amount or if they were outputting at the right time. I do know that it was flooding badly - most likely why it wouldnt run before.

everlast
06-30-2009, 01:38 PM
If the parking switch was not connected you shouldn't have been getting spark. Maybe you just "hoped" you saw spark lol. ;)

Anyway, congrats. This is actually a great troubleshooting thread for the future, like EVERYTHING you can check to get your E30 running lol.

supernaught
06-30-2009, 02:07 PM
If the parking switch was not connected you shouldn't have been getting spark. Maybe you just "hoped" you saw spark lol. ;)

Anyway, congrats. This is actually a great troubleshooting thread for the future, like EVERYTHING you can check to get your E30 running lol.

The parking switch was connected(at C306) but the deal here was the single wire to tell the ECU. All other functions are dependent on the main relay working, and the wire from the switch to the relay was good. I did test earlier and the car would not crank when I had it in R(which I know is risky)

But ya, I looked at so much stuff my head was spinning. When the car actually fired up I nearly shit myself, but instead went straight for the beer fridge.

The only other important thing I never got to testing was the actual Fuel Pressure.

And that might still happen if I can't stop the injectors from dumping so much fuel in. The chip will help I'm sure.

supernaught
06-30-2009, 02:10 PM
BTW I would have had a HARD time doing a lot of these things without the Bentley. The Haynes is toilet paper in comparison. All those without it, get it.