injectors flooding on 88 tsi

[rcm]

Me too vbrad511.You think it goes in one direction and then it does a 180 to something else.Most of the

time it is very hard to correct someone else mistake.The general principals dont always apply to

these cars.I know i had to have help the first time i was a member and the second time now for

eight years.Although i havent had one for five years you have to reprogram your thinking and refresh.

But i do appreciate all the input because there is something i am not seeing right off although

the timing today was certaintly a problem that needed corrected.I did go over the valve adjustment

since i was already there and of course they where too tight cold.So i set them at .006 and .010 to start

with and probably have to go back once running right and warm.But i do know two intakes i couldnt get

.003 in there.

[Edde]

What is it doing now? I know it's worse but what does that mean exactly?

 

If it were mine I would do my tshooting from this point using stock injectors not those delphi's. Are the stock - one black and one blue/green? The one with the small spray orifice must be primary regardless of the color. I know it may be a silly detail but if by chance one is not obviously smaller than the other that's a problem. If the blue or larger one is hooked up as primary it'll never run right. It has mech valves so does it have slip rockers or rollers?

[rcm]

Well i thought the delphi where opposite but checked twice on that,the original ones,the used stock where both black and green.Green towards the vc and the black towards driver side.Whats unusual everything i have done has not really

changed anything.One constant i have seen is all set of injectors are doing the same thing as dumping fuel

to me and flooding.Cleaned fuel rail,fuel filter,3 sets of injectors.The only thing i have not checked is

fuel pressure because of it not running at idle to check.I am not sure i can check just by jump the fuel pump?

My question i had was if the pressure is low would it make them dump fuel instead of a fine spray pattern.I really

havent looked to see if it had been changed i was thinking the po thought it was.The mechanical rockers are sliders.

To answer question of running worse the number one plug was fouled out so it was running on 3 cylinders after i turned

dist all the way cc but that was changing the firing order one cylinder to start.But i did mention in previous post

that i could pinch off the fuel line and it would run so thats why it has a new fpr.But by pinching it off

that may have incresed pressure to the injector enough to atomize.

[Edde]

I can't imagine it could hurt as a test to see fuel pressure just with the pump cooking. It would have to read some number and it could be instructive . At this point anything like that is worth a try. Could also run a separate return line to a bucket and see what happens - obviously being concious of the risk of fire. I guess there is NO chance the injector clips are wired backwards causing the secondary to spray on crank?

 

As for low fp causing the dumping - I haven't a clue. On the one hand it seems reasonable, on the other hand not. Is there roughly 3.5 ohms between the terminals on the injectors themselves?

 

So now with all cam and dist timing verified and good plugs it starts but doesn't stay running? Won't stay running with some pedal tweaking? If it's really pouring fuel and you can keep it running briefly I would expect you'd see black or at least really gray smoke.

[rcm]

Well i havent tried since the bad plug but before the timing it would stay running as long as the rpms

were up.The secondary injector unplugged so thats not a factor yet.I have already ran another return line before and no change to insure the line wasnt stopped up.I have checked wiring with the fsm and color coded right to each injector.

Even swapped just to see but no change.When it does run and pull plugs they are black.I have changed oil twice because

of gas in it.I thought i would pull access panel and look at the fuel pump,hose routing etc.I am also going

to check ground impulse with analog meter to see if it is moving or just staying ground constant while cranking.

[rcm]

Well ok...put back together.Checked the primary injector clip with analog meter.Turn key on wait a few seconds

and it goes to ground.Then in cranking mode the meter moves one or two times then just stays level.Tried the secondary and it doesnt do anything at all even if the accelerator is wide open.Which i think is correct since not running?Pulled fuel

rail and the screens are there and look new and very clean.Inspected the injectors for correct size ,the small

orfice is on the drivers and bigger orfice is on the vc side.I started it first by carb cleaner in the fpr vacuum port.

Started and ran as i was feeding it spray.Hooked primary injector up started and ran as long as i had it above 2500

rpms.Then i could turn it up over 4k rpms and it cleared out and ran smooth,turbo spooled up good.Let it back down

below 3k rpms and it would stumble.So it would run on the primary only and that tells me how much fuel is dumping.

I know some are going to say injectors are dirty even though new but all three sets did the same thing.So is the

computer holding ground constant or is the pulse so fast it doesnt register on the meter?

[Indiana]

Well ok...put back together.Checked the primary injector clip with analog meter.Turn key on wait a few seconds

and it goes to ground.Then in cranking mode the meter moves one or two times then just stays level.

 

Turn the key on and nothing should happen. When cranking it only grounds when there is an ignition pulse. No the secondary won't do anything.

 

On your ignition coil, what wires are on it and their colors and where do they go to? Any of those been cut or spiced or is anything added?

 

Something is wired wrong and causing that driver wire to the primary to get a ground other than the ECU or the ECU is fried. Even a screwed up ignition pulse might cause it but I doubt it. I can't say because I've never seen it or tried that.

 

When someone changed clips at some point they may have touched the power to the driver wires and had the key turned on or they didn't insulate their connections and they touched.

 

I think your ECU is fried. You said it had been replaced, the ones I've seen that were rebuilt the case was painted black. Then again it may have been replaced because of screwed up wires on the coil. There's the wire to the ECU from the - terminal, the + is the ignition switch, there's a metal resistor box with two wires from it, black and white and that's in line from the - and plugs into the harness it leads back to the dash tach and a little plastic plastic box that's a noise filter you don't need it is under the + terminal and connects to a ground pigtail on the intake manifold. I don't know what would happen if that resistor was fried.

[rcm]

ok...Black with white stripe to positive side of coil and blue wire from positive to small black

box.Black wire from small black box to negative side of coil.Blue with white stripe to negative side of coil.

Black wire from negative side of coil to small silver box.White wire from silver box back to wiring harness.

The yellow with white stripe and black with white stripe going behing fusible box where the relays are where splice

with a toggle switch for something.I removed all that junk and repliced wires .I was thinking something

maybe wired off of coil was wrong or something telling ecu ground constant.

[Indiana]

blue wire from positive to small black

box.Black wire from small black box to negative side of coil.

 

There's the problem, that black wire from that noise filter goes to the intake manifold or just remove it. Its a noise filter. It pluged in to a pigtail that came from under the mounting bolts for the EGR valve and usually it dangles and breaks off.

[rcm]

Ok.Disconnect the noise filter wire off negative side of coil.Now with the key off the driver wire is showing resistance.

Turn key on and the power side is 12 volts and the driver wire is showing o.59 volts.Does that mean the ecu is junk or

is that little silver resistor bad?The secondary is showing correct.Power on one side with key on and driver shows

no resistance.

[The Rabbit1]

Ok.Disconnect the noise filter wire off negative side of coil.Now with the key off the driver wire is showing resistance.

Turn key on and the power side is 12 volts and the driver wire is showing o.59 volts.Does that mean the ecu is junk or

is that little silver resistor bad?The secondary is showing correct.Power on one side with key on and driver shows

no resistance.

getting there, stick with it. Question for Indy, if he was to disconnect the ecu now, he should lose all continuity to that injector correct? It would show if the wiring goes only to the ECU if I'm correct.

[rcm]

I did unplug the ecu and the wire had no ground so there is no splice off of it.Plug it back in

and it has ground.Turn key on and the driver shows .59 volts.CRAZY.

[Indiana]

Got another ECU?

[Edde]

Have you posted for an ECU yet?

[rcm]

Yeah i posted yesterday and have one coming from gtxthunder.Hopefully that repairs that problem.

[Shelby]

one more thing to do,, unplug the ecu connector and remove the pri inj ground signal wire from the connector , this is pin number #60 small inj

pin locations can be found on page 14-11

 

plug ecu back up and retest the pri inj wire for a ground signal , if you recive any resistance or ground signal at all, the problem is in the wireing harness .

 

now probe the ecu at pin 60 with volt ohm meter , key on ,if you recive any reading whats so ever the ecu is bad , there should be no reading on that wire terminal

 

if the problem is in the harness you can bypass the harness with suitable length of 18ga wire from neg terminal of inj clip to ecu pin 60, see if the inj now is spraying without engine runing

 

small note about reading inj run signals,, a good digital volt meter will show a reading of 1-2.5 volts with engine ruing and rpms up to about 2500 rpms,,

above that the ecu should kill the pri inj ground signal and start the sec inj spraying (the exact rpm can very ( 2500 -3000 ) depending on many factors such as air flow tps etc ,,some meters will not show a duty cycle, and thats what your actualy reading when reading the inj voltage with a runing engine

 

both the pri and sec inj operate in an on-off pattern, the amount of fuel being deliver'd depends on the ON time

[patra_is_here]

i've only read the last page of this thread. but i'm gonna say it's the injector resistor, just because i like to guess at things.

[rcm]

Well the resistor is showing resistance like it should,with key on it has 12 volts.The driver wire is the one

that has resistance constant and with key on shows low voltage.But a good guess.Try a computer swap first and

go from there.Then may have to pull pin out of harness and check by shelby suggestion.

[Indiana]

Digital meters mess with you. Are you using an analog meter?

[rcm]

analog meter that i have had for 25 years.I trust it more than these newer ones.I do have a cheaper digital

for 12 volt checks.

[Shelby]

analog meter that i have had for 25 years.I trust it more than these newer ones.I do have a cheaper digital

for 12 volt checks.

 

 

i'd strongly sugest you do my tests on the old ecu,,a short'd inj wire could burn up a good ecu

[Edde]

i'd strongly sugest you do my tests on the old ecu,,a short'd inj wire could burn up a good ecu

 

Maybe next time you can show up prior to page 9 http://www.starquestclub.com/forum/public/style_emoticons/default/tongue.gif

[rcm]

Ok....Did shelby test on pin 60.Disconnect from harness and there is no continuity at primary injector.

Harness plugged into computer with key on pin 60 shows low voltage of .50 or so.

Edited January 21, 2011 by rcm

[Shelby]

Ok....Did shelby test on pin 60.Disconnect from harness and there is no continuity at primary injector.

Harness plugged into computer with key on pin 60 shows low voltage of .50 or so.

 

 

your testing for a ground so a resistance reading is what you need,, but if your powering the meter at a power source and it's reading .50 volts it's deff seeing a ground

now do the same test with sec inj wire , pin 62 ,,do not do your test thru the inj,,use the ground side of the inj clip

 

most early ecu systems use'd a single driver for 2 injs,, not sure if mits did that or not but if they did that could posibly pulse both injs , but even if they use'd 2 drivers all it would take is for some one to use a 12 volt test lamp on the ecu inj grounds with the key on ,that will blow the inj drive transistors

almost instantly

[rcm]

Resistance is what i meant.No meter movement at all.But with key on checking at pin location it pegs the

meter.So i then put the dial on dc volts 5 and it reads .50 volt.I suspect that so many people have

worked on this car ,and all the splices etc it doesnt suprise me that it is fried.Should have another ecu today.

I thought to do the same test on the other ecu to see if same results before plugging the #60 pin back in.