[steak_knife]

Hi all,
As it says above, inj pulse is dropping off 3 seconds after start, eng stalls.
the eng is in a sierra with a std loom striped of non essentials like a/c idle up
ect. ( harness was not made by me )
List of ingredients the mod harness runs is.
1. air flow ( 3wire checked to ecu )
2.cas ( 3 wire checked to ecu )
3. injector ( 2wire checked ecu )
4. coolant temp ( 2 wire checked to ecu )
5. tps ( 4 wire checked to ecu )
6. start sig from ing switch ( checked at both ends 12v supply on crank )
7. 12v ing x2 ( from sierra harness to ecu ) not relayed witch i queried him about as it needs 12v & not a drop when cranking, i tested & on crank it had 12v.
8. ecu earth to eng block ( 2 checked to ecu & block earth as well )
9. igniter for coil ( 1 wire checked to ecu ) has spark 7& will run if carby cleaner is sprayed into intake.
10. ecu body earth ( 1 to body of car & 1 to eng block )

has he missed any thing or have any of you come across this problem before??
What if any gives the ecu a run signal? have studyed the Suzuki manual & found nothing on eng run sig.

any help would be greatly appreciated .


Steve

[canberramav]

I have this exact problem but the car will fire then stop straight away. I dont even get 3 seconds of run time. Its going into the shop on monday so ill post what they find to be the problem.

It may help you

[steak_knife]

Yes please!!

much to my disgust he cut the diagnostic plug off.


Steve

[unique_seek]

you running cold start???have you checked the injector pulse?or you asuming its not firring the injectors?I had a similar problem..was my injectors.The gti engine runs banked injecton with wasted spark.Check to see if you getting spark too..might be faulty "parts".was the engine running prior????

[steak_knife]

unique_seek wrote:

you running cold start???have you checked the injector pulse?or you asuming its not firring the injectors?I had a similar problem..was my injectors.The gti engine runs banked injecton with wasted spark.Check to see if you getting spark too..might be faulty "parts".was the engine running prior????

It runs a start signal & coolant temp but no apparent "cold start" but in saying that the ISC solenoid is Ecu controlled & receives a sig from coolant sen. Inj`s fire for around 3sec, spark is fine, run`s on carby cleaner.

Update!
Now that i have the harness away from the owner , I`ve striped & found 3 separate faults so far, 2 x high resistance, 1 x NO earth for ecu.
have the harness covering kitchen table, car on it`s way to me on a trailer as i type, should have it running within 30 mins of unloading it....

Cheer`s for the input so far.

Steve

[steak_knife]

i`m down to 1 wire now, ecm pin out B8, in 1 diagram (page 6e-14) it shows this pin is main relay earth, turn to page 6e-83 (suzuki workshop manual) b8 is the main relay switch.
Can anybody tell which it is??
Diag flow sheet read that it should have zero - two volts.

Cheer`s.

Steve.


P.s I still don`t have the car so I can`t test either way.

[unique_seek]

I would say its earth switching for the main relay??seems pointless for the ecu to provide an earth unless its switched?but it shouldn't have voltage?

[losfer]

use a paper clip and at the fuel pump relay jump the pink and the white with blue stripe. (as per 6e1-58)

maybe it isnt the injectors that are stopping to pulse , but the fuel pump is not pumping (unless you have tested the injectors with a noid light)

in the efi system , the fuel pump primes for three seconds on ignition on , the fuel pump then gets its "run" signal from the crank angle sensor.

the main relay gets its power from a white wire with red stripe. which coincidentally is the same colour wire that comes from the charge signal of the alternator!! shouldnt be your issue though considering it will run with an external fuel supply.

[losfer]

and yes forgot to add , b8 switches to earth as unique seek said.

[steak_knife]

losfer wrote:

use a paper clip and at the fuel pump relay jump the pink and the white with blue stripe. (as per 6e1-58)

maybe it isnt the injectors that are stopping to pulse , but the fuel pump is not pumping (unless you have tested the injectors with a noid light)

in the efi system , the fuel pump primes for three seconds on ignition on , the fuel pump then gets its "run" signal from the crank angle sensor.

the main relay gets its power from a white wire with red stripe. which coincidentally is the same colour wire that comes from the charge signal of the alternator!! shouldnt be your issue though considering it will run with an external fuel supply.

Thanx for the info,
Car has it`s own fuel relay ( which i will be changing to ecm controlled )

Checked inj pulse with noid light & it stops very soon (3sec) after crank stops.

Had a feeling "run" was from Cas.

White with red stripe is in car harness?? Not sure where he got his 12v feed yet.

B8, can i assume that i can run this to ground? Or dose the ecm switch ground to complete the circuit?
I`ve only just picked up the car so i`ll start work on it again tomorra.

Thanx again!!!
Steve

[steak_knife]

Do you guy`s run the speed sen?? (VSS) If so how? I`ve used a relay inline with a flasher before but can`t remember how i did it.



Cheer`s Steve

[canberramav]

Well the problem with mine was the wire a12 was supposed to be a negative pulse was connected to ignition.

Not sure if that will help you though

[steak_knife]

G`day canberramav,
I found the same thing in this harness, did`t fix the thing tho.
Took the cover of the ecu just to have a look & compared it to an ecu he had blown up & thay were very different. turns out there is 2 diffrent ecu & dizzy`s for the mrk 2`s, he was trying to use opposites.
Put the Ecu he had smoke escape from ( which is chipped for turbo ) & advanced the timing up & it runs ..


How`s your`s goin now??
He`s decided to bolt the turbo he has on, can`t wait to see it go.


Cheer`s
Steve

[canberramav]

Its running bu thats about it. Got a few things to tidy before its finished and also water leaks to attend to.

Running out of time as usual. I have a comp in 4 weeks

[RIKSTR]

canberramav wrote:

Its running bu thats about it. Got a few things to tidy before its finished and also water leaks to attend to.

Running out of time as usual. I have a comp in 4 weeks

Got some pics of it Justin? Can't wait to check it out.

[canberramav]

Hey Rick,

I dont have photos yet its now getting the wiring done at a friends house. Its a pretty hack install to tell the truth. I just cut a hole in the firewall for the dizzy as im too tight to fork out for the mazda cap and didnt want the hassles.

[RIKSTR]

HAHA Nice I guess as long as it runs