The V8 Owners Forum -

Just hoping that somone might be able to give some pointers with the 5.3 V8D engine running bad
A bit of a long story which ill try & keep short
After the first map all seemed OK, after next to no miles the idle was terrible and the afr gauges were showing lean at idle, Chris who did the mapping came over and did some adjustments and all seemed OK (he did ask if i had touched anything on the TB's etc, which i hadnt, i'm sure he didnt beleave me though) anyway a few Months later (again next to no miles) i sent it down to V8D for some other things which needed sorting, When i asked Rob what he thought of the map, the answer was crap, its running way to rich, (found this a bit odd tbh) anyway a new map on and the PAS pump was making a racket, so i sorted this when it was droped off, then moved it into another garage and parked up over the winter, battery disconected,
Went to start it up for the 1st time last Month, and it running crap!!! (very similar to the 1st time it played up, It seemed to start up on four cylinders, coughed and sputered onto six? i was thinking maybe a couple of plugs had get wet,
Anyway to try and make it simple...
1/If i pull the injector plug on No 8 and No 5 there isnt a dip with the revs
2/Two AFR gauges, one for each bank. No8 Bank, High 15's, No5 Bank Mid 15's
3/Nothing touched since mapping.
4/Next to no miles
5/Battery disconected over Winter.
6/ Cant see a prob with the linkage?

Any ideas, Sorry for the poor discription, its running a MS3 with JE inlet with ITB's

HELP
Steve

Hi
I can't point you at a quick fix but I can try and get you started.
Check all and clean all plugs and connections into the ECU, check the sensors are working in expected range.
Does the ECU have wide band lambda sensors fitted? if yes take it out and log the run, see what it thinks it is doing!
Do you have a base map off someone elses engine with a similar spec (like ITBs and a close ish cam, maybe a 4.6 or 5 litre, preferably a couple of them, print them out and the one in yours, do they look similar?
This should show up where to look.
Best regards
Mike

If you are running a pair of 4 post coil packs, 8 & 5 will be being driven off the same coil. If that's shagged then it'd account for both of them having no effect on the running of the engine.

I'd post to the MS forum - I assume you're using Extra code - and upload your MSQ. Some of the clever sods there can check for any 'funnies' just by glancing through it.

But have you hooked up to Tuner Studio? If things have changed due to it being powered down for so long (unlikely) it should give a difference report. Assuming you have already saved your MSQ to it when things were ok.

http://www.msextra.com/forums/index.php

Start with the Lambda sensors - given that two different people have looked at the figures and decided to adjust things in opposite directions.
(assuming both people both looked at your AFR readings and weren't using an external analyser)

Where are the lamdas located in the exhaust ? - are there any upstream leaks?
I assume they are wideband sensors, given you are stating specific AFR values (narrow bands are just guesswork)

Is the ECU running closed loop? - i.e reading the lambda and adjusting accordingly - ensure that its disabled and try to get a sensible reading at idle. Long lumpy cams with a lopey idle will make this difficult, raise the idle up enough to get a steady flowing reading. (Ensure that other MS feature that adjusts the actual VE table, autotune? isn't moving things around either)

With a stable reading and closed loop off, try swapping the sensors over and ensure that they give close if not identical readings.

By elimination, this should give you some confidence in the readings to move forwards.

Thanks for the replies.....
Ill check some of the things mentioned tomorrow.
Just had a horrible thought though, When it got started up (firing on 6?) it was a rush job having to get it on a transporter, so it was driven up on 6, when it got to its destination it was unloaded on 6 and the same coming back i did take a couple of plugs out, but wondering if its a poss that it really flooded up on a couple of cylinders & even with the new plugs in it hasn’t cleared itself????? Do you reckon it’s a poss? Just thinking starting at the basics.
I used a airflow metre on the TB's Today and they seem fairly well balanced, so i suppose that eliminates the linkages been out, I un plugged the HT lead from the No8 coil and that was sparking well, so it looks like the coilpack is OK
The AFR gauges are not linked to the ECU.

I agree with scudderfish, You should check the coil feeding 8 & 5.
If you have a plug down on both banks then the Fuel air gauge will read lean and will not show the actual mixture ratio.

Regards Denis

Just a quick question before my batt dies on the laptop. What are the diference reports on the MS3 when pluged in? connected it up tinight and its stacked with Yellow diferences

That is where the config on the ECU differs with the last saved version on your laptop. You have to decide which is more correct.

Hi,
email me the msq file and a datalog of it idling and I will take a look

(phil(at)extraefi.co.uk)

I suspect the ITBs though, in my experience of them they tend to leak, have you balanced them all and set them up using a flow meter?
If so then are they still balanced?
thanks
Phil

If the O2 sensors ain't linked to the MS, it won't be running closed loop, so unless you've altered things manually, TS shouldn't be showing any differences, if you're certain you've loaded the correct MSQ file to TS.
Might be worth posting a screenshot of the difference report.

Check all your earth connections are good and not corroded.

Check both physically and electrically

daxtojeiro wrote:Hi,
email me the msq file and a datalog of it idling and I will take a look

(phil(at)extraefi.co.uk)

I suspect the ITBs though, in my experience of them they tend to leak, have you balanced them all and set them up using a flow meter?
If so then are they still balanced?
thanks
Phil

Thanks for the advice Phil, Ill try & see what i can do over the weekend, Rob at V8D seems to think a poss could be the injector drivers with it been on 5 & 8 and suggested sending the ecu over to you for checking? i would guess if i can get my head around how to get the msq file and the datalog that would answer if its a driver fault?
It seems to be sparking OK on5 8
I have the Tuner Studio & Mega Log viewer on the laptop but never used it
Steve

DaveEFI wrote:If the O2 sensors ain't linked to the MS, it won't be running closed loop, so unless you've altered things manually, TS shouldn't be showing any differences, if you're certain you've loaded the correct MSQ file to TS.
Might be worth posting a screenshot of the difference report.

Ill give it a try Dave, Really US with this type of stuff, i think i stumbled on the diferencereport by accident

As above really, can anyone talk me through how to datalog and get the msq file. i have both Tuner Studio & Mega Log viewer on the laptop but never used them USB lead is connected to the ecu so its easy to connect up..........
Thanks
Steve