Hot Start Issue

[Hanaldo]

I'm not sure if my problem is mixtures though. When we (room42 and myself) checked it last week, everything was normal. Changing things didnt affect anything. The only thing that made a difference was when my battery went flat from cranking, we hooked it up to his battery and then it started a lot better. So seeing as this all started when I relocated my battery to my boot, it's plausible that my battery simply isn't up to the task.

Having said that, when I got somebody to jumpstart me today, it still didn't want to start.

[SargeRX8]

This is how i got it started when I got stick somewhere before I fixed the problem

Take out fuel pump fuse, crank car, it should go to start but cough and die, then put the fuse back in and restart the car...should start

This is what I done when I couldn't get my car to start. Flooded the engine with fuel so it was NEVER going to start so let it dry pump to blow the fuel out then wired it back up and it started.

Jez tuned my car and when he did he said that my injector MS was set to 0% on my pfc and that this *could* cause issues with starting/idling I think. With that said, since my fuel mix was sorted(I was rich rich rich), I have not had any starting issues. I know the experience of getting broken down far from home. My dads cars starter motor failed on me when I was at penrith, same car failed on me when I was at work, this car wouldn't start when I was out with my lady(rich tune wet the f**k out of my sparks and pistons). Wet is good, too wet is too much fuel which can foul plugs. Have you tried new plugs? If its not tune related, it must be hardware related and the plugs are what I would look at first. Failed starts will generally keep squirting fuel into the engine I believe and if you don't get it to start it could foul shit up.

[SiR_RB]

when mine had hot start issues i changed the coolant and intake temp sensor and still didnt fix anything, then changed to a new super dooper battery and didnt do nothing

i think its got something to do with mixtures?

[bubba]

I'm not sure if my problem is mixtures though. When we (room42 and myself) checked it last week, everything was normal. Changing things didnt affect anything. The only thing that made a difference was when my battery went flat from cranking, we hooked it up to his battery and then it started a lot better. So seeing as this all started when I relocated my battery to my boot, it's plausible that my battery simply isn't up to the task.

Having said that, when I got somebody to jumpstart me today, it still didn't want to start.

$120 for a 550CCA from Caterpiller (Westrac)

[Hanaldo]

This is what I done when I couldn't get my car to start. Flooded the engine with fuel so it was NEVER going to start so let it dry pump to blow the fuel out then wired it back up and it started.

Jez tuned my car and when he did he said that my injector MS was set to 0% on my pfc and that this *could* cause issues with starting/idling I think. With that said, since my fuel mix was sorted(I was rich rich rich), I have not had any starting issues. I know the experience of getting broken down far from home. My dads cars starter motor failed on me when I was at penrith, same car failed on me when I was at work, this car wouldn't start when I was out with my lady(rich tune wet the f**k out of my sparks and pistons). Wet is good, too wet is too much fuel which can foul plugs. Have you tried new plugs? If its not tune related, it must be hardware related and the plugs are what I would look at first. Failed starts will generally keep squirting fuel into the engine I believe and if you don't get it to start it could foul shit up.

Yeh gonna go pull it all apart now. The spark plugs are pretty much new though, have done maybe 6000kms with them. I pulled them out about 2 months ago when I did my comp test and they were perfect.

$120 for a 550CCA from Caterpiller (Westrac)

Yeh I just went to Battery World, they let me try a huge 720cca battery... Changed nothing. So it's not the battery

[rob82]

Cranking ignition timing at 10degree will be fine. 45degree's is just rediculous and on the wrong ECU could do damage. Have never seen an engine crank any better with 45degree timing.

I would first check that you are getting good spark at crank. What injectors, fuel pressure pressure reg and spark plugs? What plug gap? On some ECU's there is a min rpm to turn the injectors on but its usually below 150rpm. From the video it sounds like your cranking higher than that though.

You need to modify your craning ms at the temp your having issues at.

[Hanaldo]

Cranking ignition timing at 10degree will be fine. 45degree's is just rediculous and on the wrong ECU could do damage. Have never seen an engine crank any better with 45degree timing.

I would first check that you are getting good spark at crank. What injectors, fuel pressure pressure reg and spark plugs? What plug gap? On some ECU's there is a min rpm to turn the injectors on but its usually below 150rpm. From the video it sounds like your cranking higher than that though.

You need to modify your craning ms at the temp your having issues at.

Yeh that's where it's set, we tried increasing it to 15 degrees but it didn't make any difference. If I'm not getting good spark, wouldn't that still occur when the car is cold? This is definitely a warm start issue. I'll check spark regardless.

We did try changing the cranking ms, but got a little confused with NIStune. In the enrichment tables, there are 6 different tables that we couldn't work out the difference between: Crank Enrich, Crank Enrich Offset, Crank Enrich Offset 1, Crank Enrich Offset 2, Crank Enrich Offset 3, and Crank Enrich Offset 4. We tried modifying them one by one but nothing made a difference to starting. Not sure if they all need to be modified? In any case, the AFR's seemed to be fine during cranking.

I've got the spark plugs out now just checking everything, if I can't figure anything out then I'll have to get in contact with my tuner and see if he can fit me in.

Edited September 5, 2011 by Hanaldo

[rob82]

Yeh that's where it's set, we tried increasing it to 15 degrees but it didn't make any difference. If I'm not getting good spark, wouldn't that still occur when the car is cold? This is definitely a warm start issue. I'll check spark regardless.

We did try changing the cranking ms, but got a little confused with NIStune. In the enrichment tables, there are 6 different tables that we couldn't work out the difference between: Crank Enrich, Crank Enrich Offset, Crank Enrich Offset 1, Crank Enrich Offset 2, Crank Enrich Offset 3, and Crank Enrich Offset 4. We tried modifying them one by one but nothing made a difference to starting. Not sure if they all need to be modified? In any case, the AFR's seemed to be fine during cranking.

I've got the spark plugs out now just checking everything, if I can't figure anything out then I'll have to get in contact with my tuner and see if he can fit me in.

Dont even look at your AFR gauge at crank as there will not be enough airflow to get any sort of valid reading. Could you see any change in ms during crank when modifing those tables? I would be trying big changes to the Crank Enrich and see if it makes any difference.

What injectors?

[Hanaldo]

What injectors?

Ah my bad, forgot to answer. They are Power Enterprise 650cc's.

As for the others, fuel pressure reg is stock and spark plugs are Iridiums gapped to 0.8mm. Will try altering the Crank Enrich table when I've got all the plugs back in.

[GTRNUR]

Dont even look at your AFR gauge at crank as there will not be enough airflow to get any sort of valid reading.

Don't take this the wrong way Rob but you seem to have some have some theories that conflict with a lot of what I have said. Not that I mind because everyone is entitled to their own opinion. It is also easy to be misunderstood or taken out of context when every minute detail of an explanation is not mentioned, or when only sections of a thread (and not the whole contents) are read.

I'll say this about my AFR meter comment. If the car is hot and is started, and the exhaust temp is higher than about 300 degrees (as it would be when its hot), and then it is stopped and then immediatly re-started again you CAN use AFR meter information to determine if cranking and post start enrichment values are close. But it takes experience and an understanding of the engine you are tuning to know what is needed. You rely on your ears and the tacho just as much as what you see on the AFR meter.

I admit that I was in stunned disbelief when I was told of the 45 degrees cranking ignition values in RB's as well. That particular piece of wisdom was from an EFI specialist (and trainer of other well known Australian tuners). I was then told that piece of knoweledge came from scoping out a standard car, as this is something he commonly does with development of new EFI systems. The man is an encyclopedia of all engine knowledge and has tuned virtualy every make of production engine in standard and radically modified forms as well as motorsport up to F1 level.

I never post information that I am not 100% sure of. I draw on my own personal experiences and also from knowledge attained from the formal EFI tuning training I have undergone. There are always circumstances where something is 100% true in some situations and 100% incorrect in other situations. As I have said, not all or maybe even none of what I have suggested may relate to a Nistune as they are not one of the ECU's I have ever tuned. But the basics are still correct, so with a timing light, AFR meter, your nose, ears and eyes it does still apply. Engines are still engines. Fuel, air, spark, bang.

[rob82]

Don't take this the wrong way Rob but you seem to have some have some theories that conflict with a lot of what I have said. Not that I mind because everyone is entitled to their own opinion. It is also easy to be misunderstood or taken out of context when every minute detail of an explanation is not mentioned, or when only sections of a thread (and not the whole contents) are read.

I'll say this about my AFR meter comment. If the car is hot and is started, and the exhaust temp is higher than about 300 degrees (as it would be when its hot), and then it is stopped and then immediatly re-started again you CAN use AFR meter information to determine if cranking and post start enrichment values are close. But it takes experience and an understanding of the engine you are tuning to know what is needed. You rely on your ears and the tacho just as much as what you see on the AFR meter.

I admit that I was in stunned disbelief when I was told of the 45 degrees cranking ignition values in RB's as well. That particular piece of wisdom was from an EFI specialist (and trainer of other well known Australian tuners). I was then told that piece of knoweledge came from scoping out a standard car, as this is something he commonly does with development of new EFI systems. The man is an encyclopedia of all engine knowledge and has tuned virtualy every make of production engine in standard and radically modified forms as well as motorsport up to F1 level.

I never post information that I am not 100% sure of. I draw on my own personal experiences and also from knowledge attained from the formal EFI tuning training I have undergone. There are always circumstances where something is 100% true in some situations and 100% incorrect in other situations. As I have said, not all or maybe even none of what I have suggested may relate to a Nistune as they are not one of the ECU's I have ever tuned. But the basics are still correct, so with a timing light, AFR meter, your nose, ears and eyes it does still apply. Engines are still engines. Fuel, air, spark, bang.

Look I totally agree with you on being able to measure post start enrichment ARF's but cranking AFR is just too hard read as there will events where there is incomplete combustion or even raw fuel entering the exhuast. Plus your airflow rate is just to small. When it comes to tuning initial start - you just need to give the enigne what it wants.

I also take what I get told with a grain of salt especially when it varies greatly from normality. You may find that there could have been syncing errors causing incorrect timing at crank which may have led to 45degrees timing being the magic number. Most ecu's have difficulty with cranking ignition wandering all over the place.

I tend to trust factory ECU's to have both timing and fuelling properly sorted but I've seen plenty of aftermarket ecu's struggle even the big one's (motec). I've disassembled many ECU's and the norm is generally from -10 to 15degree's for crank.

Being in Cairns I take it you are refering to Ray Hall?

[Room42]

Well its odd that the new 7xxcca battery didn't help seeing as jumping made a good difference the other day. It was probably cos your battery was flat. My car is still playing up a bit like yours. I have changed my 50 and 80 celcius crank inj ms to 35 and it seems to help. I haven't had a long time to test this tho. Something I have noticed with both of our cars is that when they are hot and turned off and started within a short time they both start ok. When they are left off for a little while they both crank for too long. It seems to me that we may be getting a bad initial spray pattern from our injectors to get it started. Still, we only need compression (we got it,didn't change), fuel (problem?) and spark (we got it,didn't change) to make it go. I have 9xxcc injectors and you have 650cc injectors. My car started fine before I swapped the injectors. I have changed the latency on the new injectors a lot, up and down to minor effect. The injector size percentage on the pfc is the equivalent of the k constant on the nistune and it only got so good then it wouldn't get perfect. We didn't touch the k constant on yours but I changed the latency a lot to small effect on starting. I reckon one of us should try our stock injectors again and see if that helps out. I could only get mine "so good" with the new injectors then that was it regardless of everything I have tried, and I have tried everything I know about starting a car except the afm scaling down low. I don't think that will affect anything as changing the inj cms would alter that anyway. I have a set of 370cc stockers in my shed and I'm very tempted to put them back in to see what happens. I also have a stock afm so that can be tried out as well. At the end of the day your car is not starting acceptably at all. Sure a few seconds of cranking is ok but draining the battery from cranking is no good at all. I'm happy to help you sort this out sometime but probably not till next week as I'm getting married on Friday and the inlaws are over tomorrow for a week. After next Tuesday as is fine.

Can anyone see a common thread here with the lack of starting??

P.s. Initial timing on Hanaldos and my car has been changed significantly. No difference. Up to 50 degrees on mine made it worse.

Edit: Hanaldos car showed 21.9:1 on the afr gauge while cranking and normal while idling. No cranking ms change wold make a difference.

Edited September 5, 2011 by Room42

[Lithium]

Don't take this the wrong way Rob but you seem to have some have some theories that conflict with a lot of what I have said. Not that I mind because everyone is entitled to their own opinion. It is also easy to be misunderstood or taken out of context when every minute detail of an explanation is not mentioned, or when only sections of a thread (and not the whole contents) are read.

I admit that I was in stunned disbelief when I was told of the 45 degrees cranking ignition values in RB's as well. That particular piece of wisdom was from an EFI specialist (and trainer of other well known Australian tuners). I was then told that piece of knoweledge came from scoping out a standard car, as this is something he commonly does with development of new EFI systems. The man is an encyclopedia of all engine knowledge and has tuned virtualy every make of production engine in standard and radically modified forms as well as motorsport up to F1 level.

I never post information that I am not 100% sure of.

I'm on a neverending mission to improve my understanding of tuning, the behaviour of engines and the way the two relate but I can't get my head around how 45deg of cranking advance would be good. Without your statement, I'd expect the combustion to be fighting the cranking, if not actually inducing kick back.

There is no way I'd try this myself just on the merit of an unexplained statement by a random on a forum, and in all honesty I've seen too much crap spun qualified by nothing more than the "I heard this from an all wise .... guru" to take it on board. I do however always keep an open mind (the more you know, the more you realise you don't...) and given you are 100% of this, please share the wisdom - what is advancing the timing that much at cranking doing to assist the start, and how is it not going to be bad?

[Hanaldo]

Well its odd that the new 7xxcca battery didn't help seeing as jumping made a good difference the other day. It was probably cos your battery was flat. My car is still playing up a bit like yours. I have changed my 50 and 80 celcius crank inj ms to 35 and it seems to help. I haven't had a long time to test this tho. Something I have noticed with both of our cars is that when they are hot and turned off and started within a short time they both start ok. When they are left off for a little while they both crank for too long. It seems to me that we may be getting a bad initial spray pattern from our injectors to get it started. Still, we only need compression (we got it,didn't change), fuel (problem?) and spark (we got it,didn't change) to make it go. I have 9xxcc injectors and you have 650cc injectors. My car started fine before I swapped the injectors. I have changed the latency on the new injectors a lot, up and down to minor effect. The injector size percentage on the pfc is the equivalent of the k constant on the nistune and it only got so good then it wouldn't get perfect. We didn't touch the k constant on yours but I changed the latency a lot to small effect on starting. I reckon one of us should try our stock injectors again and see if that helps out. I could only get mine "so good" with the new injectors then that was it regardless of everything I have tried, and I have tried everything I know about starting a car except the afm scaling down low. I don't think that will affect anything as changing the inj cms would alter that anyway. I have a set of 370cc stockers in my shed and I'm very tempted to put them back in to see what happens. I also have a stock afm so that can be tried out as well. At the end of the day your car is not starting acceptably at all. Sure a few seconds of cranking is ok but draining the battery from cranking is no good at all. I'm happy to help you sort this out sometime but probably not till next week as I'm getting married on Friday and the inlaws are over tomorrow for a week. After next Tuesday as is fine.

Can anyone see a common thread here with the lack of starting??

P.s. Initial timing on Hanaldos and my car has been changed significantly. No difference. Up to 50 degrees on mine made it worse.

Edit: Hanaldos car showed 21.9:1 on the afr gauge while cranking and normal while idling. No cranking ms change wold make a difference.

Yeh same story with me, my car started well before the injector swap. But then it was never such a huge problem before the battery relocation. I had thought that perhaps I was getting too much voltage drop over the length of cable, given when I was cranking it yesterday my battery was going from 12.5v straight down to about 7.8v. Also with the key switched to accessories, my turbo timer reads 11.4v when the battery reads 12.5v. But the people at Battery World said my battery probably is a bit small for my application, but it's still turning the starter motor fine. If the problem was caused by the battery being too small then cranking would be slow.

Without having much experience in the matter, I was confused about how having a lean ms at cranking would cause problems like this? Because surely when you are cranking, fuel is being injected. Even if it is a small amount of fuel, surely it would inject enough to start the motor before you cranked the battery flat? Which made me think that perhaps there is too much fuel getting in, even though there is no enrichment value set? I don't know. I'm gonna phone my tuner after lunch today, see if he can fit me in. It's getting to the stage where I don't want to drive my car because I don't know if I'll be able to get home again. Not too mention the fact that I'm wearing everything out by cranking it so much.

[bubba]

7.8v cranking is pretty low isn't it?

Could the starter be dying? and drawing a lot more current than it needs? to the detriment of other systems?

[Hanaldo]

7.8v cranking is pretty low isn't it?

Could the starter be dying? and drawing a lot more current than it needs? to the detriment of other systems?

It is, it's very low. I will need a new battery in the future. But using a bigger battery didn't affect the starting issue.

The starter doesn't click or make any noises, it seems to behave as it should. Also it's fine when cold, if it were the starter then surely temperature wouldn't have much effect?

[bubba]

The temperature could be affecting a connection to the point where when it is hot it's draining excessive current (bad earth? etc).

A bigger/newer battery won't help in that case.

IMO, *something* is drawing way too much current when hot and cranking, to the point where the fuel pump doesn't have enough voltage to maintain pressure..

Does it cough and fart at all when it's doing it? or just spins over without even trying to fire?

[rob82]

7.8V is low - have you run two cables to the front or just earthed through the chassis? Is there a difference in voltage at the battery compared to the ECM once the car is running? Injectors will struggle to open at 7.8Volts.

Try a jumper lead from the battery negative to the engine block.

Edited September 6, 2011 by rob82

[Hanaldo]

The temperature could be affecting a connection to the point where when it is hot it's draining excessive current (bad earth? etc).

A bigger/newer battery won't help in that case.

IMO, *something* is drawing way too much current when hot and cranking, to the point where the fuel pump doesn't have enough voltage to maintain pressure..

Does it cough and fart at all when it's doing it? or just spins over without even trying to fire?

Have checked the fuel pressure, it seems fine... It's definitely getting fuel.

If it coughs then it usually starts soon after. If you watch the video I posted earlier then that is pretty much what it does. The first time I tried starting it, it just cranked without even trying to fire. The second time it cranked for awhile and then eventually started. Yesterday when I got stuck for 3 hours () it just cranked without even trying to fire. Eventually drained the battery dead and I just gave up trying until water temps were back down to 40ish.

[Hanaldo]

7.8V is low - have you run two cables to the front or just earthed through the chassis? Is there a difference in voltage at the battery compared to the ECM once the car is running? Injectors will struggle to open at 7.8Volts.

Try a jumper lead from the battery negative to the engine block.

Just earthed the battery to the chassis... The cable we used was so big there wouldn't be space to run a second one. Left the standard earths as they were except for the battery which we re-earthed at the back. I've checked those, they seem ok? Thing is, that voltage may have already been because they battery was already going flat. Once it started I didn't check the cranking voltage again because I didn't want to turn the car off lol. Once it's running I'm not sure, I'll check.