SR T28 and tuning questions.

[beatd]

Hey guys,

First off my setup is: Stock KA24DESR T28370CCwalbro 255N62 Maf

I was in the process of tuning my car yesterday and my tuner who is local was having problems with my car.

He told me the car would run rich at idle or cruise and run lean once the car hits boost. He said he the car would not respond to any changes he made to the ecu. Could this be a grounding issue? or bad ecu issue?

However the main problem is at full throttle the car would not rev past 4800 rpms. What could be causing this?

I also have a SAFC installed while he was tuning the car. Next time i go there should i uninstall the SAFC? Because i think its causing problems with the ecu.

Any suggestions would be awesome because we are going to try again on next weekend if weather permits and i want ideas to see what could be causing my problems.

[Ekinchheng]

You check out your maf reading? Is it wired correctly? Check for loose connection or maybe its a faulty maf. Who's is this tuner you speak of? I might be in need of tuning later on the road when I go ka-t and was wondering how much he charge?

[red ka-t]

Is it building boost? Is the S-afc wired in right? Have you checked for boost leaks?

[Chris28]

What does you base tune consist of? Are you running solely the SAFC or do you have a rom tune to support the 370cc injectors. If it's a rom tune it should be fine and the SAFC would make for little adjustments.

What input is the ECU not responding to? Is your tuner dialing in the SAFC and it's not responding, or is he using some other method of tuning?

[WDRacing]

Need your entire setup man...to include the management stuff.

[Ken Park]

Unless something has changed, Im positive that you cant make adjustments for a different MAF with an SAFC. This could be your problem. You also cant make timing adjustments with the SAFC, which you need to. I don't understand why people bother with them when you can get a tuned ECU for not much more.

[beatd]

Everything in my car is fine now except cold starting. I don't know what fixed it but we took off the safc, and my ecu had a jumper that needed to me moved so that the ecu will read from the daughterboard. my car feels awesome and i love it.

however my cold start issue is still there. For example when i try to start it after sitting over night it would have a hard time. I would have to keep pressing the gas pedal and cranking it to get it to work.

Could it be because i moved my battery to the trunk and used 4gauge positive wire? should i move my battery back to the front with a smaller one? or should i use 0 or 00 gauge wire for the positive wire?

[Chris28]

Try turning the key just to the on position so you let the fuel pump prime and get fuel to the injectors.

Also, when I put my new injectors in I forgot to lube the o-rings up with vaseline. This caused the o-rings to tear and my injectors were leaking. After I replaced the rings and made sure the injectors were sealed it was much easier to start, like 2-3 turns of the engine vs the 20-30 that it was taking before.

[beatd]

Try turning the key just to the on position so you let the fuel pump prime and get fuel to the injectors.

Also, when I put my new injectors in I forgot to lube the o-rings up with vaseline. This caused the o-rings to tear and my injectors were leaking. After I replaced the rings and made sure the injectors were sealed it was much easier to start, like 2-3 turns of the engine vs the 20-30 that it was taking before.

i let my car prime everytime i start the car. also i put alot of vaseline when i replaced the injectors so that couldn't be it. i'm thinking either going to a small battery or changing the wire to 0 gauge and hopefully it would help. any other suggestions are more than welcome.

[DevilMB3017]

What tuning did you end up with in the end?

It's possible your just not tuned well for a cold start.

If you're still pulling timing above 4.2k or so, it's also possible your water temp sensor is no good. It's pretty common and causes a lot of weird issues with KA's.

I've had both 4ga and now currently 0ga wiring and haven't had problems with either. It's also possible you're battery just isn't that strong anymore. What type of battery? How old is it?

[beatd]

What tuning did you end up with in the end?

It's possible your just not tuned well for a cold start.

If you're still pulling timing above 4.2k or so, it's also possible your water temp sensor is no good. It's pretty common and causes a lot of weird issues with KA's.

I've had both 4ga and now currently 0ga wiring and haven't had problems with either. It's also possible you're battery just isn't that strong anymore. What type of battery? How old is it?

My tuner made a special map for me and it runs perfect except the cold start. he told me it could be the wiring because its 4g or my starter going bad. I put a brand new coolant temp censor for the ecu already. the battery is also new its the duralast gold top from autozone. i also cleaned the iacv.

[DevilMB3017]

Well, it's pretty easy to take the starter off and test it... Just hook it up to the battery directly and see if it still acts funny.

I suppose it could be your wiring, but it's more likely the tuner didn't include a cold start map.

[beatd]

i doubt my tuner forgot to put a cold map on because i consitantly hounded him about it because it was one of my primary troubles i told him about.

[BLKTOPS14SR]

Quick question, what 370's are you using? My friend is looking at a similiar setup and we have 370's from my brother's CA lying around. Would they work? Thanks

[beatd]

i'm using sr 370cc sidefeed.

[DevilMB3017]

i doubt my tuner forgot to put a cold map on because i consitantly hounded him about it because it was one of my primary troubles i told him about.

When you say it has cold start troubles, do you mean it cranks but won't start? Like you hear the starter but it won't actually start? Or does the starter crank slower?

[beatd]

When you say it has cold start troubles, do you mean it cranks but won't start? Like you hear the starter but it won't actually start? Or does the starter crank slower?

The car will crank just won't actually start unless i keep cranking and pumping the gas pedal and after several tries it would finally fire up and run. If i turn it off right after and try to turn it back on it would be fine its just when i try to start it when the car is left alone for more than 4 hours. I'm going to go over my grounds and see if they are all good and the grounds for my coolant temp, and tps.

[DevilMB3017]

The car will crank just won't actually start unless i keep cranking and pumping the gas pedal and after several tries it would finally fire up and run. If i turn it off right after and try to turn it back on it would be fine its just when i try to start it when the car is left alone for more than 4 hours. I'm going to go over my grounds and see if they are all good and the grounds for my coolant temp, and tps.

Then it's probably not your starter - although your starter probably doesn't like you right now, lol.

CTS and TPS shouldn't really have anything to do with the cold start issue.

Check out this article maybe?http://www.nicoclub.com/articles.php?id=160218

[beatd]

Then it's probably not your starter - although your starter probably doesn't like you right now, lol.

CTS and TPS shouldn't really have anything to do with the cold start issue.

Check out this article maybe?http://www.nicoclub.com/articles.php?id=160218

lol my starter is about to get pissed on. i've checked that article and i'm down to the ecu power source and grounds. so i'm adding alot of grounds to the motor

[DevilMB3017]

I'd also add another ground cable to your battery. I have two grounded to the body in the trunk now and that helped some of my quirky electronic stuff.

[beatd]

all i have is 4gauge audio wires do you think thats good enough for grounding and power wire?

[BLKTOPS14SR]

We've used 0ga in our cars. Thanks for the info man! I'll let my friend know.

[RPS13 DRIFTER]

how is the high end with that T28?does it pull till redline?

[DevilMB3017]

all i have is 4gauge audio wires do you think thats good enough for grounding and power wire?

Bigger wire probably wouldn't hurt if you wanted to waste some money... lol

[DevilMB3017]

how is the high end with that T28?does it pull till redline?

No KA really runs until redline... lolMy engine redlines at around 7.2K, but I the power tapers off around 6.6K or so as fas I can tell from my horrible dyno sheets, lol.

A T2 flanged turbo runs out of steam a little earlier then most redlines on a KA too, AFAIK.

[beatd]

ok over the weekend i got a chance to put in the grounds: 1 from the battery tray to the intake manifold, back of the intake manifold to the firewall, and on the head on exhaust manifold side to the firewall. i'm still having cold start problems.

Should i replace the stock coil with a mds blaster coil? or add another ground to the batter from the trunk? or check the grounds on the harness to the coolant temp sensor?

[DevilMB3017]

ok over the weekend i got a chance to put in the grounds: 1 from the battery tray to the intake manifold, back of the intake manifold to the firewall, and on the head on exhaust manifold side to the firewall. i'm still having cold start problems.

Should i replace the stock coil with a mds blaster coil? or add another ground to the batter from the trunk? or check the grounds on the harness to the coolant temp sensor?

Unless your throwing any codes, I doubt there is anything on the coil wrong. A new stock coil is more then acceptable and easier and cheaper then the MSD units.

I would try yet another ground direct from the battery to your chassis.

[beatd]

Unless your throwing any codes, I doubt there is anything on the coil wrong. A new stock coil is more then acceptable and easier and cheaper then the MSD units.

I would try yet another ground direct from the battery to your chassis.

yea i'm going to double the ground for the battery to chassis, and hardwire the stock coil from the writeup and see if that would help since i have colder plugs in.

[D-UNIT]

Your 370s' are flooding the engine on the initial injector pulse sequence. That happens on my 740s' when I stop cranking before the engine starts. I have to hold it at full throttle and crank it to start it. A blaster SS coil would help burn the extra initial fuel.

[beatd]

Your 370s' are flooding the engine on the initial injector pulse sequence. That happens on my 740s' when I stop cranking before the engine starts. I have to hold it at full throttle and crank it to start it. A blaster SS coil would help burn the extra initial fuel.

After i hardwire the coil how big of a sparkplug gap could i run for a bigger spark?