Major Problems...

[AWD monster]

I have a customer that brought me their car for some work, and for me to diagnose a few problems. I did a boost leak test, and fixed all boost leaks. Next i tested for vacuum leaks and fixed all of those. His electronic boost controller was installed wrong, so i reran all brand new vacuum lines, and redid the install of the boost controller.

When your cruising and you try to get on it, it pops and crackles but doesnt move. It doesn't get a chance to build boost before the popping and crackling. From outside the car it sounds like an anti lag when you try to get on the gas. The car has a walbro 190 hp, and 550cc injectors with a 16g. I changed the spark plugs to see if maybe they were fouled out, no go. Any ideas?

My thoughts:

Mass air flow
Spark plug wires

 

[kenamond]

I have a customer that brought me their car for some work, and for me to diagnose a few problems. I did a boost leak test, and fixed all boost leaks. Next i tested for vacuum leaks and fixed all of those. His electronic boost controller was installed wrong, so i reran all brand new vacuum lines, and redid the install of the boost controller.

When your cruising and you try to get on it, it pops and crackles but doesnt move. It doesn't get a chance to build boost before the popping and crackling. From outside the car it sounds like an anti lag when you try to get on the gas. The car has a walbro 190 hp, and 550cc injectors with a 16g. I changed the spark plugs to see if maybe they were fouled out, no go. Any ideas?

My thoughts:

Mass air flow
Spark plug wires

Is your profile for your own car or is it for the car you're working on? If it's not the car you're working on, what mods does the car have? If your profile *is* the car you're working on, could the owner have a bad tune? Did the owner change something and then start seeing the problems? If so, what?

 

[Ultimatedsm]

Make sure the plugs are gapped at .028 and is he running some kind of air/fuel controller for thos 550's? If he isn't, he could be running overly rich. A mod list won't hurt as well.

Ultimatedsm,

 

[AWD monster]

Is your profile for your own car or is it for the car you're working on? If it's not the car you're working on, what mods does the car have? If your profile *is* the car you're working on, could the owner have a bad tune? Did the owner change something and then start seeing the problems? If so, what?

oops. I apologize. I've tried posting this post now for the last 4 days, i forgot to include some vital information. haha.

The customers car is a 97 GST, big 16g with 550cc injectors, and a 190 pump. He has an afc as well. The only thing that changed on the car is the work i did, vacuum lines, fixed boost leaks, and vacuum leaks.

 

[2bclutch]

I have the exact same setup with the only difference being mine is a 98 GST. I would definately make sure that his AFC Settings are set correctly, the spark plugs are gapped correctly, and you could try the spark plug wires as well. I personally think the popping and crackling sounds has something to do with air/fuel mixture. If his boost controller was that badly installed god only knows how the thing is tuned with that AFC.

 

[AWD monster]

Well i did mess with the AFC some. Im going to replace the plug wires, and take a look at the coil pack, and try a working MAF, the more i think about it, i think its an ignition problem. Ill post back after i put a new coil pack, wires and what not else on.

 

[kenamond]

Well i did mess with the AFC some. Im going to replace the plug wires, and take a look at the coil pack, and try a working MAF, the more i think about it, i think its an ignition problem. Ill post back after i put a new coil pack, wires and what not else on.

Do you have a logger or some way of tuning?

Did the owner change something and then the car started misbehaving?

I agree that you should check the plugs. What kind are they, and how are they gapped? Everyone around here recommends NGK BPR6ES plugs gapped to between 0.028" and 0.031".

 

[fourreGsixty3]

Check the plugs for fouling or hot spots. Change the plugs out to the coldest possible plugs without fouling, so NGK6s should be good for his mods. These are the first things I would change, why buy a 300$ coil pack, when the problem could be from same platnium plugs that you could replace with some copper plugs for 2$ each. Like others have said check the AFR, it is probably running rich, because it seems like it was hacked together, so no telling what the settings for the AFC are at. Also check each plug to make sure ther are gapped at .028, people have done it between .026-.032, but .028 is the happy medium that everyone does and has no problems.

Dustin

 

[AWD monster]

Ok, the plugs i replaced and are not fouled out. They are bpr6's. They are gapped properly, and he has an AFC which i have tweaked. I've gone through and redone all the work the previous shop did. The car is running on my modifications now. As for the coil pack, i have a many perfectly good coil packs laying around, as i have sent many shells to the wrecking yard. My garage is a DSM graveyard itself. I'm going to do some work on this car today, I will post my findings once i get some work done.

 

[spyderturbo007]

When you say that you "tweaked" the SAFC, what do you mean? If you could give us all the SAFC parameters, that would be the best thing.

Such as, TPS trigger points, Ne Points and corresponding correction factors, for both the high and low throttle maps. Also, what type of sensor is it set on? Which was does the arrow point?