HEEEELP I have a surge at WOT

[Hafrod]

I have a surge at wide open throttle. I have an 87 GN. Stock turbo and intercooler. Usual mods- 17 lb 93 octane chip from poston ( I also tried an older Kenne belle 93 oct. 17 lb chip too), adjustable wastegate and regulator-set at 42 with line off, Reds fuel pump, Kirbans 30 lb injectors,No cat with Hooker exhaust, K&N cone, I have put on BRAND NEW coil pack( 2nd one) , module, 02 sensor, fuel filter, AC R43ts plugs, boost sol., wires, IAC sol. , billet vac. block, I have cleaned the throttle body and intercooler. I had this surge before I did most of this work. My fuel pressure goes to 55 lbs at wot and my boost guage needle goes to 16 lbs. I noticed this morning on my way to work when I punched it the boost guage went to 18 or 19 for a second then stayed at 16. It is not a constant surge but it is bucking BUT ONLY WHEN I'M ON IT. On my friends OTC last week we had 900 something on the 02 and we got at one point 6 degrees of knock. I just changed the wastegate out last night . it had a stock one on it and the boost was 13 lbs. It's holding 18 lbs of vac. . I checked the TPS last night and it's .42 and 4.6 wot. I have only had this GN for a month and I bought it NOT running. I changed the crank sensor coil pack and module before I found out the CCCI fuse was blown. Then it started up. I have rapped on the MAF and the idle did not change. This surge has got me going nuts. Can someone give me some examples of some things that will cause a surge at WOT. I checked the wastegate lines and they look fine

 

[don86T]

Check the battery cable between the battery and the starter. The insulation may be damaged causing a short to the frame or header. Also did you find what caused the fuse to blow? That may be causing the problem as well.

Don

 

[onefastjackass]

I don't know about the postons chip but it may have too much timing.

You actually are probibly having much more knock then showing.

When my otc shows knock retard then my direct scan shows about six times that and the car lays down.

I don't know if it can't get the true KR because its refresh rate is too slow or what.
I use mine for basic stuff tps o2 setting etc but i don't dare rely upon it for showing correct knock numbers

Also 900 is way too rich 760 to 820 is what most people run.That could also cause it to surge.But every car is different.

I would drop the boost a pound or two and also tune the car to about 800 and see if it still does it.

Once again I don't know the postons chip timing at wot if you have that info it may help.

I have heard that the kenny bell chip has high timing and have yet to hear of anyone being able to run more then 15 psi with it without knock retard.

Hope this helps

 

[blackstallion]

I used to run wa kb chip #9006 when i didn't have alky i would get about 5-7 krs 91 octane I would check the coil pack first.I had the same problem at wot,and my coil pack was knew it was just a srewed up new one then i put my old delco coil pack in problem was solved,you say your car is seeing about 900 mv at wot,for how long does it lean out? When u first stab it the mv go up then lean out and stay somewhat even 660-820 mv,try lower your boost down to 10-15 and see if it still surges or bucks,if it does not yor problem is and ignition problem with more boost it puts a harder strain on your ignition more boost more compression harder to fire check your plug gaps.35 should do it i run mine at 0.32 20+ pounds.Oh yeah the kb chip does not have alot of timing its a chip that like boost but its pretty weak its more of a safe chip,u should use at leats 93 octane if u can get it or 91 with 3 gallons of xylene to take that kr way wich kills power 5kr is ok but thats it 7 is too much and your losing power with 5kr try to get 0-2.good luck