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[DmC]

Yeah at this point I don't know if this is a hybrid tech,engine managment or forced induction problem. But I assume it's probably all of the three.

 Ive been trying to tune this car for about a month now and just spent from 5pm to about 3am on it and have gotten nowhere.

It's a 98 gsr stock internals engine ,converted to obd1 with a turbo setup consisting of.
a pfab log manifold a small sperco intercooler and some massive 5yo but never used ebay knock off of a t70 looking thing. The guy it was bought from was clueless said it was a 60 trim like that was a complete answer.
 
lets see what else dsm 450cc's a resistor box and walbro 255 pump. A nice looking turbosmart wategate.

the problem is that the car runs fine out off boost and just into boost up until about 7psi then it starts breaking up really bad and the wideband goes leanlike from missfires . So i'm still leaning towards an ignition problem.
 with software ive tried adding fuel and taking fuel away massive amounts either way.
the same with timing as low as 14degrees and as high as 27degrees.
it makes no differance.
changing maps ive built new roms from the ground up a few times. And just tonignt I tried a rom from the last gsr I tuned with forgings and 15psi of boost it would about hold you back in your seat.   but in this car it has the same problems 

known good parts ive swapped in
The ecu ,ignitor ,coil fuel pressure regulator ,differant 450's a differant fuel pump. We punched a hole through the inside of the fuel filter to make sure it wasn't clogged.
We checked the timing belt. It's good

plugs have been ngk 8's and 7's weve went from .030 down to .025 it makes no differance.
I'm at a complete loss with this car. I'm pretty much out of idea's
Here's a pic of the plugs

[widebody93]

Is this the same car you called me about two weeks ago? HOLY SHIT BATMAN your dedicated

[DmC]

Yeah man I don't ever quit on a car until it's perfect . Ive never had one take this long before though. 

[widebody93]

Yeah I"m going on 4 years now with my second build, only it's taken me longer to get to 500whp this time around, miss my teen years

[Corey]

if you get the chance do a pull at less then 100% throttle, like 75% and see if it still breaks up. i had a car that did the same shit and it wouldnt do it unless it was ful throttle. never figured out the problem and there was a thread on HT a while ago with someone who was having the same problem.

[CivicOCD]

could the resistor box for injectors fucked up?

if you get the chance do a pull at less then 100% throttle, like 75% and see if it still breaks up. i had a car that did the same shit and it wouldnt do it unless it was ful throttle. never figured out the problem and there was a thread on HT a while ago with someone who was having the same problem.

tps or map sensor output?

[DmC]

You can roll into it and it'll still break up and you can tell it's not right.

I haven't tested the resistor box at all. I installed it myself. But that doesn't mean anything. I thought they either worked our they didn't.

[DmC]

I actually have switched the map but I haven't fooled with the tps. you know Ive had cars do this before with a bad tps. I'll go check the datalogs.
I wish cromepro was as good as freelog.

[RobC]

could it be the butterflys in the intake. my buddys boosted blue top was doing the same thing when tvis was opening. maybe ur having the same problem. try to manully keep them open with vacuum

[DmC]

Good Idea man.  But iI forgot to say it has a skank2 manifold. so the butterflies are gone.

I went through the logs tps seems ok but not perfect only read's up to 98%

[DmC]

anyone have any other idea's?

[Towdogg]

anyone have any other idea's?

Throw that Skank2 in the trash! 

[BoostForLife]

The the wiring for the resistor box. Make sure it's all perfect, I had one out of the 8 wires switched with another one. So instead of all 4 going to the resistor box, I only had 3 and last one straigth to ecu, it was just fucked up. Was fine up to 5500 at 8psi on b16 and then lean out/break up. Worked fine after I rewired it.

[Adam Hopkins]

New wires, Cap, button. Is the dizzy cap wet inside at all?

[chris]

you ever check fuel pressure.

[HiProfile]

changing maps ive built new roms from the ground up a few times. And just tonignt I tried a rom from the last gsr I tuned with forgings and 15psi of boost it would about hold you back in your seat.   but in this car it has the same problems 

If it is misfiring, the fuel isn't turning to carbon, which doesn't deposit & washes the rest off. First I'd lower the boost until it doesn't do it. Next I'd try it down past .020" to be sure (maybe even .015", be crazy) to see how it does. The other thing could be the wiring harness. Cold solder joints & corroded wires can ruin your day, so try another engine and/or ecu harness if you can. Also check your battery & all engine grounds - tranny, valve cover, AND t-stat housing (for the harness).

As boostforlife said, it might be the resistor box - wires or solder joints. The obd0 cars actually do run that ground wire back to the ecu.

[sewell94]

  i never seen anything about trying a new set of wires, so that'd be the first thing i swapped out.

  what i would do, is take a dizzy with plug wires still attached from a good running car, and swap it onto this car.

[sewell94]

As boostforlife said, it might be the resistor box - wires or solder joints. The obd0 cars actually do run that ground wire back to the ecu.

  the resistor box doesn't have ground wires,   they're all power wires, the wires comming from the ecu directly to the injector are grounds that are used to pulse the injector.

[widebody93]

Guys you all have good replys"no doubt"
But knowing Dennis"DmC" these are the common check points "ex. the wire harness bits" and I'm sure he has covered them already, except for the tight plug gap,


But DmC have you tried a newer TPS, hope the one you got isnt a rivit syle unit.  Also ask the owner if the gas is new or is it been sitting in the tank all winter.

[DmC]

you ever check fuel pressure.

He did they have a fuel pressure gauge on the fuel filter and he had a guy lean out the window while it was doing he said between 43 and 60 psi. I need to get a real gauge on it

  i never seen anything about trying a new set of wires, so that'd be the first thing i swapped out.

  what i would do, is take a dizzy with plug wires still attached from a good running car, and swap it onto this car.

 It has a new cap and rotor button the plug wires are new msd's

Ive wanted to swap in a whole other distributor but we don't have one laying around to try.

[DmC]

Guys you all have good replys"no doubt"
But knowing Dennis"DmC" these are the common check points "ex. the wire harness bits" and I'm sure he has covered them already, except for the tight plug gap,


But DmC have you tried a newer TPS, hope the one you got isnt a rivit syle unit.  Also ask the owner if the gas is new or is it been sitting in the tank all winter.

I haven't tried the tps but I think it is the riveted one. I don't feel that tps is the issue. It's usaully obvious in the logs when one is bad.

And hey just because I fool with cars all the time doesn't meen I can't overlook something simple.

[sewell94]

New doesn't always mean good.  I've seen more than 1 set set of brand new wires end up being crap.

I've seen plugs have to be gapped as low as .014, but at 7lbs i've never had to gap that low.

 The gas being bad is a very good possibility.

  I'd almost think map sensor after trying a set of good wires, i've seen a few stock ones quit reading in the 8lbs range, so its possible that at 7lbs it could happen

[DmC]

New doesn't always mean good.  I've seen more than 1 set set of brand new wires end up being crap.

I've seen plugs have to be gapped as low as .014, but at 7lbs i've never had to gap that low.

 The gas being bad is a very good possibility.

  I'd almost think map sensor after trying a set of good wires, i've seen a few stock ones quit reading in the 8lbs range, so its possible that at 7lbs it could happen

  Ive swapped in my map sensor and I forgot to say in my reply to Jeremy that the gas is new...And on the plug wires there MSD's so it's a real good chance their bad.

[sewell94]

Msd wires for our cars suck ass, i'd rather have a set of cheap ass zato zones.   

  I keep 4 or 5 good sets of wires in my tuning drawer, that i use when people come in with msd wires.

[DmC]

I'll make him get some plug wires then. They just seem like a good possible part of the problem to me mainly because the car owner is so proud of them.

[Random Hero]

did you ever have the line off the fuel rail (from filter)   ??

make sure you have the correct washers on it and if need be you can drill a hole through where the banjo goes on for better flow.

It really sounds like a fuel delivery problem

Things I've had cause this problem

Wrong crush washers on the banjo (the ones without the recesses to flow through the dampener)

Bad/Old fuel filter

Bad/Old Plug wires

3 Bad walbro pumps

Bad injector box wiring (lol oops)  the car runs fine until the injectors really need to start working

Bad FPR

Oh and I know alot of people give me shit for this but I run my plugs at .018 and have never ever had a blowout problem since.

[DmC]

did you ever have the line off the fuel rail (from filter)   ??

make sure you have the correct washers on it and if need be you can drill a hole through where the banjo goes on for better flow.

It really sounds like a fuel delivery problem

Things I've had cause this problem

Wrong crush washers on the banjo (the ones without the recesses to flow through the dampener)

Bad/Old fuel filter

Bad/Old Plug wires

3 Bad walbro pumps

Bad injector box wiring (lol oops)  the car runs fine until the injectors really need to start working

Bad FPR

Oh and I know alot of people give me shit for this but I run my plugs at .018 and have never ever had a blowout problem since.

  Lets see here.. umm I feel it's fuel delivery too. Ive had the ignitor and coil from my car on his. I did check the fuel like and the washers were put on wrong I fixed that but still the same problem I will try drilling it out though.
The fuel filter looked wierd inside so he just knocked a hole all the way through the center of it but it's still the same shit.

I just got off the phone with him and he's buying new non msd plug wires. fuel pump may be bad but I did swap his stock pump back in and it acts the same way but it's a stock pump so who knows. It hasn't made any power yet so it's not really using any gas to make power with.

I'll take the resistor box off and replace it with another one and check all soldering it only has one solder joint though I depinned the wires and plugged it into the harness it's pretty slick I had to solder a pin into the power wire to plugg into the dead plug.

all good idea's you all thanks I'll just keep checking and trying this stuff until it works.

[widebody93]

All this knocking a hole in this, drilling out that

SOUNDS LIKE DOOMS DAY
for an injector to get clogged

[sewell94]

A stock pump on 7 lbs will be fine. Normally a clogged inejctor will have issues all the way through the rev range, 


is the idle always smooth or does it roughen up sometimes??

[chris]

throw the stock pump in