Engine bogging under load

[frozenrice]

I finally got the turbo installed in the car. Everything seems to be okay in terms of idling and revving the engine. No check engine lights, the AF gauge seems to be reading where it should once it warmed up, no smoke coming out of the exhaust, no major fluid leaks that I can see. It would seem everything was okay.

Today I finally rolled the car out of the garage and onto the street to take it for it's first ride under boost. As soon as I try to start moving the car, the engine bogs down and pretty much dies. If I'm quick enough with the clutch and gas and take the load off the engine, I can usually save it from dying altogether. If I rev the engine with with the clutch disengaged it will rev all the way to red line, but as soon as I put it in gear and try to move, it'll bog down as soon as I try to give it some gas.

I'm stumped as to where to look. I'm thinking it might be something to do with how I have the vacuum lines, wastegate and blow off valve all plumbed.

Anyone with any suggestions?

BTW, it's a b18a/b LS setup. T3 with external wastegate with manual boost control if it makes any difference.

[RickDaTuner]

sounds like a fueling issue.. but then again your say AFRs are good.

May also want to look at your spark plug wires, they can cause this, and only presents itself under load.

can you wot to redline in neutral? or do you have to feather the gas to get it there.

[frozenrice]

I can WOT to redline without any problems and the fuel pressure gauge reads 38psi. I did have a small fuel leak at the adjustable FPR yesterday, but I fixed it. Turns out the nipple on the FPR from a Civic is smaller than an Integra so the return line and clamp was too big. Swapped in the Integra bottom half and it sealed up no problems and adjusted it to get the 38psi.

I'll have to check out the plug wires. Didn't occur to me at the moment. I tend to walk away from things for a bit when I get frustrated. Better than kicking something in or stupid like that LOL. Thanks for the suggestion.

[frozenrice]

Could turbo issues have the same symptoms? One thing I noticed after I initially fired up the car was the boost gauge readings. During idle the gauge would read negative but not go past zero when I revved the engine up. Is that normal? I thought the boost would at least read up to what ever the wastegate is set at.

[Twin_Cam_Turbo]

Its hard to build boost with no load.

[Joe-G]

You don't build boost while revving in neutral. At least without some type of boost builder from what i know.

[RickDaTuner]

Map sensor would by my next guess.

[frozenrice]

Okay so then I'm good so far if no load means no boost. For the map sensor, shouldn't the CEL come on if there was an issue?

[gpomp]

what ems are you running?

[Mr_ET]

Tell me its not a stock ecu please

After you answer the ems question I have 2 more what wideband and what is the fuel setup and adjustments in the ems to accommodate?

[frozenrice]

Not really a stock ECU. It's got a ZIF socket in it and I am running OBD0 (for now) w/ a chip burned with Turboedit. Fuel setup is for 450cc injectors with a 2.5 bar MAP sensor.

As far as wideband, if I understand it correctly, I'm not using one because I'm running OBD0. As far as I know, Turboedit doesn't support datalogging (the last time I looked) since it's the only program out there that solely supports OBD0.

[sr20s14zenki]

So do you have the 2.5 bar map sensor ?

[frozenrice]

Yes it is installed as well as the injectors.

[frozenrice]

It's not the plug wires. Got a new set and installed them. A slight improvement but not by much. Cap and rotor?

[RickDaTuner]

post pics of the cap and rotor from the inside.

If you had any improvement from changing the wires then it was time to change them anyway, a miss fire from plugs wires under boost can be trouble

[frozenrice]

Looks good to me....


» Click image for larger version


» Click image for larger version

[RickDaTuner]

Its a good thing you replaced those plug wires, notice the bottom left probe on the cap...

All that splattered material that you see all around that probe is from too much spark plugwire resistance. All the other ones have normal wear. through.

Your coil seems to be on its way our as well. if you look on the rotor lead the spark arc dies 1/3 of the the way through the spark cycle. it should look like this \_____/ all the way across the bottom.

all though there are these issues, I still feel that its a tuning issue. either the map is reading wrong, or the injector duty cycle is too short.

[93VR6]

In your first post you say you are getting good AF readings then later on you say you don't have a wideband since you are running OBD0, which is it?

my guess is also on tuning. I think you may be drowning out the spark with excess fuel.

[frozenrice]

What I mean by wideband is I am not running an aftermarket UEGO 02 sensor. It's just the stock one with a simple AF gauge. I didn't say the readings are accurate, just that they "seemed" fine.

[sr20s14zenki]

Definately tune. 0-1v is not enough to go off. 1 led light in that thing could be 5 afr points, lol.

i would reccomend buying a uego just for reference purposes. It makes a great diagnostic/tuning tool.