Hi everyone...I've been trying to figure out whats wrong with my car for the last few days. I have a 2000 Civic Dx hatch with a turbo'd 94 GS-R swap (running the OBD1 p72). This will be the first time on the road since the swap.
The problem is exactly what the topic says, when idling, it fluctuates up and down, sometimes it will stall itself out it goes so low. (Will 90% of the time when the motor's up to temp.). When accelerating lightly, it lacks power, and you can feel the engine missing sometimes. When you partly open the throttle, sometimes nothing happens until say 15-20%.

I spent the better part of yesterday [freak]ing with the TPS (3 actually). Turns out they're all fine, giving accurate, smooth readings.

-I replaced the MAP sensor with a known good one.

-Verified proper IAT resistance.

-Changed ECU's to a P06 Automatic , no change.

-Set timing.

-Tried to adjust the idle screw, but it has no effect, and when you pull out the IACV anyway (as the manual says to), it definitely stalls/will not idle.

Tomorrow I'm going to:

-Check/change spark plugs

-Change fuel filter

-Swap injectors

-Clean/inspect IACV

I may frig with my IAB wiring....try and get them to work, and test the ICM.


Anybody have anything else to add to my list of possible causes?

 

what tune are you running and what injectors?

 

is the firing order correct?

 

Its the stock ecu, I'm not using enough throttle to produce any boost, so it should run fine.

And it doesn't always miss, so the wires are on there right.

 

why are you runngin a boosted car on a stock ecu? doesn't matter if you "dont use enough throttle to produce boost" you should at least run a basemap for your setup. doesn't sound like that though.

i would double check timing and make sure the MAP and TPS plugs weren't mixed up when installing the new motor

 

well, since I've been toying with the TPS for hours, I'm sure they're connected properly....besides, theres no check engine light on.
and I know technically I should be running a basemap, but my tuner said it's not required. And I'm not second guessing this guy...since he's tuned hundreds of honda's in atlantic Canada, including his own 640 HP integra.

 

bump

 

i would definitley second guess any "tuner" that said its cool to run your car turboed on the stock ecu

why dont you have your tuner tell you whats wrong with the car?

 

well, he never said it was ok to run ***** out, he said it was ok to drive it lightly. The plugs look fine, its not knocking, I think I'll trust him. He knows what he's doing. Besides, I'm not running a tiny turbo here, I won't have boost until around 4000 @ WOT.
So, negating the fact that I "shouldn't be" running a stock ECU on a turbo'd car, does anyone else have anything else to check?
Timing belt position is also OK

 

what injectors still stock?

 

stock injectors, yup...OBD2 injectors/clips

 

"messing with the tps for hours" please explain, trial and error method or using a meter to determin if the closed/open set points are generating the correct signal voltages back to the ECU and that they are steady at all points and don't fluctuate (noisey pot) .... which is it ??

 

originally was using the trial and error method, until I figured out how to calibrate it. Hooking up my TPS to a meter, I easily adjusted the output signal to have a range of .45v to about 4.5v. The output voltage/resistance changes smoothly on change of position. I'm fairly confident it's not a TPS issue.

 

bump

 

maybe you have a vaccuum leak? hunting idle.. no boost.. tps is good.. maybe the timing belt isnt properly tensioned?

 

well, I checked the timing belt position, I thought the tension was alright...I wouldn't think tension would affect it by that much. I'm also not dismissing the possibility of a vacuum leak. Whats the best way to test for that? (I know all my hoses are good) If it was leaking anywhere, it would be at the intake manifold gasket.
And does anyone know if a non v-tec civic ICM is the same as a GS-R ICM?

 

the part numbers are different but doesn't mean that they might not be interchangable. the haynes manual has a section on how to test the ICM with a multimeter.

 

When I got the motor, the Coil and ICM were burnt out, so I replaced them with parts from a civic dizzy.
Today, I took the distributor off, replaced the coil and the ICM with ones off my DD/beater civic. When I put it back together, It ran like ****...way worse than before, idling at like less than 500 rpm, sounds like its running off like 2 cyl...won't rev.
So I put everything back the way it was originally, and it was still running horrible. And yet still no CEL.
Any insight?

 

and does anyone know how to depin an obd2 injector plug?

 

A vacuum leak would cause a high idle, not an idle that stalls 90% of the time. The ICMs should be functionally identical as they know nothing about timing.

You said you set the base timing? Was it with a timing light, when the engine was at normal operating temp, and with the service connector jumped? It sounds to me like your timing is still out of whack.

 

Well, when I timed it, it was up to operating temp, was timed with a timing light on #1 cyl...timed it to the red mark on the crank pulley, and I'm pretty sure the service connector was jumped.
Besides, when I started it up N/A for the first time (never drove it on the road), it didn't idle like this. Not even adjusting the timing limit through its entire range will dramatically improve the way it's idling.

 

Bump, just because this is [freak]ing retarded.

 

Anyone?

 

I'm not running a knock sensor. Its wired, but I don't have one to put in it. Oddly enough, it's not showing a CEL for that either.
Could that cause these problems?

 

anyone??