LIke the title says, I'm currently running a 95 GSR motor in a 98 Dx. Backwards converted to OBD1.

Unfortunately I don't know exactly when it all started messing up but here's the jist of it.

A while back my car overheated one day. Fan never kicked on. Still haven't fixed that, but thats another issue. Anyways, it seems like since then, there's been a minor sputter at lower rpm, 2500 and below, anything above that and it was fine. Then, within the last 2 weeks or so, its just gotten worse. going as high as 4k where it was sputtering/backfiring. White smoke coming from the exhaust once vtec engaged. Then, finally, it just crapped out. I thought it was a head gasket. Car almost died. had to rev it up to like 6-7k and feather the clutch to make it roll home. If I let it fully engage it would die. So i get it home, swapped the head gasket, and fire it up. No difference. It runs fine when the car is cold, but the second it gets warm, or regular operating temp, it starts ****ing up. A friend suggested MAP and TPS, so I swapped those. No difference. I thought maybe it was my distributor. Got a new one from autozone. No difference.

I dont know what other sensors could cause this to happen, so I'm thinking i might have warped my head one of the times it overheated.

Strangely though, even when its running like absolute **** and about to die, or does die, I never get a CEL...


anyone have any ideas? I need this car fixed asap cuz its my DD. Thanks for reading.

 

Does the CEL work?

A cold engine runs in open loop, where the ECU ignores the O2 sensor inputs. Once the engine has warmed up, the engine runs in closed loop, where the ECU uses O2 sensor inputs to determine the proper air-fuel ratio. Check whether unplugging the O2 sensor prevents the problem. If so, replace it.

 

Yes, CEL works.

I'm currently running one o2. Just unplug it and fire it up?

 

Yes

 

Ok. Its 12:30 am here so i'm not gonna do it right now. (my car is kinda loud) ill do it when I wake up and I'll let you know what happens.

 

Yes, this. It sounds like a closed loop problem to me if it runs fine cold.

No CEL though, huh? I had some bad bogging/powerloss problems with no CEL on my CRV that sounded somewhat similar to what you're having. After 2 weeks of screwing around with it, I found it to be a clogged cat. You might take a look at that.

 

Tried the o2 sensor thing just now, Unplugged it, started her up. Got a CEL. Drove it around, for a minute i thought it was the solution, but I figured, let me drive this just a little longer to make sure. Thank god i did. Like a minute later it started right back up.

As for the guy who suggested cat, i'm not running one. Any other ideas? I'm at wits end with this.

 

Compression test the cylinders when the engine is fully warmed up.

 

should i do it both cold and hot? or just hot?

 

Generally, cylinder compression tests are done when the engine is hot. It would not hurt to run the test on a cold engine, but as the problem occurs only when the engine is hot, this is also the most relevant condition to make the measurements.

 

Ok. Just did a compression test. Got 200 clear across the board. So I put it back together, but when I did, I used different plugs (a spare set i had layin around) just for ***** and giggles. Fired it up, and it drove perfect. even hot. actually i dont think it ever drove that good since i've owned it. Turned it off, about a minute later, turned it on, ran like ****.

its gotta be something electrical then right? why would it be fine one second, and shitty the next? should i try a different engine harness?

 

You might want to test the coil and igniter unit inside the distributor. How do the cap and rotor look? Any sparks jumping from the plug wires?

Testing the FPR and fuel injectors might also be a good idea.

 

I had swapped it out with a different distributor just the other day, thinking it was the distributor, but it made no difference. how do I test the fpr?

 

The tests below will only yield useful information while the problem is happening.

Any sparks jumping from the plug wires? Check at night in a dark place.

For the FPR, you need to connect a fuel pressure gauge and check the pressures with and without the FPR vacuum hose attached.

Also check whether the fuel injectors are clicking and whether disconnecting a fuel injector plug does not make the problem worse.

 

I forgot to mention, my engine harness has been "tucked" so its been modified before, etc. which is where i think the problem lies. also, i don't have a fuel pressure gauge...

 

Ok... Finally got around to being able to work on the car. Had some lousy weather lately, and been feeling like ****. Anyways, instead of guessing with more "testing" of sensors and stuff, I decided to run the car in obd2 so I can use my obd2 scanner and see what she says. So I swapped out my ecu. Plugged in the scanner, it gave me 2 codes.

P1337 - CKP (CKF) Sensor no signal
P0140 - H02S B1 S2 Heater Circuit Malfunction

I knew I was going to get the CKF/CKP one, but the Second one would explain why my car has been overheating. The fan works, the relay works, the fuse works. I havent checked the actual switch though. Could that be the cause of that?

Anyways, I decided to drive the car, with ^^^ those codes running, just to see. I drove it around for a good 20-30 minutes, turned it on and off a few times, because like I said before it would be fine one minute, then restart it and it ran like crap. I restarted it a few times with the obd2 ecu in, and it ran fine. Had the 2 CEL's on, but ran fine. No sputter whatsoever.

However, I did notice something a little goofy, but maybe once I clear the CEL's it'll fix itself. As I was driving my tach was going ape ****. Just bouncing all over the place. Idle would be fine but it'd register at zero rpm, cruising at like 45 in 5th, should be around 2500ish, it was bouncing from 2k-4k. like.. just jumping around. never steady. Quite honestly that is the least of my concerns, but I figured I'd let you know its happening, in case that could be causing problems somewhere else.

Thanks for reading all that. Let me know what you think.

 

P0140 is a secondary O2 sensor code and would have nothing to do with overheating. The codes are not likely to cause your problems when the OBDI ECU is installed.

The jumping tach while cruising suggests an ignition system problem (plugs, wires, cap, rotor, coil, ICM).

 

I agree with this. However, like i stated in an earlier post, i tried a different distributor, with a new cap and rotor, plugs are newer (5 months old, and wires look fine)

however, i took a look around at some of the wires that had been lengthened for the tuck. Injector wires look solid. but when i came over to the distributor, i found something that stuck me as odd.

let me see if i can find a way to post a pic on here since HT doesnt like my photobucket account... brb

 

ok, its kind of hard to see in the pic, but in my hand is a yellow wire to yellow wire, with a brown wire soldered in there too, but then it was cut.. it was all taped up together, but i dont know how it would have gotten cut?

does anyone have a wiring diagram? for this? im trying to find one but idk exactly what they modified so im not sure what to reference to....

 

heres another one

 

since the pics are blurry, i took down the wiring info/colors.

EWH side Dizz plug side


THICK black/yellow-----------------thick black/yellow

red--------------------------------red

dark blue --------------------------dark blue

lime green -------------------------lime green

white/green ----------------------- white/green

light blue ---------------------------light blue

white --------------------------------white

Black &
Brown/black ------------------------- black

yellow &
brown (cut one in pic) ----------------- yellow...


sounds good to me, except that cut wire. not sure whats going on with that.

 

bump

 

I think I have a lead... For some strange reason, today, i decided i'd test my battery. With the car running, i pop on a multi meter, i get 12.5 volts. take it off 12.5~12.6...

 

Anyone?

 

you need to fix that wiring, go on http://www.ff-squad.com/technet/ and find there dizzy schematic, thats what my single cam was doing id be driving it it would run fine id hit a bump and it would die or run like **** because my distributor wiring was a complete mess. your best bet would be to just get a new harness un cut.