more 16v digi 1 fun - coolant temp sensor?

[laychooba]

arghhhhhhhhhhhhh.
one day it runs good, next day like balls. stabbing something
in the near future is imminent.

so i was having issues with pinging, so i got a new chip from TT
in my second/spare ecu. plugged it up, tried it out, seemed to be running
fine. now a NEW problem arises.

start the car cold, no problems. no isv, so it's a little groggy for a minute
but then starts to run fine. drive it around for 5-10 minutes, no problems
whatsoever. when the car reaches half temp, you could be crusing - give
it gas and nothing. full dead.

when i pull over, crank it over to start and it just cranks and cranks. nothing.
if i unplug the injector harness, crank again, it'll sputter/run for 3 seconds
and then die. plug back in the injectors and it'll start and run for about
30 seconds and then dead again. it's like it's flooding.

if i disconnect the CTS after is stalls, do the injector thing, it'll start up and
run fine. i can drive it, won't stall, runs very good actually. i just don't hammer
it and drive it smooth.

i had a spare CTS at home i tried swapping, didn't do anything. same thing.

i'm kinda stumped! maybe it's the chip in the ECU? it was weird, it was running
fine for a few days with the new chip and now it's all squirely.

[boost is better]

I had a problem just like this. would run great until about half temp then start running very rich.turned out to be a shorted o2 sensor the computer does not read from the o2 sensor until it goes closed loop i think at about 80 degrees. also had a problem on a digi swap 16v with the coolant sensor same deal good sometimes then run very bad it had a brand new coolant sensor but it was not a bosch one. and sure enough after pulling my hair out and driving around with my multimeter i would jump out when it would start running bad and ohm out the cts and sure enough it's resistance was nowhere close to the range chart put a new bosch sensor and ran 100%. just a few ideas.

[laychooba]

is it possible i read something somewhere that said don't
disconnect the CTS when the car is running/key on on? because
i did that a boat load of times.

[rcortez13]

I've remember reading not to disconnect the ISV while the car is running. If I remember correctly when your timing the car you disconnect the CTS while it's running to adjust.

Have you tried running the old chip to help pinpoint the problem?

So did the new chip fix the pinging issue?

I had the same issue that "boost is better" had but my fix was totally different. I replaced the connected at the end of the O2 wire and I didn't remove enough of the shield, the shield was making contact with the signal wire. After the car warmed up and went into closed loop it ran like poo.

[laychooba]

i just disconnected the O2 sensor, left the CTS plugged in and went for a
rip. still doing the same thing. it's not that it's even running rich, it's like it
INSTANTLY floods. then it won't start again.

i would have to disconnect the fuel injector wire, crank it to burn the gas in
the cylinders to get a little sputter, then reconnect the injectors and floor it
and then it'll run and idle.

basically the only way i can drive it is with the CTS disconnected. when i get
home i'm going to swap computers to see if that's the problem. weird though,
was running fine for a few days after i put in the new ECU with chip.

(also side note, when i ordered the chip from colin @ TT, i didn't mention to him
that i have bigger injectors (32 lbs/h)

[laychooba]

tried my old ECU, same thing. no change.
02 sensor, plugged or not plugged, no difference.

CTS plugged when cold, works fine until half temp
CTS plugged when hot, stalls and floods
CTS unplugged when hot, runs/idles/drives
tried two different new CTS sensors, no difference either.

[rcortez13]

That's good. And I mean that in a good way. If your getting exactly the same symptoms it's possible when you removed the ecu you might have a broken wire or pulled a pin out of the socket.

[laychooba]

That's good. And I mean that in a good way. If your getting exactly the same symptoms it's possible when you removed the ecu you might have a broken wire or pulled a pin out of the socket.

that's a smart man right there.
here? NOT SO MUCH.

ECU wiring harness, passing through the fender



removed tape



wrapping it up now, putting clamps to hold the harness away from
the tire.