Car can't drive when cold. only once warmed up. Misfiring when Warm....

[Ryann]

A cold engine needs a richer mixture. Even a small intake leak will lean out the mixture enough to cause problems.

I would eliminate the possibility of vacuum leaks first, particularly since someone else has been under your intake before.

I would tend to doubt AFM problems simply because you aren't getting a CEL, although I've seen certain modes of failure for MAF's and AFM's fly under the radar on earlier systems.

[fiftytakedowns]

I made some headway today.

the sensors Checked out pretty good CPS had a like 650 ohm reading while the camshaft sensor was like 1300 ohm.

I think it's a spark issue becuase now it's acting like it's hitting a REv limiter. Im hoping there isnt some fucked Wiring somewhere. and I added and extra ground between the shock tower and the intake plenum.

Any Ideas?

I am getting two different ECU readings

Of my MARK D chip ECU the engine wont rev past 2K rpms and its spitting out a 1271 code

off the stock ECU no chip Im getting a 1244 code and it's revving up to 3.5K rpm before it does the misfire/sputtering now..


EDIT:

I thought I would mention that When the car was warmed up this misfiring, sputtering jerking Etc. WAs intermittent and would show up randomly. I also tried wrapping the coil wires separately too see if there was a noise issue etc... but to no avail.

[immajackuup]

sucks to be in your shoes.

[Ryann]

Do you have another spare DME to swap in? If you don't I would seriously be happy to mail you mine.

As I think you said earlier Google finds threads with these same codes and symtoms. Weird.

[fiftytakedowns]

Do you have another spare DME to swap in? If you don't I would seriously be happy to mail you mine.

As I think you said earlier Google finds threads with these same codes and symtoms. Weird.

NEW UPDATE:

So I do have a SPARE DME.

and its been even more frustrating now, as I am leaning towards fuel problem now.

I'll be driving, the car will be going fine, and after 30 seconds of driving, it will do agressive sputtering, and nearly impossible to drive. my narrowband gauge is going all over the place, but moving to the lean area. I think... But If I take out the ECU and put it back in, it resets and goes back to normal. until 30 seconds are over.

Gets worse with the chipped ECU.

[fiftytakedowns]

Did some sensor Testing:

Coil 1: WAs Sparatically Changing Ohm Levels:
from .03 to .05
Coil 2: .015
Coil 3: .015
Coil 4: .015

These were the coils Off of a Coil on Plug conversion, not sure if that makes a difference.

AFM:
got a consistent reading between pins 3 & 4 to 3.94V through -.06V
Between pins 1 & 2 : 3.8 V

TPS:
At idle between Pins 1 & 2 4.3V
Full throttle: .96V

Between pins 1 & 3 5v
Between pins 2&3 at Idle .62 V
full throttle: 4.0V

[fiftytakedowns]

Good news: its not the coils.
got some new ones, and they didnt change anything.
I put some plug wires in, and then had the coils on separate, and then I disconnected the plugs wires, and there was still spark jumpin between the coil pack and the plug wires.

what Is really odd is how if I disconnect the DME and plug it back in again, the problem goes away temporarily.

[fiftytakedowns]

mechanic says its a misfire, where should I check next?

BTW i unplugged the camshaft sensor and it changed nothin, same synptoms.

[fiftytakedowns]

I was getting a consistent 45 PSI at one of the fuel lines and 55 if I disconnect the FPR . I only tested one, but I figured the return line wouldnt have 45 PSI anyway.

I replaced the ground strap that goes from the Frame to the like engine mount arm thing. I have another ground strap that I attached from the shock tower to the intake throttle body( I figured it would get to the head?). There Is a third ground wire that appears to be coming from the Firewall where the battery would be, and it's grounded at a spot right there (clean contact)

I have a spare stock set of injectors, if all else fails I'll swap them in. as well as the TPS that is on that spare throttle body.

Is it possible that the coils are grounding out to the COP bracket? I cant quitte understand why its throwing a COIL #1 code in one of the DME's and the other DME is throwing a Camshaft Sensor Code.

I also did a smoke test and found NO vacuum leaks or any smoke protruding.


The car did sit for about a month while I did the Timing chain job.I just filled up the tank yesterday. But what Is extremely weird Is why would the problem go away temporarily If I unplug the DME and plug it back in again?

[Ryann]

Wonder if you've got a wiring issue? Grounds at the DME connector are pins 34 and 6. Google says the other end of one of those is in the group of grounds behind the RH strut tower. Also, pin 3 is batt+ from the main relay.

[fiftytakedowns]

See what was really interesting was that I was not having any trouble getting good spark from the coils, whichever coil was hooked up to number one was having a weaker spark than the other three. I checked this by pulling out all four coils and attaching them to spark plug wires which were attached to the corresponding cylinders. then I would pull the plug wire from the coil, and observe the spark arching between the coil and the plug wire. It was clearly a weaker color on cyl #1 no matter which COIL was attached.

That being said, the connector was getting a sufficient 12V to both grounds.

-Im not sure I understand how I check coil connections to places that are vs arent spupposed to be grounded.

Im getting really upset/depressed/ and frustrated with this car, I put in another 14 hours today replacing the Temp sender, the Coolant temp ssender, soaking the injectors in carb cleaner, pulling all the wires, checking for fraying checking the box under the intake plenum. testing the resistances between the DME and the coils. I also attached a large cable between the head and the block. NO avail.

What is sounding like the car is getting No fuel at all, the narrowband starts showing it going lean. I dont know what is goin on.

It's been 2-3 years having this car. and after this timing chain rebuild I did It's not even driveable. and I even double checked the cam timing. What the fucking fuck Im about to just pull this engine and go 24V or Just part it out, or sell It. Im really really feeling down.

Anyone who finds out the problem Will get a VDO gauge set that I have. as incentive.

[Ryann]

The car literally can not drive when It has not fully warmed up. it will idle (HARDLY), and will immediately Cut out/ Die / BOG if you tap the gas. This problem gets increasingly worse the colder it is outside.

Insufficient fuel pressure could cause all of these symptoms.

[fiftytakedowns]

Insufficient fuel pressure could cause all of these symptoms.

45 PSI 55 PSI without the FPR

[Ryann]

At idle? What happens to the needle when you squeeze the throttle?

This is fucked up! It really sounds like you've got a gaping hole in the intake somewhere on the head side of the TB.

[fiftytakedowns]

New hint:

I have ECu1, and ECU2.
-Start with ECU1 drive car for about a mile, misfiring occurs, first with one like quick hesitation, then it progresses to get worse, and worse.
-Pull over. pull out ECU 1, put in ECU2, (ECU2 still displays the same problem right off the bat,), pull out ECU2, put in ECU1, problem goes away until about a mile of driving...
-repeat.

OTHER symptom that may tell a lot about the problem.
-> If I can luckily Downshift to get the engine to be past 4500RPM it will not occur up there. Only misfires between 2k-4500 RPMS. IF I decelerate under 4500 rPM it will still misfire.

RYAN: It idles PErfectly fine now, and Drives fine up to about 1700RPMS, then the problem occurs. also, see above post. if the car isnt fully warmed up It will just bogg down outright, once warmed up. this funky misfiring problem occurs.