run kinda ok for a few minutes then it will die

[tiffseclipse]

hey all im brand new to these cars and bought a 1992 eclipse for my daughter as her first car.Its a eclipse GS 2200 motor that the PO claimed was purchased with a bad head gasket which he allegedly fixed but he couldnt get the car to stay running. he claimed it was a vacuum leak and we did notice he had the check valve in backwards which once redone it was ok
the car will start and run kinda ok for a few minutes then it will die after running worse and worse kinda missing and smoking with grey smoke and a bad smell of gas
When we first got hold of the car we noticed the spark plugs were real dirty and cruddy with black soot so those and the wires were replaced. We also noticed that the exhaust manifold had a plug on it and no O2 sensor so we replaced the manifold and the 02 sensor with ones from the junkyard car with the same motor.. it turns out the thing we put on was headers and a pipe aftermarket but not sure of the brand or manufacturer
car still runs junky and wont idle and after 30 seconds the plugs are covered with soot again
we also checked the vacuum to the fuel rail and that was ok no gas coming out there
any suggestions
to the best of my knowledge this is a stock motor with nothing else on it and it is an automatic trans

 

[DSM90AWD]

Did you check cylinder compression? After replacing the O2 sensor, did you "reset" the ECU (remove the (-) battery cable for a couple mins) to clear any stored codes?

Black plugs denote a rich condition which could be:
- Bad water temp sensor
- MAF Bad/disconnected hose connecting MAF to TB leaking
- FPR Bad
- TPS sensor bad/mis-adjusted
- O2 Sensor bad/disconnected

I suggest making a list and checking off/elimination those items you find to be ok. Also picking up a 1G datalogger (eBay) will help diagnose any CELs and tell you if certain engien sensors are functioning

 

[tiffseclipse]

thank you for the response..
I did reset the ECM by disconnecting the positive cable for at least twenty minutes and the car ran better at first then within a few moments went back to its bad idle
the MAP sensor was tested by my friend who was helping me and that proved ok
the entire time there was no CEL that remai9ned on and the way the thing started, it appears the ECM is functioning and the CEL lit for a few seconds then went out like the other cars i have that have the TBI system in it

I will look into getting the 1G datalogger and ive also asked someone who i know with a scan tool to come look at it...
Ive never had to work on an EFI vehicle before the trucks i have are all under warranty and my old one is a pre ECM 1982 chevy so this is a whole new ball of wax for me

 

[pj91gsx]

There is another way to check cel codes. You just need an ohms meter let me find you the link.

http://www.dsmtuners.com/forums/art...out-scantool-cel-testing-1g-turbo-models.html

also MAP is a manifold pressure sensor, 2gs have them, but they do not take the place of the MAS or MAF.
MAS- Mass Air sensor
MAF-Mass Air Flow
MAP-Manifold Air Pressure

MAF is the same thing as MAS. MAP is a different thing. A MAP measures pressure, a MAF or MAS measure airflow.

 

[kenamond]

These cars often seem to intentionally hide their problems from you, so throwing codes is a great thing. I'd have those read asap, as it might tell you exactly what's wrong.

 

[tiffseclipse]

i was also wondering if a clogged cat could cause this ( i havent been able to get to the car for a couple days)

 

[pj91gsx]

I think the only way to find that out is to take the cat off. My brother thought his could have been clogged but wasnt. I never heard of anyone with a cat that was actually clogged.

 

[kenamond]

i was also wondering if a clogged cat could cause this ( i havent been able to get to the car for a couple days)

The problem with checking this is that you have to battle the rusted bolts on the flange ahead of the cat which might break you first. When I upgraded my exhaust, I dropped the entire stock exhaust in one piece and then broke it apart on the garage floor with wrenches and sledge hammers. It wasn't easy, and I live in the high desert where rust isn't nearly as bad as most climates.

Have the codes read. It might tell you it's a rear O2 sensor code which indicates a problem with the cat. Or it could be something different. Any time you get a code, read it. That's what they're for.

 

[DSM90AWD]

Yea the factory CAT is a big SOB, would be hard to clog that thing.

One thing I'd noticed in your OP is that the prior owner had "supposedly" replaced the Head Gasket? Alot of people have botched a head re/re or timing belt re/re. I'd definitely check compression and that the timing belt is in alignment. Easy way to check the belt is, with the car in neutral, set the #1 cyl (closest to D/S fender) to TDC using a long screwdriver in the sparkplug hole. The two notches on the camshaft sprockets should be kissing at 3 / 9 o'clock and the timing Mark on the crank pully should be at TDC on the lower timing cover scale. If any of these are off, then the timing belt was not correctly installed.

Can also check base ignition timing, which is adjustable via the CAS mounted on the P/S of the valve cover.

Again, these are all things that may contribute to your problem. Best to check each one and eliminate if foudn to be ok

 

[viprez586]

Fuel and oil being sent through the catalytic converter could possibly destroy the cat if run for long enough. A misfire can also destroy a cat if run for long enough. Cats don't necessarily clog, more so what tends to happen is they get contaminated with excessive oil/coolant/fuel and become coated. This is not a good thing as most of you already know but what this can lead to is the elements in the cat to become exceedingly hot and melt. Catalytic converters start working at about 500F and run most efficient at 750F. If the honeycombs become loose and rotate or create a restriction the car will have a very difficult time running.

If you cannot get the exhaust out, how can you get fresh air in?
In extreme cases you could put your hand by the tail pipe and feel the exhaust "pulses" being very minimal.

Check engine vacuum with a vacuum gauge/gun.
Rasie the rpm to 2000 quickly to cause a momentarily low vacuum reading.
Then release the throttle quickly- vacuum should return smooth and decently quick to a normal level(16-20"hg). If the vacuum returns slow or is hesitant there is more then likely a restriction.

IMHO it sounds like a restriction in the exhaust, running rich and possibily misfiring aswell.

Start with the basics and keep us posted.