Redou

[Redou]

hello,

Am working on my buddies '89 Cutlass Ciera, 2.5 L, automatic, TBI single injector.

He's elderly and living on $7200 / year SS so doesn't have much $$$ to throw parts at this problem.

1) about a month ago, car overheating, fan would not come on,

I changed out his rotten radiator for a new one, installed new
coolant temp sensor, idled engine until electric fan came on, seemed OK, then put a bic lighter to the Coolant Temp Sender and made sure idiot temp light come on in dash. Problem fixed. Now he has a new Problem:

2) Mornings turned chilly (less than 60 degrees F in Louisiana is considered chilly) - and now his '89 Ciera 2.5 runs rough while engine is cold. He said it did the same thing last year - "just not as bad"

Engine never fails to start but stalls out, shakes, spits and occasionally backfires back up the throttle body, and will not idle when engine cold. He has to keep his foot in the gas pedal to keep it going. After 2 to 10 minutes the engine seems to warm up and smoothes out and runs fine.

There is a transition period between running crappy and fine
where he is getting some mild misses out the tail pipe.

Once the Ciera is warm and running good he can drive around
fine but if he stops it for more than about 1/2 hour he has to go through the extended (and very rough) warm up to restore normal engine function. Outside temp at this point is about
80 degrees. Ciera (once warm) runs great down highway at 70 mph. Plenty power, acceleration good.

When engine is cold and running rough:

- tailpipe smells rich and you can smell unburnt gas.

- fuel injector is spraying cone shaped pattern but is intermittent and plugs show a little black dry carbon coating. However extended running after warm up shows tan plugs looking normal.

- turned key on and off several times, fuel pump pressures up
each time and with engine off - no signs of dribbling or leaky injector

- disconnected injector with engine running good / warm. Fuel flow stopped and engine quit. No signs of fuel leaking from injector.

- Ran hot air into air cleaner housing with my girlfriends hair dryer to warm up throttle body and get warm air to MAT - no change in problem start up.

First codes generated were: MAT , TPS, CTS

MAT - showing -31(minus 31) degrees temp. I installed new MAT - backprobing Mat shows constant voltage to sensor and good ground.(with KOEO)

TPS - TPS shows constant voltage to sensor and good ground.
(with KOEO) - TPS backprobing shows apparently normal
voltage change when throttle position is changed

CTS - new CTS installed when radiator was changed out. Backprobing shows good voltage to CTS and good ground (KOEO)

I checked all vacuum holes to intake, can not hear any vacuum leaks, plugged holes one at a time, tightened intake and TBI bolts, blocked off EGR passage. I disconnected fuel injector
and hooked Vacuum gage to intake. Shows 4 inches of Mercury when cranking cold. At warm idle Vacuum gage shows 18 inches of Mercury.

Don't think it's a vacuum leak.

Buddy says plug wires were changed 3 years ago. Removed them one at a time. Ohm meter said 20 ohms (longest wire) then 15 ohms then 10 ohms apiece on the shortest two. All connections seem tight and plugs all show tan color. Engine runs great , does not miss, when warm.

O2 sensor (single wire) threw no code and shows voltage after engine gets warm.

Disconnected battery to clear ECM, warmed up engine until it
ran smooth, drove it around. Codes now are MAT and Idle
Air Control. Voltage good to Idle Air Control and good ground. Car idles fine after engine warm, will not idle cold.


KOEO - Electric Cooling fan goes on and off intermittently
whether engine is warm or cold - you can hear injector clicking intermittently. Engine is not overheated.

Found muffler was damaged - possible exhaust restriction - but engine shows plenty power when running warm down the highway, accelerates good.

The only code generated more than once is MAT. Has apparently generated both high and low readings.

Sorry for the long post, looking for some fresh ideas.

Any help appreciated.

Redou

[maxwedge]

You need a real scan and look at what temps the ecu sees for the mat and ct sensors.

[Redou]

Thanks, Maxwedge, for your reply.

I called O'Reilly's Auto Parts, they have a scanner (code reader?) for $25 or will rent one (refundable) for $200. I suspect I need the $200 scanner? I'll go rent it Monday and get readings on Mat and Ect and post them here. Thanks again. Redou.

[D Ryan]

Its sounds like your going through the same problem as Msattler in this post:

http://www.automotiveforums.com/vbul....php?t=1014248

I'm in the same boat with you.

Stay on it!

[Redou]

Hello,

I'm still trying to figure out the problem. 1989 Cutlass Ciera
2.5 L TBI single injector. Engine runs very ROUGH when
cold, backfires out the Throttle body, smell of too much
gas out the tail pipe. Runs fine when it warms up.

Thanks for your replies.

To Maxwedge - I rented the "scanner" from O'Reilley's Auto Parts ( $264 ) - hooked it to the OBD I plug and found it is merely a code reader. It said that there are now no codes, same as I got from the CEL flashing light.

I don't know where to get a 'real scan' - the GM dealer?

However, there is a new development.

I found that, after focusing on the engine and sensors and finding no reason for cold rough running that:

If I simply leave the Key ON engine Off for 10 minutes, the engine starts and runs normally - avoiding the VERY ROUGH
warm up period.

When the Key is turned on - cold engine - the electric cooling fan cycles off and on intermittently and the TBI single injector clicks intermittently for a couple of minutes, then they stop. I believe I can also hear a relay clicking. After another 7 or 8 minutes with Key On Engine OFF the engine will start and run smoothly.

My buddy says when he went to the store, the Cutlass 2.5 sat in the parking lot for 30 minutes. He had to leave the key on for
about five minutes before it would start normally even though
the engine should still be warm. It's 80 degrees here.

Something seems to be making the computer cycle cooling fan and injector intermittently KOEO. I thought it might be low or intermittent voltage to the computer.
The battery shows 12.2 volts after sitting all night.
The ECM fuse shows a steady 11.8 volts KOEO engine cold.
I boosted the battery with a stronger battery.
Hooked together they showed 12.6 volts.
Now the ECM fuse shows a steady12.0 volts KOEO with engine cold.
The engine started and ran rough cold.
The extra voltage seems to make no difference.
After leaving the KOEO for 10 mins it started up and ran fine.
After it ran for 5 minutes, shut engine down.
Now battery shows 12.4 volts - ECM fuse (in fuse box) shows
12.2 volts with only original battery hooked up after some
charging by alternator.
Whenever engine is running and alternator kicks in - ECM fuse
shows 14 steady volts.


To D. Ryan,
Thanks again for your input. I read the post you suggested carefully and checked the fusible links with an Ohm meter. They all read OK and show no signs of corrosion. My buddy's
car troubles now appear to be wiring / electronic rather than
sensors / mechanical so checking fusible links perhaps eliminates one possible source of trouble.


Whatinthehell should I check next ??

Regards, Redou

[maxwedge]

Again, a scan will look at the coolant temp inputs and air intake temp inputs as well as other parameters, get a mechanic at a shop to do this or buy a real scanner, These cars will not set a code easily like obd11, the scanner must work on OBD1 remember.

[D Ryan]

Originally Posted by Redou

Hello,

I'm still trying to figure out the problem. 1989 Cutlass Ciera
2.5 L TBI single injector. Engine runs very ROUGH when
cold, backfires out the Throttle body, smell of too much
gas out the tail pipe. Runs fine when it warms up.

Thanks for your replies.

To Maxwedge - I rented the "scanner" from O'Reilley's Auto Parts ( $264 ) - hooked it to the OBD I plug and found it is merely a code reader. It said that there are now no codes, same as I got from the CEL flashing light.

I don't know where to get a 'real scan' - the GM dealer?

However, there is a new development.

I found that, after focusing on the engine and sensors and finding no reason for cold rough running that:

If I simply leave the Key ON engine Off for 10 minutes, the engine starts and runs normally - avoiding the VERY ROUGH
warm up period.

When the Key is turned on - cold engine - the electric cooling fan cycles off and on intermittently and the TBI single injector clicks intermittently for a couple of minutes, then they stop. I believe I can also hear a relay clicking. After another 7 or 8 minutes with Key On Engine OFF the engine will start and run smoothly.

My buddy says when he went to the store, the Cutlass 2.5 sat in the parking lot for 30 minutes. He had to leave the key on for
about five minutes before it would start normally even though
the engine should still be warm. It's 80 degrees here.

Something seems to be making the computer cycle cooling fan and injector intermittently KOEO. I thought it might be low or intermittent voltage to the computer.
The battery shows 12.2 volts after sitting all night.
The ECM fuse shows a steady 11.8 volts KOEO engine cold.
I boosted the battery with a stronger battery.
Hooked together they showed 12.6 volts.
Now the ECM fuse shows a steady12.0 volts KOEO with engine cold.
The engine started and ran rough cold.
The extra voltage seems to make no difference.
After leaving the KOEO for 10 mins it started up and ran fine.
After it ran for 5 minutes, shut engine down.
Now battery shows 12.4 volts - ECM fuse (in fuse box) shows
12.2 volts with only original battery hooked up after some
charging by alternator.
Whenever engine is running and alternator kicks in - ECM fuse
shows 14 steady volts.


To D. Ryan,
Thanks again for your input. I read the post you suggested carefully and checked the fusible links with an Ohm meter. They all read OK and show no signs of corrosion. My buddy's
car troubles now appear to be wiring / electronic rather than
sensors / mechanical so checking fusible links perhaps eliminates one possible source of trouble.


Whatinthehell should I check next ??

Regards, Redou

Find that relay you hear clicking, it should snap an thats it.!!!!!!!!!!!111

I had a few suggestions thrown at me to try, I think something is draning voltage from ign feed at B+ @ computer, mine reads 5.3 and it runs, at 4.7 it dies, so the first place im going to disconnect the heated ox sensor and see if there a change in the voltage, in my car there are about 6 different things that get power from circut 639., from there i'm going to ign stw/net safet stw,

I have a 95 cutlass cirra 3.1 sfi and like you its bad when it first starts (mine throws a code po431, cam sensor) but after it warms up i'm good to go, the light on the dash will stay lit until the next key cycle reguards
less of running condition.

You might try this. disconect battery, work key stw back and forth about 100 time the clean slid connectors off abit. Worth a try!!!!

keep us informed
Denny
St Louis

attchment may be diffrent from yours

Uploaded with ImageShack.us

[D Ryan]

Originally Posted by Redou

Hello,

I'm still trying to figure out the problem. 1989 Cutlass Ciera
2.5 L TBI single injector. Engine runs very ROUGH when
cold, backfires out the Throttle body, smell of too much
gas out the tail pipe. Runs fine when it warms up.

Thanks for your replies.

To Maxwedge - I rented the "scanner" from O'Reilley's Auto Parts ( $264 ) - hooked it to the OBD I plug and found it is merely a code reader. It said that there are now no codes, same as I got from the CEL flashing light.

I don't know where to get a 'real scan' - the GM dealer?

However, there is a new development.

I found that, after focusing on the engine and sensors and finding no reason for cold rough running that:

If I simply leave the Key ON engine Off for 10 minutes, the engine starts and runs normally - avoiding the VERY ROUGH
warm up period.

When the Key is turned on - cold engine - the electric cooling fan cycles off and on intermittently and the TBI single injector clicks intermittently for a couple of minutes, then they stop. I believe I can also hear a relay clicking. After another 7 or 8 minutes with Key On Engine OFF the engine will start and run smoothly.

My buddy says when he went to the store, the Cutlass 2.5 sat in the parking lot for 30 minutes. He had to leave the key on for
about five minutes before it would start normally even though
the engine should still be warm. It's 80 degrees here.

Something seems to be making the computer cycle cooling fan and injector intermittently KOEO. I thought it might be low or intermittent voltage to the computer.
The battery shows 12.2 volts after sitting all night.
The ECM fuse shows a steady 11.8 volts KOEO engine cold.
I boosted the battery with a stronger battery.
Hooked together they showed 12.6 volts.
Now the ECM fuse shows a steady12.0 volts KOEO with engine cold.
The engine started and ran rough cold.
The extra voltage seems to make no difference.
After leaving the KOEO for 10 mins it started up and ran fine.
After it ran for 5 minutes, shut engine down.
Now battery shows 12.4 volts - ECM fuse (in fuse box) shows
12.2 volts with only original battery hooked up after some
charging by alternator.
Whenever engine is running and alternator kicks in - ECM fuse
shows 14 steady volts.


To D. Ryan,
Thanks again for your input. I read the post you suggested carefully and checked the fusible links with an Ohm meter. They all read OK and show no signs of corrosion. My buddy's
car troubles now appear to be wiring / electronic rather than
sensors / mechanical so checking fusible links perhaps eliminates one possible source of trouble.


Whatinthehell should I check next ??

Regards, Redou

Check out page 4 , your battery charge is not up to task.
http://www.roddingroundtable.com/for...=108264#108264

Keep us informed, I'm going after ign stw today!

[Redou]

Hello,

89 cutlass ciera - 2.5L -TBI - runs bad at Cold Morning start

-runs OK after extended (ROUGH) warmup

-runs OK if you leave Key On Engine Off for 10 mins before
starting.

-I pulled the computer out (ECM) - took it apart
- all connections look
good - studied it with a magnifying glass - no signs of trouble
from visual inspection.

- If I hang the computer - still tethered to it's 2 plugs - out of
the glove box hole - warm computer up for 1 minute with a
girl's blow dryer - (warmed it up on the side where PROM
is located ) - car starts fine on a cold morning and
runs smooth. Tried it 5 times at various cold morning
temps. Works every time.

- I don't know if it's the PROM or the ECM that's bad...


I told my buddy he can carry the pink hair
dryer around in his car and an extension cord with him but
he doesn't like that idea for some reason, So:

- Planning to buy a new computer, but I can't get the PROM
out to put it in the new computer.

The plastic cover/ cage it sits in is clamped down
somehow. The book says to move the 2 (two) retaining
clips "away from the PROM" and "using 2 fingers" - gently
pull PROM out. - I'm missing something. The retaining
clips on top hold the PROM down tightly, moving them
does not release the plastic cover/ cage that the PROM sits
in from the socket.

- how do you get the dam thing out without busting it?

Thanks for your time, any input will be appreciated.

Redou.

[D Ryan]

Originally Posted by Redou

Hello,

89 cutlass ciera - 2.5L -TBI - runs bad at Cold Morning start

-runs OK after extended (ROUGH) warmup

-runs OK if you leave Key On Engine Off for 10 mins before
starting.

-I pulled the computer out (ECM) - took it apart
- all connections look
good - studied it with a magnifying glass - no signs of trouble
from visual inspection.

- If I hang the computer - still tethered to it's 2 plugs - out of
the glove box hole - warm computer up for 1 minute with a
girl's blow dryer - (warmed it up on the side where PROM
is located ) - car starts fine on a cold morning and
runs smooth. Tried it 5 times at various cold morning
temps. Works every time.

- I don't know if it's the PROM or the ECM that's bad...


I told my buddy he can carry the pink hair
dryer around in his car and an extension cord with him but
he doesn't like that idea for some reason, So:

- Planning to buy a new computer, but I can't get the PROM
out to put it in the new computer.

The plastic cover/ cage it sits in is clamped down
somehow. The book says to move the 2 (two) retaining
clips "away from the PROM" and "using 2 fingers" - gently
pull PROM out. - I'm missing something. The retaining
clips on top hold the PROM down tightly, moving them
does not release the plastic cover/ cage that the PROM sits
in from the socket.

- how do you get the dam thing out without busting it?

Thanks for your time, any input will be appreciated.

Redou.

The plastic cover/ cage it sits in is clamped down
somehow. The book says to move the 2 (two) retaining
clips "away from the PROM" and "using 2 fingers" - gently
pull PROM out. - I'm missing something. The retaining
clips on top hold the PROM down tightly, moving them
does not release the plastic cover/ cage that the PROM sits
in from the socket.

I think the key here is that you do them at the same time!!!!!!!

Push the clips to clear and pull , at same time!!!!!!!!!!

Nice trick with the hair dryer, I.m going to try it!

The info I have is that the board has internal breakers, maybe one is stuck and your heat trick is changing that.
I wonder what you might see if you had the key on and probed the board with a eraser end of a pencel with no lights on. might be broken solder joint. Might see a spark!

You might do a amp draw on different circuts, see what changes after 10 minutes.

You said somthing earler that bothers me! The fan coming on with eng cold, thats not right! You also said a relay was clicking! Was it the fan relay? If the relay is shorting it may heat up(feel it) and expand and the short may go away! If thats what happening it could be triping the internal breaker. Your hair dryer trick kinda bolws this theory away though!

Can you start the car and it run good from cold temp if you did the hair dryer thing and not the key on for 10 minutes??????????????

[D Ryan]

[quote=Redou;6836042]Hello,

89 cutlass ciera - 2.5L -TBI - runs bad at Cold Morning start

-runs OK after extended (ROUGH) warmup

-runs OK if you leave Key On Engine Off for 10 mins before
starting.

-I pulled the computer out (ECM) - took it apart
- all connections look
good - studied it with a magnifying glass - no signs of trouble
from visual inspection.

- If I hang the computer - still tethered to it's 2 plugs - out of
the glove box hole - warm computer up for 1 minute with a
girl's blow dryer - (warmed it up on the side where PROM
is located ) - car starts fine on a cold morning and
runs smooth. Tried it 5 times at various cold morning
temps. Works every time.

- I don't know if it's the PROM or the ECM that's bad...


I told my buddy he can carry the pink hair
dryer around in his car and an extension cord with him but
he doesn't like that idea for some reason, So:

- Planning to buy a new computer, but I can't get the PROM
out to put it in the new computer.

The plastic cover/ cage it sits in is clamped down
somehow. The book says to move the 2 (two) retaining
clips "away from the PROM" and "using 2 fingers" - gently
pull PROM out. - I'm missing something. The retaining
clips on top hold the PROM down tightly, moving them
does not release the plastic cover/ cage that the PROM sits
in from the socket.

- how do you get the dam thing out without busting it?

Thanks for your time, any input will be appreciated.

Redou.[/quot

Was wonderin what the out come was if any?

I havent tryed the hairdryer trick yet, if it gets any colder around here Ide have to resort to a torch. LOL!

[Redou]

Looks like problem is solved.

Waited for the car to run good for a while before I said
it is fixed.

The PROM in the computer, variously identified as a Mem- Cal and or Prom just pulls straight out but seemed stuck. Put more pulling pressure on it than I wanted to
but it wouldn't come out. I was scared of breaking it.

I hooked the tip of a sharp pointed knife just along the
edges where the lower plastic socket cover meets with
the upper plastic Prom / Memcal cover and GENTLY
pried them apart on the ends only. When one end came
up, the other wanted to go back down - so I put a wooden match in the gap and kept prying- alternating
ends .

After a while it came loose.

I cleaned the soft silver-colored contacts on the Prom/
Mem-Cal with electrical contact cleaner and also the
flexible springy gold plated contacts of the socket.

At least I think they are gold plated, little corrosion and
a gold color. They are bendable, so I slightly bent them
outward (away from the socket) on both sides with a needle. Now they would make stronger contact with the silver colored contacts of the Prom.

Put the PROM back in. The book says it is supposed to
snap into it's socket but it doesn't.

Apparently corrosion and or temp shrinkage were to blame.

The car hasn't missed a lick since. The colder temp the
better it runs.

Got lucky this time.

Thanks for everyone's input.

It's great that this forum exists, fresh ideas are the best
tonic for frustration.

Redou.

[Redou]

Just wanted to post that car starts and runs fine - now
going on two months - in case someone else has the
same problem.