: 94 eldorado 4.6 - no codes - stumbling/chugging - about to give up



wiseman
07-08-09, 10:35 PM
Hey everyone, what a great resource. I'm frustrated, in fact, I haven't touched the car in a month. I'm not the kind of guy to give up, but I'm out of ideas. I've been through most of this forum, many posts were similar to my condition, but I didn't find anything exactly.

I'll start at the beginning. I bought the car several years ago. I thought I got a good deal. I drove it for a couple of weeks, and got stranded. It wouldn't start and fuel was coming out of the tailpipe.

I was intimidated by the car, didn't have a book, and needed transportation. I had it towed to dealer in Ft. Wayne, they changed the fuel rail for $1800. I know they saw me coming. So basically I have in the car about what is worth if it were perfect.

I got a factory service manual so I wasn't held hostage by the dealer any longer. The car started idiling high. I researched and checked, and went about cleaning the TB, and I replaced the ISC motor. I performed the learn procedure, and took the car for a test drive. About half way through it started chugging, and I limped home. Since then when I start it, it runs fine for a few seconds and then starts chugging agian. After about 5 minutes it will settle in to about a 750 RPM idle, but if I give it any gas it goes back into the chugging for another 5 minutes. Each time I give it some throttle, it repeats.

I have been through the diagnostics, and the TPS seems to be working so does the ISC motor. As I said I get no codes. I put a pressure gauge on the fuel line, and it goes up to near 49 and settles in to above 40. It seems to stay there.

I have not tried the fuel guage when the car is running, and I am hoping someone on this board can help me. Thanks. :banghead:

STSS
07-09-09, 12:06 AM
I really have no experience with this problem, but the first thing that came to mind was a plugged cat... not sure how to check...

wiseman
07-09-09, 12:41 AM
It's interesting you suggest that, because I left out the fact that during the chugging, I blew a hole in my cat. Nothing improved, but it is loud now. I was waiting on replacing it until I got the car running. I would have thought a plugged cat converter would throw codes. Thanks for the reply, and I'll look into it. I'm not sure how to check it either, but I put new mufflers on without putting a new cat converter on.:bonkers:

93sevillests
07-09-09, 01:13 AM
i too have came across this issue right now as we speak
and the guy at the dealership looked at it and told me that
the fuel rail and harness was bad and then he told me that both
where no longer available and i would need to check the salvage
yards or ebay for them
let me replace mine first and i will let you know how the outcome is

wiseman
07-09-09, 02:31 AM
Thanks STS. Good luck. I'll stay tuned.

therodman
07-09-09, 03:24 AM
Wiseman, sounds to me like you could have a shorted fuel injector. I have a 94 Seville STS and had the water pump replaced a few years back. When I was driving it home fomr the repair shop, it started to chug really bad but alos had a lot of white smoke coming out the tail pipe. Turns out when they replaced a bolt in the area where the wire bundle runs into the intake for the injectors, they crimped a wire in that bundle. I would look about 8-10 inches down from where the wire bundke enters the intake alongside the TB and see if that wire bundke is pinched, move it while running and see if runs better.

If that was or is it, it should throw a code.

I also had a catalytic converter checked one time and the fella just torched a hole in the pipe forward of the converter and held a pressure gauge in the hole with the engine running, he also did it aft of the converter, quite simple.

Good luck........

Ranger
07-09-09, 11:26 AM
It wouldn't start and fuel was coming out of the tailpipe.

If you have raw fuel running out of the tail pipe you are running extremely rich. See the tutorial in the Tech Tips section on how to check for a stuck open injector and a leaky FPR.

wiseman
07-09-09, 11:17 PM
Thanks Ranger, but that was historical perspective. That repair was done 18 months ago. I mentioned it in case it helped anyone understand my problem.
Thanks

Krashed989
07-10-09, 05:21 AM
Are you getting a good strong spark?

wiseman
07-10-09, 11:37 PM
Yes my spark is good. Get this. I had the battery out for several days, and put it back in. The car runs like a top. But I get a PO83 code. High 24V output. What does that mean? I'll go through the tests tomorrow, but I hate dealing with those clips. They are so old and brittle, plus the plugs are so secure. I always worry about breaking a wire or a connection. I appreciate all the imput and I'll post my findings tomorrow.
Thanks

therodman
07-11-09, 01:45 AM
P083 = Crankshaft to ignition module failure is what I come up with for that code. At least that's the code for a 94 Eldo, OBD1.

Krashed989
07-11-09, 06:47 AM
24 volts?!?! Your regulator on your alternator may be bad. Running it with voltage that high is a good way to fry things. The voltage itself wont hurt much, but the amps that accompany it will bring a load of heat to lay havoc to everything.

Mark C
07-11-09, 10:35 AM
I think thats an ICM code. Equivalent to DTC P0371 IC 24X Reference CKT Too Many Pulses in OBDII cars


Circuit Description
This diagnostic test checks for more than forty nine 24X reference pulses between CAM pulses. However, the number of 24X pulses is allowed to vary between 47 and 49, as long as any variances toggle between too few pulses, and too many pulses. If two variances don't toggle, i.e. they both had 49 reference pulses and 8 4X reference pulses were received between CAM events, then DTC P0371 is set because too many 24X pulses were received.

Conditions for Setting the DTC
Test Conditions
DTC P1376 not set.
At least one CAM pulse received in the last 0.25 second.
Engine speed between 496 and 3500 RPM.
Number of CAM edges since key ON is 7 or greater.
8 4X reference pulses seen between cam pulses.
Failure Conditions
More than 49 24X pulses seen between CAM pulses.

OR

The last 24X variance was 49 and current number of 24X pulses received is 49.

Action Taken When the DTC Sets

The PCM will illuminate the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.
Conditions for Clearing the MIL/DTC

The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test.
Use a scan tool to clear DTCs.
Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.

Checking for possible cause of noise (extra 24X pulses) on the 24X spark reference circuit.

If DTC resets, fault is still present. If DTC does not reset, fault has been eliminated.

Checking for poor terminal contact at the IC module or PCM that may cause the DTC to set.

Step
Action
Value(s)
Yes
No

1
Was the Powertrain On-Board Diagnostic (OBD) System Check performed?
--
Go to Step 2
Go to A Powertrain On Board Diagnostic (OBD) System Check

2
Check for possible sources of EMI (Electromagnetic Interference):

Spark plug wires run along side the Ignition Control (IC) module.
High power transmitters operating in the vicinity (such as mobile radios).
Various testing equipment.
A battery charger.
Are any possible sources of EMI found?
--
Remove source of EMI
Go to Step 3

3
Clear DTCs and retest.

Does DTC P0371 reset?
--
Go to Step 4
Fault not present

4
Check terminal contact at IC module connector C4 terminal A.
Check terminal contact at PCM connector C2 terminal 5.
Repair terminal contact if needed.
Was terminal contact repaired?
--
Go to Powertrain Control Module Diagnosis for Verify Repair
Go to Step 5

5
Replace the Ignition Control module. Refer to Ignition Control Module Replacement (Assembly) .

Is the replacement complete?
--
Go to Powertrain Control Module Diagnosis for Verify Repair
--


http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/64376-1994-eldorado-p083-code.html

wiseman
07-15-09, 04:48 AM
Krashed, sorry about the type O. The wrong finger must have moved.
Mark great information about this code. This code has flashed occasionally in the past, but went away. Does this fault explain the choppy running condition that mysteriously went away but threw no codes? Does my guess about needlessly performing idle learn procedure explain that condition?

I appreciate all your imput, and will post as soon as I figure it out.

Thanks