Continuing saga of intermittent stalls SHO 1989

[Gilbert]

Just a brief recap: SHO 1989 with about 71K miles. Recenntly had the front 60K maintenance done with change of CPS, water pump, cam and crankshaft seals, CID sensor. The car then started having intermittent stalls at 2500 rpm for brief (fraction of second to 10 seconds) and would run right after but also intermittent idle speed stalls. The motor would restart easily.

I changed the fuel pump kit for a Walbro 190 lph as was suggested which I got at APE.

The problem is still there! After the battery was disconnected, it seems to run better but the problem eventually returns. For instance yesterday I took the car downtown, I had about 8 idle speed stalls in the about 10 mile distance and 5 regular speed (2000-2500 rpm) stalls in the 40 minute drive. When the regular speed stalls occur, the rpm drops about 500 rpm very suddenly. It does not seem to matter if the motor is cold or normal. In one instance, I floored the accelerator and it revved up to 6500 rpm without strain. In another instance of doing the same, the motor seemed about to stall but eventually picked up. When I changed the fuel pump, I drove about 12 miles and the problem seemed to have disappeared but it came back... It almost seems like starting anew, after having the battery disconnected, makes things better.

I ran the KOEO codes and have the following: 59, 59, 11, 42, 95, 96, 58, 21, 42 and a few others that seem inconsistant even though I took 4 simultaneous readings. Since the front 60K maintenance, my low coolant warning light stays on even though it is well filled...

It is most annoying as I always wonder if the stall will be permanent.

Help is appreciated.

 

[TucsonSHO]

Speed sensor?

I had a very similar problem, usually downshifting in second slowing to a stop. Changed my speed sensor and all was well. Not sure how to diagnose it's integrity, but might be worth a shot.

Clovis

 

[Gilbert]

I already have a new speed sensor on hand waiting for installation. Two people, elsewhere, suggested it might be the DIS. I had a look at RockAuto that has a few models: one by Motorcraft at over 200$ and two others by AC Delco at 128.99$ for the 1989 SHO and don't know what to think... I'm getting anxious to have a proper running car as this has been going for close to 3 months now.

 

[Dr. Tweak]

Hi Gilbert

Did you change your fuel filter when you did the pump?

 

[40BelowSummer]

Two people, elsewhere, suggested it might be the DIS. I had a look at RockAuto that has a few models: one by Motorcraft at over 200$ and two others by AC Delco at 128.99$ for the 1989 SHO and don't know what to think

you can post a WTB ad and get one MUCH cheaper IMO prob $25-$50

 

[Gilbert]

Hi Gilbert

Did you change your fuel filter when you did the pump?

Yes I did install a new MotorCraft fuel filter.

What makes me wonder is when the highway stalls occur, it is much more like putting the brakes on than lifting your foot off the accelerator. IOW it is not gentle but abrupt. I've never yet tried turning the ignition off on the highway. I just might try that if there is no danger of damaging something...

 

[Dr. Tweak]

Have you done a search using each of those trouble codes, one by one? Just a thought...

 

[Gilbert]

Have you done a search using each of those trouble codes, one by one? Just a thought...

59 = Low speed fuel pump failure. I was told that when hte stall occurs, it generates it. IOW it is not causal but a result of the stall.

42 = HEGO sensor circuit idicates system rich (right HEGO). Could it cause the stalls? I had the car up and tried first to remove the old O2 sensor. Spent 20 minutes trying to get it to turn without success as I could not generate enough leverage in the cramped space underneath the car...

95 = Fuel pump secondary sirsuit failure. I guess it would be the same as for 59?

96 = High-speed relay circuit open. Same as 59 and 95?

21 = ECT sensor input is out of Self-test range???? No idea what the ECT sensor could be.

 

[Dr. Tweak]

21 Probably you didn't have the coolant up to temp when you did the test ECT=Engine Coolant Temp

I wonder if it could be that code 42... have you done a search with it? I'd also check on that code 96...

 

[Gilbert]

21 Probably you didn't have the coolant up to temp when you did the test ECT=Engine Coolant Temp

I wonder if it could be that code 42... have you done a search with it? I'd also check on that code 96...

Ever since I left your place, my low coolant level light has been on. I did add water twice right to the top. The temperature indicator is quite normal so the problem is in the sensor.

As for code 96 = High speed fuel pump relay circuit open, I have no problem getting the revs up to 6500 rpm. I have done it at least 3 times lately, in 1st gear. Am I then wrong in thinking the code is not significant in such a case? I normally don't rev that high but was most frustrated by a stall and thought it might get the gremlin out of the system... It really pulled like an SHO should! The gremlin eventually caught me back!

 

[Dr. Tweak]

Can anybody help this guy out? I got this email from him, but I don't know enough to answer. Also, could a bad ECT be causing these problems?

------
"The fuel pump and EEC relays are contained in the
integrated relay control module (IRCM) which is serviced as
a separate unit." I have no idea where the IRCM is located?

"If the ignition switch is not turned to the START position, the
timing device in the EEC module will open the ground Circuit 57
after approximately one second." So how does one identify Circuit 57?

"Ground the FP TEST pin. This should energize the FP relay in the
relay module, turning on the fuel pump in the tank." Where is that FP
test pin? "Using meter, measure at pin 5 (PINK/BLACK) of the relay
module." Where is the fuel pump relay module? I can't seem to get far
even with instructions as I can't understand what is probably
considered
the basics. While I do have a digital multimeter that I have often
used for household wiring and testing fuses, batteries, bulbs, boat
wiring (very basic two wire testing) etc. I can't seem to be able to
do much with it on the car electronics as the instructions go over my
head!
--------


If someone could give me some detailed instructions on this, I could take a ride up there and try to help Gilbert out...

 

[Venom SHO s7]

I might be able to help with the low coolant light.

If you search for low coolant light, youll probably run across a post i did where i explained how i fixed the problem in my 89 (not just by disconnecting the sensor). Apparetly the 89 was the only year that had this type of coolant reservoir tank.
If you cant find the post, PM me and ill send you the instructions.

 

[Gilbert]

Two months after my last post, I changed the IRCM in case it was the culprit with a used one I succeeded finding in California because no local junkyard had any part from 1st gen SHOs in stock. The low coolant indicator had stopped acting up by then. My problem code was still present and was fed up. Got myself a used 2004 Intrepid SXT with 11K miles on it. Sold the SHO in early December to someone who got impatient at the problem and sold it, within a month, to someone else who also got impatient at not finding someone who could find the real problem and tried reselling the car without luck... The initial symptoms started appearing in March 2004, close to a year now.

 

[SHOtimer]

All of this started after the 60k? Are you sure that you gapped the CPS correctly? Also, I would make sure all of your grounds are good, especially the DIS to the intake. I would take off the DIS, clean up the mounting surfaces good, put some now heatsink there and see how that goes. It is also possible that you have received a bad CPS, usually they have a 3 month warranty.

As for the fuel pump, I can't really help you there, as my Gen II has one steady speed.

Also, for the codes, have you cleared them and then driven it to see what reoccurs?

Doug