89 randomly sputters and dies

[jonnylocke]

Hello all, this is my first post here!

 

I have an 89 with 112k miles that runs and drives so smoothly... until it doesn't.

 

The problem first started while I was sitting at a red light and the car started sputtering and fluctuating RPM. I was sitting around 650-700 then it would sputter and drop below 500 for a second, jump back to ~700, and back and forth for a bit before eventually dying after a few sputters. I threw it in neutral and tried to restart the car and it just sat and cranked without starting. I eventually got it back running with it sputtering badly, followed by it lunging forward and dying as I put it in gear and pressed the gas pedal. I started it again and was able to get it moving to get out of the way. This was on a hot July/August day, and I recall it running fine the rest of that day.

 

A few days later, it died while I was sitting in stop and go traffic. Similar sputtering, dying, trouble restarting, then eventually seemed completely fine. It did this routine a couple more times here and there, but only when at stop or extremely low speeds. One day, it happened as I was pulling out pretty hard from a stop. The car rocked back and forth from it accelerating, feeling like the engine stopped, then accelerating like that back and forth until it just died at around 25-30 MPH.

 

I originally thought it could be clogged injectors, so I put the recommended amount of injector cleaner (Marvel Mystery Oil) in my next tank of gas and ran the engine pretty hard that day. No luck.

 

I was about 500 miles from home on a trip when all of the above happened, so I didn't have much I could try due to not having tools with me. When I got it home (notably with 0 issues on the trip), I told my dad about what had been happening, so we started trying some things (he's worked on cars as a hobby for 30+ years and has been able to take care of pretty much every issue all of our Reatta's have had for the 5 years we've owned them).

 

We checked grounds, cleaned connections, cleaned the IAC, checked the pressure on the fail rail with a gauge (I believe it read about 40 PSI). No luck. I had to leave to go to work, so I took a different Reatta and left him with the problematic one.

 

He remembered having to change the coil pack when we got the car a few years back due to a different issue. He checked the coil pack, no issue. He visually inspected the ICM and it was pretty bad. We posted about it on a Facebook Reatta group, most all of whom said the ICM was shot and recommended us to upgrade to the 3-coil design. We bought an ICM and new coils from RockAuto and the ICM they sent was bad, making the car run very rough and instantly throwing an E042 code upon starting. My dad found an ICM on a mid-90's Riviera at a junkyard that worked beautifully when put on the car with the new coils we bought. The car ran smoothly and he didn't have any sputters or dying for the 200 or so miles he drove in the 4 weeks he had it. I went home to pick it up, drove it the 200+ miles to where I live, and it was beautifully smooth.

 

The next day, I drove it to work, and the car sputtered a couple times while pulling out from a red light. It did not die, and it was fine right after and for a couple days after. A couple days later, it died in a drive-thru without any warning sputters, and it was hard to start back. A day later, sputtered and died at a red light. Most recently, it repeatedly sputtered and died in a parking lot at low speed and took 2-3 tries to restart each time.

 

Additionally, a weird thing I'm noticing about the car on the highway is that it runs perfectly when the gas pedal is pressed, but if I let off the gas to coast, it feels like it misses every couple seconds or so. The stutters/misses are so small the RPM gauge doesn't catch most of them, but one time it did refresh right as the stutter happened and the RPM had dropped by 100 (it was like 1700 down to 1600 or so). The car kinda jolts me forward in the seat a little from slowing down a tiny bit when these microstutters happen.

 

This leads me to believe that 1. the ICM wasn't the problem, 2. the ICM wasn't the only problem, or 3. this ICM isn't good and just played nice for a bit. I'm 200 miles away from my dad's tools and have only a small set of tools, so I can't go too in depth troubleshooting and working on stuff. Dad said the spark plug wires look new and he believes the previous owner changed the spark plugs & wires about 20k miles ago. Perhaps the spark plugs actually are bad? Maybe the fuel injectors are going out? I'm running out of things to think to try and replacing the fuel injectors isn't something I can just take $50 and try, it's looking to break $200 easily and potentially hitting $300.

 

A few last things to note that I didn't know where in the story to place them: 1. this car has been a little harder to start since around the time I bought it. Of our 3 running Reattas, 2 start up practically instantly (cold or hot) and this one takes a second or two. Sometimes it even takes two key turns before it will start. 2. Cam magnet fell off and threw an E041 code a couple years back. Car ran kinda similarly to now while the magnet was off. We glued it back on and the car was fine after. 3. The issue is intermittent and only seems to happen after it has at least run for a bit and become warm-ish. Even the microstutter when coasting doesn't seem to happen until the car hits a solid 170 or 180 F.

 

Thank you for any and all replies!

 

EDIT: Forgot to mention car idles pretty rough often when its hot.

Edited November 9, 2021 by jonnylocke
Added detail

[Ronnie]

Welcome to the forum! Good to see another Tennessee resident here. Do you have any codes stored in diagnostics?  Has this car ever had the crankshaft position sensor replace on it?

[jonnylocke]

I've checked the ECM codes many times, logging what is there, then resetting it to keep a log of what pops up and when. The only E code I have had for this specific issue is E042, and it only popped when the RockAuto ICM was on it.

 

To my recollection, I don't believe the crank pos sensor has been replaced on it.

 

EDIT: I texted my dad and he says we have not replaced the crank sensor, but he pulled one from the Riviera when he got the ICM.

Edited November 9, 2021 by jonnylocke

[2seater]

I agree that replacement of the crank sensor may be indicated. I found this the hard way too, it normally fails and stays failed but I had one that operated much like described. Frustrating to find when it seems to self heal. If fuel pressure is good, can you watch one sensor at a time in diagnostics? Thinking something else may be failing but still working and giving bad information. The MAF sensor comes to mind.

[Ronnie]

I'm not a Reatta expert but if it were me I would carry a fuel pressure tester so you can check the fuel pressure on the spot when it sputters and dies before restarting the engine to rule that out as the problem.  You saying it is harder to start than the other cars has me leaning toward the fuel pump as being the problem. Read through my recent post about my fuel pump problems and you will see some similarities to the problem you are having.

 

The crankshaft position sensor most of the time will just go bad and the engine won't start again but I've heard of them doing as you describe is happening to your car.

 

The MAF sensor can cause similar problems as you describe too. Try unplugging the MAF driving to see if the same symptoms continue as before or change. The check engine light will come on but driving it with the MAF unplugged won't hurt the engine

[Ronnie]

Looks like 2seater and I were posting at the same time and are pretty much in agreement.

[jonnylocke]

Thanks for the replies everyone!

 

I am currently at work and, on my drive here this morning, I had the RPMs pulled up on service mode. As I mentioned in the post, the RPM gauge wouldn't keep up with the stutters I noticed. However, service mode did. I was holding about 1600 RPM while coasting w/o throttle, which would drop below 1200 when the stutters happened and jumping right back up to ~1600.

 

Another first, the car died during one of those throttle-less stutters today while at ~40 MPH. Luckily, I got the car into a safe area, took a couple tries but it came right back up and got back to speed with no problem.

 

I will try unplugging the MAF on my lunch break and seeing what happens.

Edited November 9, 2021 by jonnylocke
chose a better word

[Ronnie]

34 minutes ago, jonnylocke said:

... service mode did. I was holding about 1600 RPM while cruising w/o throttle, which would drop below 1200 when the stutters happened and jumping right back up to ~1600. ...

Was the cruise control engaged or are you saying the RPM was holding at 1600 with your foot off the throttle?

[jonnylocke]

Cruise was off, I let go of the throttle once I reached speed, saw that the car was coasting at 1600, then would randomly drop to below 1200 before jumping right back to 1600.

 

Sorry, "cruising" was a bad word choice

[2seater]

There is a programmed Deceleration Fuel Cut Off that is normal under certain conditions. When coasting down, it cuts fuel off to reduce emissions. I don't know what the exact conditions are offhand, but the momentary drop in rpm can can be normal. That said, the engine should not quit altogether.

[Ronnie]

Another thing that can happen during deceleration is opening and closing of the EGR valves. There are three openings in the EGR that are individually controlled with solenoids by the ECM. Perhaps one of them is sticking causing the engine to die when decelerating or idling. You can do some tests in the onboard diagnostics you could do to determine of the EGR solenoids are working properly.

[jonnylocke]

Hi all,

 

My apologies for not responding in a couple days, I've gotten busy at work and caught up with other things when I'm off.

 

The stutters when coasting w/o throttle feel pretty large, unlike anything I've experienced in the three Reattas we own. Even in this one with the issue, when its cold it doesn't have the coasting stutter, and I don't recall it having the stutter before the main issue started a few months back.

 

I go on lunch in about 5 minutes, I will try unplugging the MAF, as I don't see anything holding me up today.

 

On second thought, might have to wait again on trying the MAF. I went outside and its raining pretty hard.

Edited November 11, 2021 by jonnylocke
its raining

[jonnylocke]

Alright, so I drove home with the MAF unplugged last night and the car performed pretty much identically. Stuttered while coasting, stuttered a couple times while accelerating from stop, etc.

 

How do I try the EGR thing in diagnostic mode?

[2seater]

In override mode while parked you can cycle the three solenoids to see what the reaction is but I don't believe they can be overridden while driving. I am not as familiar with the touch screen but I believe you can only see if the ECM is calling for EGR with a symbol on the screen while driving. Rough idle and other symptoms might indicate a leaking EGR and the only way I know of to bypass is to place a block off plate under the valve itself. 

[DAVES89]

You have two other Reattas. I would swap an ignition module coil pack from one to this one. 

[DAVES89]

I will share an experience I had been having with my Black '88 Reatta. It started with ignition. Sometimes it would start instantly like it should and sometimes it woud grind for a second or two and then fire, Sometimes it would catch and run and sometimes not and I would try the starter again and it would then catch and run.

While this was going on I would have "accelerator" issues where I would put my foot into it and the car would just take off and not stop accelerating unless I would take my foot off the gas and then hit the accelerator  and then it seemed to release and the RPMs would drop back down and run correctly. This seemed to correct itself as I went into another faze.

The last couple of weeks I would get a bucking when I would try to accelerate from any speed almost like the car couldn't breath because of a clogged cat converter. I knew that wasn't it as the exhaust is new. I thought maybe MAF sensor and swapped in another one. No change.

So I swapped in another Magnavox ignition and same issues only worse, so I knew it was the ignition module. Swapped in the Delco ignition Module/Coil Pack and all the issues are gone.

Car starts quickly, doesn't "rev up",  and no bucking. And the benefit is the Delco unit has higher output so it actually seems way quicker then before. 

Well worthy doing...

[jonnylocke]

Hello all, happy 2022!

 

With the holiday season past us, I am finally free enough to work on the car again. Yes, it is still doing everything I said in the original post.

 

The bad news is, we took the Magnavox-style ICM and Cam Magnet Sensor from a car we know is fine and put it on this car and had no luck. Car still died after it was warm and had idled for 30 seconds or so.

 

We also put a fuel pressure gage on it to monitor, we got 42 when priming ignition, about 34-36 when idling, and about 38 when it would die. So 99% sure it is not the fuel pump, filter, or regulator. 

 

I tried the EGR override Ronnie and 2seater mentioned and both the 3 and 2 override in ECM diagnostics would make the engine shutter then regulate RPM to what felt like 500 or so. EGR 1 would not have much of a noticeable effect when overridden, it might idle a bit lower but still pretty normal.

 

One thing to note, every 10th time it dies (give or take) it will start back oddly and throw an E042 code with check engine light on. It will run a lot less smooth with much less power, but I've yet to have it die when the check engine light is on with an E042. I read a little into it and it says it is running on bypass spark. Not sure what that means but it does not seem to ever die when on it, just runs like crap.

 

The only things in my mind are fuel injectors and spark plugs, but the E042 code has me curious what it could mean.

 

Thanks again for the replies thus far, and I hope to stay more active on the forum now that the holidays are fully over!

Edited February 20, 2022 by jonnylocke
Clarified a few things

[DAVES89]

By your posts you have not yet changed the crank sensor. At least check the gap. Take a business card and cut a 3/4" strip from it the long way, fold it over towards one end so it doesn't fall through and use it as a feeler gauge on the crank sensor to check your gap. After everything else you have done, I think your problem lies there.

[2seater]

It seems E042 keeps surfacing in this thread. As far as I understand, that is the ECM control of the spark and ignition timing. It seems there may be a communication issue with the ECM. I am not very familiar with the harness routing on an 89, IE, where does the connector to the ICM come from. At the least I would try disconnecting, contact cleaning and reinstalling the three connectors on the ECM. 
 

The crank sensor was mentioned a while back but it seems it may never have been installed?

 

oops, looks like Dave has that covered👍

Edited February 20, 2022 by 2seater

[Padgett]

The ICM connector has very short pins. I always remove the sponge when reinstalling and the single screw does not tighten evenly. Try removing the sponge and tappong on the ends of the connector when tightening.

 

I wound up building a break out box from scrap so I could monitor the ICM connections.