Jump to content

Engine still dies randomly


Guest Recian

Recommended Posts

Guest Recian

Well after fighting with it all week im kinda stuck as to what to do next. My 89 still dies going down the road for no reason whenever you let off the gas. It only does it in drive not neutral and doesnt do it sitting in the yard. Today when I cranked it, it still idled at 2000+ which it's been doing since I adjusted the TP sensor to .40v After i turned the key off and back on after idling a few mins and the temp gauge reading it idled about 800 but acted like it wanted to die. I wiggled the wiring and tapped the sensors on the t-body with no effect. I uplugged the MAF and it's idle smoothed out and it ran like it was designed. So since that was my "good" maf I went to the auto store and got a new one. It ran great, idle stayed consistant. I was like sweet it's fixed! Went for a drive and it started to sprinkle.. then rain then pour then the windows started to leak and it died again and again and again more consistantly than ever before so I tried to be hard on it keep the rpms up and get it home.. not easy with traffic wanting to turn and not being able to see in the rain. About 1/2 way almost 2 miles to go it overheats for no reason just to make things worse... Im just clueless where to go now, if I should look at the idle valve or the coil pack because sometimes it kinda sputers when cranking fr a few seconds, never an excessive crank time and when you try to restart it after it dies going down the road you gotta give it gas or it dies again sometimes. During the incident AIR FLOW readings stay consistant about 4.9-7.0 and TP stays at .40, no spikes or jumps. Any ideas?

Link to comment
Share on other sites

Guest Recian

that was my old one. I have yet to check readings on the new one. Im just curious if it's a bad ICM. It doesnt sputter or give warning it dies just as if you turned the key off but everything inside doesnt turn off.. unless there's a short in the ign switch or could the ED 41 cause it? I think it's 41 it's the sensor inside the timing cover that was covered in another post for a short cut to replace it. Also I read some other posts on ronnie's site about a similar problem and i didnt know the ICM grounds through the bracket it's bolted to. Possibility that it's losing ground randomly, maybe the engine ground which would keep the ICM and the coils from seeing a ground and causing the engine to die. I'd think plugged cat too but that would make it die sittin in the yard.

So far i've replaced the MAF, plugs/wires, cleaned the IAC (forgot to clean the housing. may be it?) adjusted the TP sensor (which seemed to have a big effect until today)

Edited by Recian (see edit history)
Link to comment
Share on other sites

Guest Recian

not yet. Ill check it b4 heading to work tomorrow. It or a dirty IAC housing is my prime suspect. I have another one from another 89 i parted out in the junkyard I may stick on there and hope for the best. Spent the last of the car money atm hoping the maf would fix it when i need it to fix my hyundai's rear suspension. tires are showing cords due to worn struts now :( .. and the maf fixed my idle conscerns and stumbling but not my stalling issue

Link to comment
Share on other sites

Crankshaft Position Sensors are notorious for causing stalling problems like you have when they first start going bad. ICM can do the same thing. Sometimes you can see the gooey stuff coming out which is a good sign of an ICM on it's way out. Since the ICM is much easier to change I would rule it out as the source of the problem before changing the CPS. Neither one will set a code when they go bad.

Link to comment
Share on other sites

Time you took a full snapshot of the ECM values when it is acting up, something is obviously rong. When it "overheated" was it just the gauge or was it really hot ?

Reason I ask is that I have seen a bad coolant sensor act this way (high idle warm, over rich cruise, stalling). Do you get any black smoke out the tailpipe when acting up ? Overrich can also foul the O2 sensor.

Took ECM readings from white car, (just driven). Keep in mind that I have retuned for lower temperatures and slightly higher idle for better a/c.

White Car, just back from drive, at idle 23 June, 2011

84F OAT, A/C on.

Sorry, all of mine are rePROMed, Delco ignition. 87 PON gas.

1 TPS .40

4 COOL 83*

6 IPW 5.5-5.7

7 O2 VARIES

8 SA 20

10 BV 13.5

11 RPM 730-760*

12 MPH 0

16 ESC 0

17 OPA3 182

18 CC 0**

19 FI 128

20 BLM 128

21 MAF 6.5-6.6***

22 IAC 60-62***

23 MAT 50

*- reprogrammed PROM

**- common at idle

*** - idle set 10% higher than stock so IAC and MAF will be a little higher.

Edited by padgett (see edit history)
Link to comment
Share on other sites

First I did not read the last post on this, but here is my two cents.

TCC! Torque Converter Clutch! It is a fairly cheap part. but take a while to put in. I have seen two people junk cars due to this. It locks in and then will not release from its position until power is removed. Like turing the key off or to start position.

Link to comment
Share on other sites

On a different tack, have you checked the fuel pressure regulator? Check the little vacuum hose for any signs of fuel. When mine was bad, symptoms were that the engine ran fine in open loop, but as soon as closed loop it would sometimes stall and become hard to start. Basically the FPR was leaking unmetered fuel into the intake through the vacuum hose and invalidating the sensor readings.

Link to comment
Share on other sites

Guest Recian

that's the thing, if it's fuel pressure or TCC it'll sputter and die. This is a straight up cut off as if the engine's spark or fuel was cut instanly with absolutely no warning. Its hard to monitor ECM data when it happens because of the lack of warning. Only reason i dont suspect fuel pump or TCC is #1 if it was fuel it would sputter as it uses up the fuel that's still in the rail and have a hard to start after it dies cuz it has to re-pressurize and it cranks back up and fires just gota give it some gas or it'll die again #2 it does it going down the road maybe 35-45mph so if TCC engaged it'd just lower the rpm not kill it since the car's moving

Edited by Recian (see edit history)
Link to comment
Share on other sites

Guest Recian

icm is clean. no goop or even residue. Im leaning towards CKP sensor because it was terribly bad yesterday in the rain. I could barely keep it running. The ckp is by the crank pulley which is open to all water and dirt coming off the road since it's on the bottom of the engine so if rain makes it worse maybe that sensor is going bad. It uses a photo diode to pick up signal off the reluctor on the back of the crankshaft pulley doesnt it?

Link to comment
Share on other sites

a) I believe the CPS uses magnetic pickups rather than photo just like the ABS and Cam Sensor.

B) What you do is to prime the system for the snapshot mode and then just touch/push the "yes" button to take it when the transient happens. Once you have it, pull over and record the values. Might need to repeat. A lot of engineering is repetitive testing like this.

c) if there is a problem with the CPS, I would expect the tach to be erratic.

d) BTW most scan tools have a similar capability. I have a software tool that will take a new snapshot (and store sequentially) every time you hit the space bar. Another will take continuous snapshots on every frame until the disk is full or you tell it to stop.

Keep in mind that on every frame (a few times a second, never bothered to measure) the ECM sends a complete set of the readouts in a serial data stream on the ALDL. Scan tools just read that data stream and display the parameter of choice but all are sent every frame.

On of the first things an engineer of the sixties did in a new facility was to find a long, relatively unused hallway where the Brush recorder paper could be unrolled on the floor so you could walk up and down looking for abnormalities in the traces.

Edited by padgett (see edit history)
Link to comment
Share on other sites

Totally off the wall... did you check the battery connections including the ones behind the battery on the fender wall? From what I have read, as it has never happened to me, is that when the Crank Sensor goes bad it puts you in a "limp" mode. There have been a number of writeups regarding the bolt to the battery causing a poor connection as well as the leads in the positive and negative lead boxes behind the battery being bad...

Alls I'm saying is that if you are experiencing a sudden cut out it is probably electrical. Might as well start with all the connections as that is the cheapest place to start first.

Link to comment
Share on other sites

Guest Recian

i have checked my connections and even the engine grounds. Im positive it's something electrical. Ive seen alot of posts on this same problem that has been fixed by battery connections exept for one problem. My engine dies only. My gauges and everything stay on. If the steering wheel didnt get stiff and pedal stopped responding you'd never know the engine quit. The tach isnt erratic, just goes to 0 going down the road. Idk if the tach goes to 0 because the engine died or because it lost the signal which led to it dying. They happen at the same time. Im cruising at 45, 1800-1100 rpm depending if im touching the gas or not for TCC and next thing i know the gauge reads 0

Link to comment
Share on other sites

Tach going to zero is a good indicator the system lost its primary crank reference - could be the CPS, ICM, or wiring.

Have you tried replacing the short crank and ignition harness ? The single screw 14 pin ICM connector is also known to be sometimes problematic, might try removing the rubber pad inside the connector.

Just looking at cheap things (R&R all connectors) before replacing electronic parts but sounding like a damaged CPS.

ps if in lockup, it is like a manual transmission being in gear. You may lose power but the engine will not stop turning. Tach suddenly going to zero (not slowly dropping) is a clue.

Edited by padgett (see edit history)
Link to comment
Share on other sites

Guest Recian

yeah the tach suddenly goes to 0 with no warning. you may see 1800 -500 -0. (since it's digital reading through the touch screen)That's what's making me think crank or icm or connection to these components. I know if i keep my foot on the gas it wont do it and it wont die just sitting in the yard running. It doesnt sputter either. Just dies as if you cut the key off. Even if you cut the key off with it running holding it at 1800 it does the same thing 1800 - 300-500(ish) -0. I have a spare icm from a junk car i may try. the connector to the icm is dirty but i havent looked at it inside at the pins yet. Knowing gm products it could be corroded to s**t

Link to comment
Share on other sites

Pins in ICM connector are also short, why I have had to remove the pade before to get a little more engagement. I sla push on the ends when tighening to get every last bit. Do not rely on the screw to pull in fully.

Link to comment
Share on other sites

... I have a spare icm from a junk car i may try.
I don't mean to sound rude but considering all the discussion that has taken place in this thread about the ICM routinely causing the stalling problem that you are experiencing, and you seeming to be anxious to fix this problem, I'm surprised that you wouldn't just go ahead and change it. It's no more than a 15 minute job.
Link to comment
Share on other sites

Guest Recian

im going to tonight. I started the thread last night and i get up at 6 to drive 1hr to work and i dont get off til 6 and drive another hour home so from 6am to 7pm i cant work on it, just a couple hours a night. I just wanted to bounce some ideas first so i've got ideas to use when i do get time to fix it. With it dying randomly i cant drive it to work. once i get that fixed i will

Link to comment
Share on other sites

Agree & might as well upgrade to a Delco. Point I was making is that it may be the fault of the connector, not the ICM but swapping a different ICM may fix the problem if the connector makes a better connection i.e. the problem may be the connection and not the module.

Link to comment
Share on other sites

Guest Recian

Got home earlier and took off the ICM, it still had the rubber seal inside and it wasnt super tight (the bolt) The bracket it was on was painted too. It had been removed to paint the bracket at one time. The bracket from what i know grounds the ICM through it's housing so I sanded the corrosion off the icm and sanded the paint off the bracket and re-tightened the icm and connector without the rubber seal inside and went for a long test drive.. with no stalls! :) went about 5-10 mile range and it was terrible last night in a 2 mile loop so im 95% sure it's fixed

Link to comment
Share on other sites

Guest Recian

that's what i did after. My spare coil has goop coming out so it's toast. It has a spare connector on it should I have issues down the road with it again

Link to comment
Share on other sites

that's what i did after. My spare coil has goop coming out so it's toast. It has a spare connector on it should I have issues down the road with it again
You should start looking for a good used Delco ICM/Coils as Padgett suggested the next time you are at a junk yard. Then keep yours for a spare. Check out Padgett's webpage for more info. He has lots of other good Reatta info on his site that you should become familiar with.
Link to comment
Share on other sites

Guest Recian

that's very usefull info and it helped me diagnose another problem. I know the coil is bad too because as he mentioned on that page is the coil pack can cause a low rpm sputter which mine has. You have to gve it a good bit of gas taking off or it sputters like it wants to die. Gota get looking for some delco coils. A trip to youngs may fix that since the yard is over 100 acres of cars and 70% GM

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...