Help my Chevy s10 keeps dying!


#1

Ok, here?s the situation. I have a 1986 Chevy s10 pickup 2WD automatic with 115,000 miles on it that I drive occasionally. For about a year now the pickup has been dying on me approximately one second after I step on the gas after stopping at a stoplight, stop sign, a crosswalk, or just to let a gaggle of geese cross the road. The result of this is that everyone in the pickup lurches forward into their seatbelts as the power disappears and we have to coast, or limp at a very, very rough 100 RPM or so, to the curb. Then I have to turn the pickup off and restart it and it usually starts back up and runs perfectly for a while before it does it again although once in a while I have to start it up two or three times before it will run well. This makes taking left hand turns across a lane of oncoming traffic after coming to a stop especially exciting. One more odd thing about this problem is that it only happens after the pickup is very warm, and has been driven for 45 minutes or more. I took the pickup into a local shop and although they experienced the problems, they could not diagnose what was wrong. Unfortunately after I got the pickup back from the shop it died 3 times at stop signs on the way home and once in the middle of a road as I was driving without stopping, so the problem is getting worse! The shop told me that they think it is probably a problem with the ECM, which gets extremely hot?too hot to touch, but they couldn?t be 100% sure because only an authorized GM dealer has the machine to test an ECM. The authorized GM dealer wants to charge me 87 bucks just to diagnose the problem, on top of a $300 new ECM, if that is the problem, as well as labor?the truck is 21 years old and I don?t have an extra 500 bucks to spend on it. So I am asking you, car geniuses, what do you think? Is it the ECM? If so I can buy one from a junkyard for 70 bucks or so and install it myself (it?s just unplugging a wire harness right?). Or is it something else? Please let me know what you think. Thanks.


#2

Has anyone checked to see if there are any error codes store in the car’s computer? You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code not just their translation into English and post it back here. It likely will have a format like P1234.


#3

[b]Your vehicle has the OBDI engine management system. So any codes pulled will not be a PXXXX code. Those pertain to OBDII engine management systems. Instead the code numbers for your vehicle will be a two or three place numerical code. But you can pull the codes yourself on this vehicle.

Locate ALDL connector under the dash below the steering column. Insert a jumper wire between the A and B terminals. Turn the ignition to the RUN position. The Check Engine light will start flashing codes. The first code will be a code 12, and will repeat three times. It will show up as *-**. Where a * equals a flash and - equals a pause. This code means the engine management system has gone into the diagnostic mode. If this code never shows up, there’s a problem with the ECU. Any other codes will follow the code 12 and each will repeat three times.

You have to remember that the OBDI engine management system monitored only a few perameters. It isn’t as sophisticated as the OBDII engine management system. So, you might not get a code for a component even if there’s a problem with it.

But there is one thing you can do with an OBDI management system that can help determine the problem. And that is unplug a sensor when the problem occurs. When this is done, the engine management system will operate on a default value. So, if you unplug a sensor, and this causes the problem to be less severe or disappears altogether, you can assume there’s a problem with that sensor. Of course doing this is going to turn on the Check Engine light. But simply disconnect the negative battery terminal for 15 seconds to turn the light off. Then try the next sensor.

Tester[/b]


#4

Your advice sounds great but according to Autozone, who would check the error codes for free, if there is no check engine light on (and there isn’t) the reader won’t get anything from the ECU. Is this true? If so any other ideas (it does sound like an ECU problem so maybe just get a used one?)? Or will the ECU still give me info (and I should take it down to Autozone and plug it in). Let me know. Thanks.

N8


#5

Your advice sounds great but according to Autozone, who would check the error codes for free, if there is no check engine light on (and there isn’t) the reader won’t get anything from the ECU. Is this true? If so any other ideas (it does sound like an ECU problem so maybe just get a used one?)? Or will the ECU still give me info (and I should take it down to Autozone and plug it in). Let me know. Thanks.

N8


#6

The ECU may be the problem but I doubt it is. One thing you could do to check that is install a small 12 volt muffin fan, like a computer power supply uses, near the ECU to keep the heat level down.

I would suspect the real trouble to be with the throttle position sensor or MAF sensor connection. Also possibly the fuel pump relay.


#7

The ECU should be the cheapest thing on the truck, about $100 or a little more. Get a remanufactured one that is from Sorensen. Some mechanics say not to get it at NAPA. Especially replace it if it is solid state, as in being able to see the old style transistors and things. You don’t have the service engine now light coming on, but you should. To test it; after the malfunction, disconnect the battery and reconnect it. If it reboots, it may go a couple days before it happens again. Then change it. I’m really not authorized to test ANYTHING, but I had a similar problem with an 85 Cadillackackack. A really powerful battery seemed to help the Caddy, but not a real lot. It just made the failures a little less frequent.


#8

The new computer comes with instructions. You have to take the prom chip out of the old one, real easy job. Prom chips are expensive but they almost never go bad. If you know where the ecm is, you’re halfway there. Ignore most of the complicated instructions that make you say “what the heck are drivers anyway”. If the weather is really dry, you might want to hose down the parking spot you are in to reduce the chance of a static spark, when you are installing the computer. It’s all easy stuff.


#9

I had a similar thing happen to my 86 s-10. I change the idle control switch( if that’s what it’s called -actually is the switch which is behind the throttle body on the left side with the square plug ) It cost me arounrd $58.00 @ advance auto part store.


#10

The part is called the IDLE AIR CONTROL VALVE. It’s behind the throttle body on the left side.

NOTE: FOLLOW THE INSTRUCTIONS VERY CAREFULLY


#11

I have a 99 S10 and this EXACT same thing has been happening to me for the 5 years I’ve had it. Every mechanic in Tucson thinks Im NUTS!!! It happens to me in the winter (when its 60 here) and in the summer (when its 110) as well as early in a trip (2 minutes) or late in a trip (2 hours). I have not been able to find ANY pattern.

I did go to an Autozone and got a code of P0122 (I think) which is the Throttle sensor thing. They said it was $38 to buy the part and only a couple of screws to fix. I hope it works. I would love to hear from you all. Ill post a response post-installation to see if that helps at all.