Tired of working on this car... Miss in engine

IGot6UGot8

Registered User
I've been working on an '89 SC that started out running fine, just had a bad water pump. I figured I'd change motor mounts, plugs, wires, and the crank sensor while it was apart. Got it all done, and fired it up and took it around the block. The engine seemed to be missing pretty bad, so I double checked all my connections and firing order (123, 564). Took it back out and no change, except that the check engine light came on at about 5psi in 2nd. I checked codes and came up with 21, and 54. So I looked at the crank sensor and thought maybe it was a little too close, so I readjusted and tried again. SAME THING. So I put my old crank sensor back on thinking I may have fried the new one somehow (old one should be good, I just changed them cause I was down there). Now it's still rough, but I'm getting the following codes 21, 54, 24, 77, and 74. I checked spark at the "coil" and am getting strong spark on all cylinders. I'm stumped. I'm trying to get the car running good so I can sell it, after buying my '95 SC.

If anyone has any ideas or suggestions.. they'd be realy appreciated.

Thanks
Jake
 
Wow Jake I understand It get old going over the same old areas with no change.

Well from the codes you gave you were doing a KOER test something I have yet to experiance. Or was it a KOEO test if it was disregard codes 74 and 77 I think you have to push the brake and the foot feed during a test at the correct time and you did not.

Codes 21 you need a new ECT (engine coolant temp sensor) or have a bad connection . 24 and 54 are the same ACT (air charge temp sensor) need a new ACT or bad connection. This could be the problem the EEC need this info to send the correct amount of fuel to cylinders.


The ACT is on the inlet plenum next to the nipple for the boost gauge. The ECT is on the lower intake manifold sticks up by the ignition control module (DIS).

Do you have a EGR there is some good info in the FAQ forum to see if the EGR is working
 
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If it was me having that problem, I would start from the beginning of where I started to remove wires/hoses/connections/etc. and make sure that all the connections that I took off are back where they should be. If the problem wasn't there before, more than likely it is caused by something you did by trying to fix it. I can't count how many times I was trying to "fix something myself" and wound up spending more time trying to find out what I messed up while trying to "fix" some other problem! If you read all the forums about doing to motor mounts yourself, I think I read where it was a good idea to take pictures from many angles so that you could put everything back. If you did that, I would take a look at those pictures and compare. If you didn't, find a picture of a similar year engine and make sure all the connections are hooked up in the right places. I hope you don't get too frustrated! You might need to get away from it for a while and come back to it with a calmed down attitude. Many a member on this board have written about how walking away from a problem was the best thing that they did, because when they came back to it, the solution to their problem hit them like a ton of bricks all within a matter of minutes! Good luck!
 
Thanks for all the advise... I'm a huge fan of "if it aint broke..." but as hard as things are to get to in these cars, I thought it would be a good idea to change the regular "maintanence" items while I could get to them. Also, I've had 2 of these cars taken apart a few times, and pretty much know where everything goes. I have double and triple checked all the connections that I had off, and some that I hadn't even touched. Is there some way to individually test the ECT and ACT sensors? BTW, I did both KOER, and KOEO tests... the only codes I got with under KOEO were 21 and 54. And I definately have to agree with the walking away theory.. my wife has to remind me of that one often.

Thanks again
Jake
 
Jake I know exactly how you feel but just walk away from the car and work on it at a different time. Hope you have another car to drive. This has happened to me on several occasions and I did not even look at the car for months. Hope everything works out for you.
 
isnt the firing order 1 4 2 5 3 6 (123 , 456) ???

he said it was 123 , 564 (1 5 2 6 3 4)

am i wrong or what?


3.8L Engine
Firing Order: 1-4-2-5-3-6
Distributorless Ignition System
 
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No Darkstar you are incorrect, Firing order IS 123 564.
Maybe your hanging out too much with a Chevy..:D
 
maybe im hanging out too much with your mom...

how come on the chilton manual book it says..

1 4 2 5 3 6

riddle me that batman
 
Because the Chilton manual is wrong. If you would read posts on this subject here, you would have read that the firing order was found to be incorrect on the CHEAP manuals. Go buy yourself a good manual like the Helms and stop stepping over the line. If I were BobGPZ, you'd get an earfull from me. I just hope for you sake you know the guy.
 
I think you're right about the firing order, as far as when the cylinders actually fire off. the 123, 564 I was referring to is the way the wires are placed on the coil pack. I do have another car to drive, 3 other cars, but that doesn't make it any less frustrating. I'm sure I'll figure it out... even if I don't, I can make my money back out of the car by parting it out. I could use some of the parts for my '95 anyway.

Thanks
Jake
 
Bob which one is it. I always thought the firing order was 153 426

Odds then evens. Wow am I confused.

The coil pack says

123
564

so in what sequence do the cylinders fire?
 
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well I don't know. Gonna have to hook up a noid light and watch it I guess.

I think two spark plug wires fire at the same time. wasted spark so when it sparks right on the compression stroke the other fires on the oppsite on the exhaust stroke. somthing like that If I ever figure it out all let you know.
 
Not that I think this is what's wrong with the guy's car who started this thread, but here is a diagram with the correct info.



PlugandWireLayout.jpg


David
 
1 4 2 5 3 6

that is what it say on the lower intake manifold. So which plugs fire at the same time. So which plugs fire oppisite of each other. which are the ones that are on the same coil circuit. That whole wasted spark thing. Do 1-4 spark twice then 2-5 sparks twice then 3-6 twice or how does it work? .The reason we have to use PP plugs is because of wasted spark so which are working together??????
 
Do me a favor

check the hose going from the driver side valve cover to the air cleaner tube,my car had amiss and this was the culprit .Like my daddy used to say" check the simple **** first"
 
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