1990 SC will start then immediately die
- Thread starter Joe1990SC
- Start date
found out why it wont start
I did a check on fuel and spark, spark is good but i checked at the fuel injectors with a noid light and bingo!!! it is cutting fuel, It does have good fuel pressure about 40 psi. so my question is which sensor controls fuel injectors??
Thank you.
I did a check on fuel and spark, spark is good but i checked at the fuel injectors with a noid light and bingo!!! it is cutting fuel, It does have good fuel pressure about 40 psi. so my question is which sensor controls fuel injectors??
Thank you.
TbirdSCFan
Registered User
Injectors are a straight shot from the EEC. Its possible its a wiring issue. You might try reseating the connectors around the pass side firewall, and across the engine.
Reply
All the injectors are new, But when i replaced them now that i think about it I think i did forget to reattach the ground wire behind the fuel rail. but even before then when it was running rough not good but running it was doing the same thing the fuel injectors were working intermittently. which the reason for the rough running now that i remember back but during that time i thought it was a bad sensor.
Is it possible the ECM is going out???
All the injectors are new, But when i replaced them now that i think about it I think i did forget to reattach the ground wire behind the fuel rail. but even before then when it was running rough not good but running it was doing the same thing the fuel injectors were working intermittently. which the reason for the rough running now that i remember back but during that time i thought it was a bad sensor.
Is it possible the ECM is going out???
>Is it possible the ECM is going out???
Run
the
codes
...again, if that's what it takes.
Report back what you find.
Then, grab the Engine/Emissions-Diagnosis 1990 Shop Manual, pg. 2-2 Diagnostic Routine Index / Gasoline Engines, starting w/routine 202 'Cranks Normally But Won't Run (Stalls)', working thru 207, perhaps, depending on what you find.
Run
the
codes
...again, if that's what it takes.
Report back what you find.
Then, grab the Engine/Emissions-Diagnosis 1990 Shop Manual, pg. 2-2 Diagnostic Routine Index / Gasoline Engines, starting w/routine 202 'Cranks Normally But Won't Run (Stalls)', working thru 207, perhaps, depending on what you find.
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"If you don'a eat your meat, you can'na have any pudding...how can you have any pudding if you don'a eat your meat!?"
There you go.
KOEO codes, if there were issues that system could sniff:
- EEC 19
- Fuel 87, 95, 96, 542, 543, 556 (not sure 3 digit codes apply to a '90).
Don't chase ghosts, don't throw parts at it, don't guess. Re-connect that ground wire before you start condemning stuff. I find it easier to do that from below, BTW. Just remember the order of the stack on the stud, not that the order is critical, but if you end up fighting it, that may help re-attachment.
Did you replace the balancer?
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Did you disconnect the cam sensor and try to get it started/make it run that way? Might take more than one try to get it to fire, so don't give up on the first go.
House call...nice - but only if they know these cars
The KOEO code for it is 22
>22 O,C,R Manifold Absolute/Baro Pressure Sensor out of range
House call...nice - but only if they know these cars
The KOEO code for it is 22
>22 O,C,R Manifold Absolute/Baro Pressure Sensor out of range
With nothing concrete to suspect either the cam or baro sensor, your mechanic can rule them out. Both of you are just guessing at this point, and w/an SC, that can go on forever.
It's not that easy - I mentioned resistance for a reason. One path might be fine with one size wire of a given length and insufficient with another that was fatter and not the same length, simply trading one problem for another. Current flows on the surface of a wire, not down the middle like water thru a pipe. If you use a wire/connectors that are too small, you risk higher resistance. Don't do that. With a short/thick wire, area is more and length is less. With a long and thin wire, area is less and length is more - the long/thin wire will have higher resistance.
I'm not keen on endorsing a risky fix/patch job. I'd like to see the factory ground wire re-connected at the stud on the back of the head.
Again, for now, add a test ground, say to the battery, with a decent sized wire (8 ga?) and see what happens. I'd not get overly creative with the wiring on an SC, tho, so be sure any changes you make are the right ones.
I have not found a way to test a crank sensor off the car, but since I have just solved a slightly similar problem on my 92, I'll ask this...
When you changed the DIS, did you use lots of fresh heatsink compound on the bottom? Those things get really hot really fast and when they do the engine misbehaves. My 92 would run like it was missing, then stall and not start after warming up, and then upon trying to restart the upshift light would be on which made me think crank sensor even though it only lit up on trying to restart, not when starting cold. So I replaced the crank sensor but it made no difference.
I replaced the DIS and used lots of heat sink compound and it's been perfect ever since.
I've since put the old crank sensor on another SC and it works fine.
Another thing....you said you replaced the injectors. Did you replace with the exact same model or where they a little different design? Particularly the nozzles....
When you changed the DIS, did you use lots of fresh heatsink compound on the bottom? Those things get really hot really fast and when they do the engine misbehaves. My 92 would run like it was missing, then stall and not start after warming up, and then upon trying to restart the upshift light would be on which made me think crank sensor even though it only lit up on trying to restart, not when starting cold. So I replaced the crank sensor but it made no difference.
I replaced the DIS and used lots of heat sink compound and it's been perfect ever since.
I've since put the old crank sensor on another SC and it works fine.
Another thing....you said you replaced the injectors. Did you replace with the exact same model or where they a little different design? Particularly the nozzles....
Reply
The injectors are the same, tested with a noid light at the injector connerctors and the pulse while cranking and when it was running while cold is intermittent or no pulse at all granted it wasnt as bad while it would run while cold but now its worse then before. when i replaced the DIS i used all the compound it came with, I dont think it has overheated, since it was doing this before with the old one.
The injectors are the same, tested with a noid light at the injector connerctors and the pulse while cranking and when it was running while cold is intermittent or no pulse at all granted it wasnt as bad while it would run while cold but now its worse then before. when i replaced the DIS i used all the compound it came with, I dont think it has overheated, since it was doing this before with the old one.
So now it runs like crap all the time, hot or cold?
Did you put a light on the crank sensor to watch it while running? Maybe it's intermittent also...can't think of anything else that would cause intermittent injector firing if it still starts.
I think you said in your original post that it wasn't running right since you got it? How long did it sit before you got it?
Did you put a light on the crank sensor to watch it while running? Maybe it's intermittent also...can't think of anything else that would cause intermittent injector firing if it still starts.
I think you said in your original post that it wasn't running right since you got it? How long did it sit before you got it?