Crossfire help
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Joined: Oct 2015
Posts: 63
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From: Dallas, Texas
Crossfire help
I know there have been many pots on the subject, but I was hoping to get some help on my 82 collectors edition. It runs for about 20 seconds then dies. It does this same thing every single time, time after time. I cant drive it at all. I hooked up a timing light, and the timing bounces all over the place. I can never get it set to 6 BTC or anything really. I have done checks for vacuum leaks, replaced coil, cap, ignition module. The only code it throws is 12 and that is normal. I really hate throwing parts at it without really knowing whats the problem. The car only has 28,000 miles on it and has been a top flight NCRS car for years.
Safety Car
Joined: Nov 2005
Posts: 3,532
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From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
I know there have been many pots on the subject, but I was hoping to get some help on my 82 collectors edition. It runs for about 20 seconds then dies. It does this same thing every single time, time after time. I cant drive it at all. I hooked up a timing light, and the timing bounces all over the place. I can never get it set to 6 BTC or anything really. I have done checks for vacuum leaks, replaced coil, cap, ignition module. The only code it throws is 12 and that is normal. I really hate throwing parts at it without really knowing whats the problem. The car only has 28,000 miles on it and has been a top flight NCRS car for years.
Now for a hint on timing. Did you disconnect the EST wire before you started to check the timing? If not, and you start turning the distributor, the ECM is still controlling the timing and you will NEVER be able to set the timing properly. All you want to do is check base timing anyway and set it at 8* - 10*. I know, the book says 6*, but you can go 8-10 as long as the motor doesn't ping. The GM Shop Manual is your best friend on a 35 year old car.
Also, like mentioned... CFI motors are rather fuel pressure sensitive. You need to know where your FP is set. Check it and set it to 13psi and you'll be happy with the results on a stock motor. OBTW, that's in the manual as well.
Last edited by Buccaneer; Apr 10, 2017 at 02:25 PM.
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Joined: Oct 2015
Posts: 63
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From: Dallas, Texas
Great ideas for sure. Yes I did disconnect the ECM wire before trying to set the timing. As for fuel, the injectors are are both spraying an umbrella shaped patterns. In fact it seems to me that the car is running very rich. I have not checked the fuel,pressure yet, as I am not seeing a lack of fuel. I will do a fuel pressure check next!!!! Thank you everyone��������
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Thread Starter
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Joined: Oct 2015
Posts: 63
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From: Dallas, Texas
Sorry for the delay on this. I did a fuel pressure test and it holds a steady pressure of 8 poiunds. I understand it needs to be 11-13 pounds, correct? So I should replace the fuel pump? Would it be best to use the 82 fuel pump or a later year pump?
Thanks all!
Thanks all!
Le Mans Master
Joined: Jul 2000
Posts: 6,664
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From: columbia city in
you need a pump .I have had a 85-87 pump for 20 years .no problem.but others will say only use the 82 pump .if you use the better pump keep a eye on your thottlebodys for leaks . the added pressure can put a strain on the old gaskets.
Team Owner
Joined: Jan 2006
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From: Crossville TN
If you put a later version pump on your car, you will also need to install a pressure regulator to keep from blowing the seals out of those throttle-bodies. I'd stay with the '82 pump...unless it is more expensive that the later version PLUS the regulator.
I had an '84 car which had exactly the same engine/transmission as the '82. I remember a similar problem with mine. It turned out that the airflow sensor heated wire had collected a lot of dust/etc. on it and that acted as insulation, keeping the wire from cooling due to airflow and making the ECM think it wasn't getting enough air. That caused it to lean-out and the engine would die. It ran just long enough to go into "auto" mode, then died.
Hope that's all it is for you, too. (Take big duct off the front of the sensor, then carefully brush off the sensor wire. Replace duct.)
I had an '84 car which had exactly the same engine/transmission as the '82. I remember a similar problem with mine. It turned out that the airflow sensor heated wire had collected a lot of dust/etc. on it and that acted as insulation, keeping the wire from cooling due to airflow and making the ECM think it wasn't getting enough air. That caused it to lean-out and the engine would die. It ran just long enough to go into "auto" mode, then died.
Hope that's all it is for you, too. (Take big duct off the front of the sensor, then carefully brush off the sensor wire. Replace duct.)
Le Mans Master
Joined: Jul 2000
Posts: 6,664
Likes: 162
From: columbia city in
If you put a later version pump on your car, you will also need to install a pressure regulator to keep from blowing the seals out of those throttle-bodies. I'd stay with the '82 pump...unless it is more expensive that the later version PLUS the regulator.
I had an '84 car which had exactly the same engine/transmission as the '82. I remember a similar problem with mine. It turned out that the airflow sensor heated wire had collected a lot of dust/etc. on it and that acted as insulation, keeping the wire from cooling due to airflow and making the ECM think it wasn't getting enough air. That caused it to lean-out and the engine would die. It ran just long enough to go into "auto" mode, then died.
Hope that's all it is for you, too. (Take big duct off the front of the sensor, then carefully brush off the sensor wire. Replace duct.)
I had an '84 car which had exactly the same engine/transmission as the '82. I remember a similar problem with mine. It turned out that the airflow sensor heated wire had collected a lot of dust/etc. on it and that acted as insulation, keeping the wire from cooling due to airflow and making the ECM think it wasn't getting enough air. That caused it to lean-out and the engine would die. It ran just long enough to go into "auto" mode, then died.
Hope that's all it is for you, too. (Take big duct off the front of the sensor, then carefully brush off the sensor wire. Replace duct.)
https://en.m.wikipedia.org/wiki/MAP_sensor there is no wire to clean.the regulator is in the rear throttle body
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
Your response clarified my memory. It was NOT my '84 C4 that had that problem...it was an '85 Olds Cutlass Supreme (3.8L) with that problem. Sorry. At the time I read your post, my [30-year-old] memories went to that C4...MEMORY ERROR!
Last edited by 7T1vette; Apr 21, 2017 at 10:49 PM.
Safety Car
Joined: Nov 2005
Posts: 3,532
Likes: 1,185
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
).
Melting Slicks
Joined: Nov 2005
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From: Leonardtown Maryland
Rich gassy smell, good fuel injector pattern, runs for a few seconds? Classic throttle position sensor problem. Check it with jumper wires and a multimeter. Do a search and you will find procedures and results. Good luck.
Fuel pumps also go bad. There are replacement pics and procedures on the forum too. Recommend doing a complete job by installing new ethanol resistant fuel injection strength hoses throughout the system. You will probably need to drop the gas tank to do that.
Fuel pumps also go bad. There are replacement pics and procedures on the forum too. Recommend doing a complete job by installing new ethanol resistant fuel injection strength hoses throughout the system. You will probably need to drop the gas tank to do that.
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Joined: Oct 2015
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From: Dallas, Texas
Hi all
Finally got the new fuel pump installed, shows 12-13 lbs of pressure on the gage. Car barely ran, and was not even close to drivable. On a hunch I pulled the computer from the battery compartment and swapped out the PROM chip. That has solved the problem from what I can see from several test drives today. Looks to me that a previous "mechanic" bent a couple of the PROM pins. Thanks for everyone's input...you just never know!
Finally got the new fuel pump installed, shows 12-13 lbs of pressure on the gage. Car barely ran, and was not even close to drivable. On a hunch I pulled the computer from the battery compartment and swapped out the PROM chip. That has solved the problem from what I can see from several test drives today. Looks to me that a previous "mechanic" bent a couple of the PROM pins. Thanks for everyone's input...you just never know!
