countpride05

I have 1989 camaro rs with a 305 tbi the car rns great when im just driving on the streets but when i get on the freeway and drive for a couple minutes the service engine soon light comes on but then goes away after the car is shut off and sits for a couple of minutes. Can anyone explain why this problem keeps repeating Thanks

quickchicken

your car is telling you something is wrong, thats why its doing this. you need to pull the codes and see what its telling you. get a paperclip and bend it into a "U" shape and then go under your dash and you will see a plug that "should" be infront of your r knee.

put one leg of the clip into the upper right plug hole and the other leg in the next upper hole. this will jumper the ECM into diagnostic mode. turn your key to the ON pos but DO NOT START. you will see your ses or check eng light start to flash.

its first flash will be a 1 count then right away followed by a 2 count. this is code 12 and is automatic. disregard this one. it will flash each code 3 times then move to the next code. when it comes back to code 12 you have seen all the codes the ECM has stored.

post up what your codes are and i or another member can help ya. from what it "sounds" like you may have a coolat temp sensor going south but we will know for sure when you pull the codes.

kd5icr

Here is a list of codes. If the mod wants he can move these or make a sticky out of it.
I have looked and I dont see a place were I could post them.

TROUBLE CODES
12. No reference pulses to Electronic Control Module (ECM).
13. Oxygen sensor signal stays lean during warm engine cruise
14. High temperature indicated at engine coolant temp sensor
15. Low temperature indicated at engine coolant temp sensor
16. High battery voltage OR Direct inition system open or shorted to ground
17. RPM signal problem
18-20. N/A
21. High voltage at throttle positon sensor
22. Low voltage at throttle positon sensor OR Fuel cutoff relay circuit open or shorted to ground
23. Low temperature at manifold air temperature sensor OR Throttle position sensor error
24. Circuit fault in vehicle speed sensor
25. High temperature at manifold air temperature sensor OR Vacuum switching valve circuit open or shorted to ground OR High voltage at ATS sensor
26. Fault in quad driver module
27. Fault in 2nd gear switch
28. Fault in 3rd gear switch
29. Fault in 4th gear switch
30. N/A
31. Low voltage at manifold absolute pressure sensor OR Fuel injector OR Park or neutral switch OR CAM diagnostic OR Governor malfunction OR Wastegate overboost OR Wastegate eletrical signal open or shorted to ground
32. Fault in barometric pressure sensor circuit OR Fault in exhaust gas recirculation valve diagnostic switch OR Fault in electronic vacuum regulator valve
33. High voltage (low vacuum) at mass air flow sensor (or MAP sensor)
34. Low voltage (high vacuum) at mass air flow sensor (or MAP sensor)
35. Idle speed can not be set to desired RPM
36. Burn off at mass air flow sensor OR Problem in transmission shift OR Fault in direct ignition system OR Missing pulses in electronic spark timing signal
37. N/A
38. Fault in torque converter clutch brake switch
39. Fault in torque converter clutch circuit
40. N/A
41. Fault at cam sensor OR Cylinder select error OR Tach input error
42. Fault at electronic spark timing circuit OR Fault at direct ignition system OR Fault at fuel cutoff relay circuit
43. Low voltage at electronic spark timing circuit
44. Oxygen sensor lean
45. Oxygen sensor rich
46. Fault at vehicle anti-theft sytem OR Fault at power steering switch
47. Problem at Electronic Control Module (ECM)
48. Misfire
49. Vacuum leak
50. N/A
51. PROM error
52. Problem at Electronic Control Module (ECM) - Missing fuel calpac missing OR Analog to digital converter error OR Fault at quad driver module OR Low voltage at oil temperature sensor
53. High voltage at battery OR High voltage at exhaust gas recirculation valve OR Voltage reference error OR Problem at vehicle anti-theft system
54. Low voltage at fuel pump OR Low voltage at Fuel pump relay OR Output failure at quad driver module
55. Problem at Electronic Control Module (ECM) - ECM failure OR Serial bus error OR Fuel lean malfunction
56. Low coolant or corrosivity OR Fault in port throttle system vacuum sensor
57. N/A
58. Problem at vehicle anti-theft system
59-60. N/A
61. Oxygen sensor degraded OR Port throttle system error OR Cruise control problems
62. Gear switch input diagnostics OR High voltage at oil temperature sensor OR Fault in cruise control- vacuum solenoid circuit
63. High voltage at manifold absolute pressure sensor OR Fault in exhaust gas recirculation valve OR Fault at right oxygen sensor
64. Low voltage at manifold absolute pressure sensor OR Fault in exhaust gas recirculation valve OR Right oxygen sensor lean
65. Failure at exhaust gas recirculation valve OR Faulure at injector peak/hold diagnostic OR Right oxygen sensor rich OR Fault at cruise control position sensor
66. Internal reset of Electronic Control Module (ECM)
67. Fault at cruise control switch
68. Fault at cruise control switch
69. Fault at air conditioner pressure switch
70-87. N/A
88. Internal reset of Electronic Control Module (ECM)

BabyD

I Haney the same car and from what it sounds like had the same problem. If you pull off the air filter and look on the left hand side you should see a cable coming out of a rectangle cut out. It is the air intake temp sensor. If it is touching metal (or shorting out by touching metals) it will douse the light to come on. I made a wall type barrier out of electrical tape to keep it away from metal. This took care of the issue for me. Hope his helps.

countpride05

Ok well i got the codes for my car but i don't know how to read it the light flashes three times then a short pause then two flashes and a long pause and repeats it self.. does anyone know what that means?

mako350Z28

My old 92 Z28 flashed that code at me once...I would have to point my finger at a faulty EGR valve.

quickchicken

thats code 32 which is EGR. your best bet is to purchase a HELM book from ebay and NOT the hays book. the HELM book is for YOUR YEAR ONLY. the hays book is 1½ in thick and covers 82-92. the helm book is 2 1/4 thick. thats alot of missing info with the hays book.

the helm book will direct you thru the fix it process.

BigBadLou

32 is what I suspected, it usually shows up on the highway under partial load but then disappears.

As instructed here previously, a good manual helps with troubleshooting.
Though the EGR system is very simple, it consists of 4 parts only: 2 vacuum hoses, 1 electric solenoid and 1 vacuum diaphram valve.
And you are lucky, too. The EGR system on the TBI engines is very easily accessible and serviceable, compared to TPI for example.
If you follow the troubleshooting diagram in the service manual, you will know what's wrong with the EGR system shortly. It could easily be a vacuum hose that popped off by accident, it could be a burnt out solenoid, it could be the EGR valve itself that plugged up with carbon deposits and needs to be cleaned.

Let us know what you find.
Lou

tom2

Ran into this once. Did it once in a while, then got more frequent. I took off the EGR valve and the vacuum port in the intake was all gummed up. I punched it out and got it opened up, problem solved. If your engine has a lot of miles on it, might be the same deal.