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I have a 1990 Trans Am 305 non H.O. The car will ...

Sent to Car Experts January 15 08:20 PM

I have a 1990 Trans Am 305 non H.O. The car will only start and run after fresh plugs are installed. So far I have replaced the converter and complete exhaust system, coolant temp sensor, fuelpump/sock filter, and computer when it does run it is very sluggish wont rev past 4000 rpm and the converter gets cherry red im guessing again that it is the fuel regulator or the injectors. after i shut the car off i go to the shrader valve on the fuel rail and there is no pressure at all Help Please

 

Optional Information:
1990 Pontiac Trans am 305 non HO

Already Tried:
converter, coolant temp sensor, fuelpump/filter, plugs,wires,cap,rotor new distributor and remaned ECM. i use to get the coolant temp sensor code only but not since i replaced it

Customer (name blocked for privacy)
Status:  Closed   Value: $15
Answer
January 15 8:40 PM (19 minutes and 40 seconds later)
         
ACCEPTEDCheck Mark

Hello.

Sound like you have a shorted injector.

Unplug all injectors, and test the resistance of each with an ohm meter.

Throttle Body Injection. Resistance should be 1.2 ohms+/- .1ohms

Direct port Injection/ Resistance should be 12 Ohms +/-

Please let me know if you have further questions. If you run into problems, please let me know.



Edited by rmldaytona on January 15 2007 at 8:40 PM
rmldaytona -- ASE technician -- 99% Positive Feedback on 508 Car Accepts
ASE Certified. Aerospace engineering studies. Drivebility.
Reply
January 15 9:11 PM (31 minutes and 37 seconds later)
         
would 1 injector cause so much flooding and no pressure at the shrader valve also there has to be a quart of fuel in the oil when i checked the dipstick
Customer (name blocked for privacy)
Reply
January 15 9:28 PM (17 minutes and 10 seconds later)
         
Ihave chacked the ohms resistance and i am showing 16 on all 8 injectors
Customer (name blocked for privacy)
Info Request
January 16 10:48 AM (13 hours and 19 minutes and 52 seconds later)
         
REPLIED to Info RequestCheck Mark

Don't replace anything yet. Let me look over some more data.

rmldaytona -- ASE technician -- 99% Positive Feedback on 508 Car Accepts
ASE Certified. Aerospace engineering studies. Drivebility.
Reply
January 16 5:07 PM (6 hours and 18 minutes and 21 seconds later)
         
Reply to rmldaytona's Post: Thanxs for the help my freind says it is probably the fuel pressure regulator but that dont make sense to me i also did a scan test on the ecm and all sensors are within range please help
Customer (name blocked for privacy)
Answer
January 16 6:24 PM (1 hour and 17 minutes and 30 seconds later)
         
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rmldaytona -- ASE technician -- 99% Positive Feedback on 508 Car Accepts
ASE Certified. Aerospace engineering studies. Drivebility.
Reply
January 16 8:07 PM (1 hour and 42 minutes and 58 seconds later)
         
Yes spark is excellent, plugs are acdelco r45ts, havent checked fuel pressure with a gauge when car is running but it has a brand new GM fuel pump and sock filter and fuel filter and a new distributor I did check pressure when running on ly by pushing on shrader valve and received a nice spray I was reading the manual and I know the mapsensor,Intake control temp sensor, and coolant temp sensor work together Ihave replaced all but itc sensor
Customer (name blocked for privacy)
Info Request
January 16 9:08 PM (1 hour and 43 seconds later)
         

Fuel pressure sounds to be the problem there. After the car stops running, there is suppose to be pressure in the rail. Do you still have a way to check fuel pressure? Could you please do that just to humor me. Also, notie how long it takes to drop after the car is not running.

Also...

Check the throttle position sensor for the following voltage.

Reference (Volts-DC) 4.8 - 5.2

Ground Level (Volts-DC) 0 - 0.05

Closed Throttle (Volts-DC) 0.36 - 0.96

Wide Open Throttle (Volts-DC) 4.5 - 5.2

 

GM is lurky on specifications on these injectors. GM says to be around 12 ohms +/- 1ohm. However, at the same time, they say to NOT follow ohm specifications for replacement. So, I suspect your injectors are sticking open, but I would like to investigate a few other possibilities. I'm sorry about all these questions. However, I would rather test every comonent on the car rather than replace one that will not fix your problem. So, please be patient wih me. Let me know what you find.

rmldaytona -- ASE technician -- 99% Positive Feedback on 508 Car Accepts
ASE Certified. Aerospace engineering studies. Drivebility.
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