Hard Start 92 2.8 Tbi

4pt9fiero · 10-26-2009, 08:00 PM

I have a 92 2.8 TBI, 5 Speed that has developed a hard start issue. I replaced the fuel filter thinking I may have a fuel flow issue - I couldn't remember the last time I replaced it so I figured it was time. I have to crank and crank and crank to get it to start. Sometimes if I hold the accelerator down it will try to start but won't. Sometimes after I get it to start if I blip the accelerator it will stall out. Sometimes when I start it it will run fine except that the SES light comes on. I need to disconnect the battery and clear the codes. I have experienced some extremely rich exhaust.

I have the following codes:
15 - Coolant Sensor Circuit Low/Open

34 - Map Sensor Signal Out of Range - Low

45 - Oxygen Sensor Rich Exhaust

If I can get it to run long enough to warm up and unplug the coolant sensor the idle will increase to that of a cold start.

I am not sure how to test the O2 sensor so I am not sure if it is good or bad but I am thinking that probably is not the problem.

Now the Map sensor, when I get it running and unplug the MAP sometimes it makes the engine speed up, sometimes it doesn't seem to make a difference.

Does anyone have any suggestions? I am thinking that i will buy a new MAP and give that a try. If there were problems with a sticking IAC would that cause these types of symptoms?

Has anyone else had these symptoms?

Thanks for looking,
Jeff

4pt9fiero · 10-29-2009, 11:31 PM

Update:

I pulled the IAC, cleaned and reinstalled - no difference.

I noticed that I have an injector that is not spraying the way it should, it appears like it is just dripping. I used a noid light and it appears that the injector is receiving the appropriate pulses. In order to further troubleshoot this issue, I swapped injectors and it made no difference.

Will low fuel pressure cause one injector to spray properly and the other to "dribble"?

Next step is to drop the tank and check the sock to see if it is restricting flow. Hard to say what I will find in the tank - hopefully it is not rusted and needing replacement.

4pt9fiero · 11-01-2009, 09:32 AM

Problem solved. I had a helper look to see if any fuel was spraying from the injectors when cranking, it was. Went to Autozone and bought a new coil. Turns out I didn't need it, the coil wire post on the coil was badly corroded; used a little sand paper to clean it up and now it is running well again - it even got rid of the slight miss I had.

So happy I didn't need to drop the tank.

10-26-2009, 08:00 PM	#1
4pt9fiero Registered User Age: 49 Join Date: Nov 2005 Posts: 23 Location: SE, Connecticut User is: OffLine	Hard Start 92 2.8 Tbi I have a 92 2.8 TBI, 5 Speed that has developed a hard start issue. I replaced the fuel filter thinking I may have a fuel flow issue - I couldn't remember the last time I replaced it so I figured it was time. I have to crank and crank and crank to get it to start. Sometimes if I hold the accelerator down it will try to start but won't. Sometimes after I get it to start if I blip the accelerator it will stall out. Sometimes when I start it it will run fine except that the SES light comes on. I need to disconnect the battery and clear the codes. I have experienced some extremely rich exhaust. I have the following codes: 15 - Coolant Sensor Circuit Low/Open 34 - Map Sensor Signal Out of Range - Low 45 - Oxygen Sensor Rich Exhaust If I can get it to run long enough to warm up and unplug the coolant sensor the idle will increase to that of a cold start. I am not sure how to test the O2 sensor so I am not sure if it is good or bad but I am thinking that probably is not the problem. Now the Map sensor, when I get it running and unplug the MAP sometimes it makes the engine speed up, sometimes it doesn't seem to make a difference. Does anyone have any suggestions? I am thinking that i will buy a new MAP and give that a try. If there were problems with a sticking IAC would that cause these types of symptoms? Has anyone else had these symptoms? Thanks for looking, Jeff
	[Reply w/Quote]

10-29-2009, 11:31 PM	#2
4pt9fiero Registered User Age: 49 Join Date: Nov 2005 Posts: 23 Location: SE, Connecticut User is: OffLine	Re: Hard Start 92 2.8 Tbi Update: I pulled the IAC, cleaned and reinstalled - no difference. I noticed that I have an injector that is not spraying the way it should, it appears like it is just dripping. I used a noid light and it appears that the injector is receiving the appropriate pulses. In order to further troubleshoot this issue, I swapped injectors and it made no difference. Will low fuel pressure cause one injector to spray properly and the other to "dribble"? Next step is to drop the tank and check the sock to see if it is restricting flow. Hard to say what I will find in the tank - hopefully it is not rusted and needing replacement.
	[Reply w/Quote]

11-01-2009, 09:32 AM	#3
4pt9fiero Registered User Age: 49 Join Date: Nov 2005 Posts: 23 Location: SE, Connecticut User is: OffLine	Re: Hard Start 92 2.8 Tbi Problem solved. I had a helper look to see if any fuel was spraying from the injectors when cranking, it was. Went to Autozone and bought a new coil. Turns out I didn't need it, the coil wire post on the coil was badly corroded; used a little sand paper to clean it up and now it is running well again - it even got rid of the slight miss I had. So happy I didn't need to drop the tank.
	[Reply w/Quote]