90 BII Engine trouble

[uscg10]

I have a 90 BII with a 2.9. I have changed plugs,wires,dist.cap, and have also cleaned the intake and idle air control. It has some power on cool mornings but on hot days no power, surges, and back fires out of the intake. Any help would be great. thanks

 

[Earl43P]

The usual suspects, Coolant temp sensor, Intake air temp sensor, MAP sensor.

If you use an ohmmeter and heat / cool those sensors and the ohms change, I'd guess they are good. The Haynes manual doesn't give any values for them.

http://www.therangerstation.com/tec...es/Diagrams_ElectronciEngControls2_9_2of3.JPG

The coolant temp sensor has two wires, the gage sender has one.

 

[adsm08]

Shot O2 sensor is always a good suspect for no power and back fires.

 

[4.0B2]

No codes?

 

[adsm08]

My O2 sensor fell apart and didn't set a code. The early systems are pretty crappy.

 

[4.0B2]

Yeah I know but just thought I'd refresh his memory incase there is one, or I've had tikes to where my engine light never came on yet I had fresh codes. So it never hurts to check.

 

[Shran]

Backfiring out of the intake indicates a timing issue to me.

 

[adsm08]

Aren't timing-related backfires usually worse when the engine is cold though?

 

[4.0B2]

Aren't timing-related backfires usually worse when the engine is cold though?

i thought so to... but heck, you never know with the demons inside the motors sometimes...

 

[Shran]

Aren't timing-related backfires usually worse when the engine is cold though?

I guess it just depends on how much the timing is off and if it advances or not. Either way it's not firing when it should.

 

[4.0B2]

Yeah.. So check timing. That makes sense. Lol. I'm not used to that anymore since the swap... Lol.

Also any sensor. Mainly o2, coolant temp, or tps... Hmm idk..

 

[Tedybear]

Aren't timing-related backfires usually worse when the engine is cold though?

Depends on if the TFI module is good or bad. When they fail? Normally they are good until they get up to temp--and then it can't regulate the timing as well as it should.

 

[uscg10]

Haven't checked the codes. Thought it may be a timing issue. Will also check out the TFI module. Also am going to check the intake for any leaks. Will post my results and thanks for the input. Anymore ideas appreciated.

 

[uscg10]

well took my truck to the shop and like always they couldn't tell me anything. Said the timing was good but couldn't get any codes off of it. Any help. Need to get this thing running.

 

[4.0B2]

idk without seeing it in person really... if you were closer i'd help ya out some.