optispark or fuel issues?

[kmcminn]

Jeep still running rough on cold start it has a miss snap pop backfire when you hit gas. Snap on scanner shows no codes. Would it show if the optispark is bad. Possibly a fuel pressure issue. Maybe soft lines collapsing killing the fuel going to it. Fuel pressure gauge showed it dropping to around 30 when hitting the gas. Also opened the fuel cell it started running good. Noticed the fuel filter is soft to the touch and filling about 1/3 of the way up.

 

[LightBnDr]

Re: Air Temperature Sensor Parameters

Ok I take a go at it.

The link didn't work for me but I'll base it on my own experience.

How do you know the air temp sensor is bad? Is it broken or you guessing?

Second it's only an air temp sensor so if you're just testing a new style of sensor you can lay it on top of your air filter and run it through a heat cycle to confirm it works. Zip tie it worst case scenario and run it hard down the road. You want it as close to your filter as possible because that's where it's most accurate from cold start to closed loop.

Hope this helps

 

[zukimaster]

Re: Air Temperature Sensor Parameters

You can test most sensors with a ohm meter, just look up what the factory specs are, and if possible, use factory GM parts, seen to many part store sensors give lots of problems.

 

[lowbudgetjunk]

Re: Air Temperature Sensor Parameters

I'm just glad this ninja is figuring out what sensor is all ****ed up. I can only help with so many electrical problems

 

[pholmann]

Re: Air Temperature Sensor Parameters

If you haven't found what your looking for hope this helps.

This is the range for an lt1

This is the range for a truck 5.3

 

[kmcminn]

Re: Air Temperature Sensor Parameters

Thanks Pholmann.

 

[pholmann]

Re: Air Temperature Sensor Parameters

Now u owe me a cold beer

 

[kmcminn]

Re: Air Temperature Sensor Parameters

Now u owe me a cold beer

Now you owe me 5 instead of 6.

 

[pholmann]

Re: Air Temperature Sensor Parameters

 

[pholmann]

Re: Air Temperature Sensor Parameters

Why do you think that sensor is the culprit? What exactly is it doing? Do you have a diagnostic port? I know you said it's shot. Does that mean it physically broke?

 

[kmcminn]

Re: Air Temperature Sensor Parameters

One of the two wires that goes to the resistor is broken.

 

[pholmann]

Re: Air Temperature Sensor Parameters

Cool, replace your sensor and see if that's your only issue but an AIT won't generally effect that much. It definitely plays a part in the fuel air metering, but not near as much as a map, coolant temp, or mass air flow sensors. If it's just a little rough running then it may smooth it out. If it doesn't fix it holler at Me.

 

[kmcminn]

Re: Air Temperature Sensor Parameters

Ok I will the maf is about a month old. im going change it and unhook the battery try to clear it out.

 

[lowbudgetjunk]

Re:

Another broken wire.... Imagine that.

Kel Lawrence

 

[kmcminn]

Re: Air Temperature Sensor Parameters

Well fixed that issue. Running horrible still. Idles great gas it spits and pops. Put a high dollar snap on scanner today. No codes. I'm wondering if it is the optispark or maybe fuel?

 

[pholmann]

Re: Air Temperature Sensor Parameters

Clean your MAF

 

[muddinmetal]

Any drop in fuel pressure under load is bad, really bad.... I'd check voltage to the pump and if you are getting at least 12 key on, I would replace the pump asap before you blow a head gasket

 

[pholmann]

Any drop in fuel pressure under load is bad, really bad.... I'd check voltage to the pump and if you are getting at least 12 key on, I would replace the pump asap before you blow a head gasket

I was wondering if maybe where it was on its lid, could it have put trash from the tank in the filter or pump. I'd definitely check fuel pressure. Its hard to say what a hard hit like that could have dislodged or caused to go bad.

 

[kmcminn]

The air temp sensor smoothed up the idle but didn't fix the big issue. When I get home this weekend I'm going to check voltage at pump make sure it is getting good ground.

I would think that if it were the optispark it would be throwing a misfire or something.

 

[RebelRider]

Re: optispark or fuel issues?

I wouldn't rule out the opti just because it's not throwing a misfire. I had the same symptoms on my 95'. In case I missed it, what brand opti do you have?