Idle jumps up and down

[shotime1994]

I have a 94 mtx with 105k. It has bbbs, 77mm throttle body, port and polished intake runners, 73mm maf, cai, with a chip. I did a 60k on her a couple of months ago and the car has been running great. I start it up in the morning drive it somewhere shut it off get back in it and the idel starts going for about 400rpm to like 1k then if I hit the gas it backfires. Any input on this? No codes and I replaced the maf already. Thanks


Andrew

 

[1995SHO9]

Sorry bro, I didn't hear back from brian...

 

[93rev2sev]

DIS or coilpack?

 

[1995SHO9]

DIS or coilpack?

I talked to him earlier, the only thing that threw me off was the backfiring, and the fact that he said it didn't do it all the time.

I know timing will do that, but it isn't doing it all of the time.

So rev2, your saying a bad coil pack or dis will cause backfiring as well?

 

[shotime1994]

New dis and new coil pack I already replaced them.

 

[1995SHO9]

Did you use di electric grease on the dis?

 

[shotime1994]

I believe I did im sure I did.

 

[shotime1994]

Now the oil light comes on when the idel drops to like 300rpm

 

[AREA 91]

I have a 94 mtx with 105k. It has bbbs, 77mm throttle body, port and polished intake runners, 73mm maf, cai, with a chip. I did a 60k on her a couple of months ago and the car has been running great. I start it up in the morning drive it somewhere shut it off get back in it and the idel starts going for about 400rpm to like 1k then if I hit the gas it backfires. Any input on this? No codes and I replaced the maf already. Thanks Andrew

Check your mechanical timing. Pull the upper timing cover. Check your cam sensor wiring, and see if there is oil inside of it.

I also see that you have a "chip". Pull that out first, and try to re start.

Now the oil light comes on when the idel drops to like 300rpm

This is normal, when the RPM's are that low.

 

[shobote]

Surging idle; might check all the couplers on the intake to make sure the clamps are tight and there are no cracks in any. Remove chip; put stock 55mm MAF in, the 73mm C & L is either hit or miss; it may sound louder, but that does not mean faster. Use reset idle procedure. It will also take a few WOT runs to relearn. Backfire is strange; are you sure this is not misfire, as backfire sounds like a gunshot... did you replace plug wires at 60k; any water/oil in the plug wells ?

 

[shotime1994]

I just did another 60k at 104k And I did valve cover gaskets and it is a backfire.

 

[Phoenix]

Check for vacuum leaks.