bogging/missing at low rpm.

[Titanium89sho]

I have been working on my '91 S/C SHO lately, had a few oil leaks to fix (the return line fitting on the oil pan mostly). I also changed the plugs to autolite 3923's, and new wires. The car has absolutely no leaks now.

The problem is that after hooking everything back up, the car bogs and surges at low rpm. Once it hits about 3000, it takes off like a bat outta ****. (no misses and pulls really hard all the way to 7000)

I never had a bogging issue before, so can anyone think of a reason for it to bog slightly at low rpm's?

Any help would be greatly appreciated.
Jessey

 

[AREA 91]

Are those the same plugs you used before?
What did you gap them at?

 

[Titanium89sho]

no, the car had the denso plugs that people were having separation issues with so I switched to the autolites. I was reading some posts on here, and gapped them to between .035-.040.

Edit: The car is idling normally. The bog/miss is under load at low rpm.

 

[yamahaSHO]

I'm not sure that the problem is the plugs (could be), but I would have taken the gap to .03 - .035. If the plugs were blowing out, you should notice it more at higher rpm with all the extra density in the cylinder (not accounting for the extra heat created).

 

[Titanium89sho]

ya, I already tried re-gapping to .032. I also filled up with fresh 94 octane, but there is still a slight mis or bog or surge, whatever you want to call it. I goes away at 3000 rpm or so. Any other ideas????? I am going to change the fuel filter and check the psi at the fuel rail. It should be 39 psi at idle right?

Edit: Unplugged the MAF and it idled perfect, no misses under load. I will try to clean the MAF and see if that fixes it. Hopefully I don't need to replace it.

Jessey

 

[89SHO X2]

Possibally the MAF sensor I had a problem with mine surging at idle and bogging when the secondaries kicked in. I dissconnected the MAF and ran great. Left it off for now. Maybe the connector is loose and maybe have a loose connector or wire is loose or messed up. also the plugs could be none compatible with the engine. Thought this may help. Take care.:wave: Also I got the Autolite double platinums and they work fine.