AC on, all throttle 4000RPM issues cease.

[Blurrface]

Of course I've done a lot of searching on this subject and I know there are a lot of threads about it but I've never seen this particularly talked about.

I'm having the issue where I'm seeing some power loss at 4000+ RPM's. The strange thing, and what I've just discovered recently, is that if I have my AC on, these power issues go away. Just to update any reader, I'm getting the general sputtering issue at 4000+ rpms, nothing to hardcore, I'm not bucking, just sputtering a bit.

My question is, what exactly would cause the issue to go away if the AC is on? I've heard that it could be something related to the engine load and also that the electrical system could be behind it.

I'm looking for a technical answer to this question. I know I can fix the issue but why would the AC have anything to do with it?

No one has been able to answer that question yet.

[DCIV]

I really dont know if this is advance tech but I will leave it as you want a tech answer. It prob will not come quick though. So if you want it moved just say so.


Coop

[venik]

your AC could be draining power, and as a result your spark isn't as strong
if your getting sputtering it is either because the AFR is way off, or because your spark is bad. These people with the lean misfires are in denial that it is a spark problem. But if you read through the thread you'll find people saying replacing ignition related parts fixed their problems.

[Blurrface]

Yeah, it's not as advanced as another question that I could ask but I figure I'd get the most solid answer here. My presumption is that it's a spark issue, and I totally agree that most people with lean misfires have general spark issues.

Well, I could understand if I'm getting spark issues due to having the AC on (taking too much power), but I don't get how the assumed spark issue would go away with the AC on.

I mean, the AC and the spark wiring are on different harnesses unless I'm wrong.

My question isn't directed to solve the problem, just find out why it would stop sputtering with the A/C on. Where is the connection?

[venik]

oh i thought you said the opposite, ya that is interesting...

[Blurrface]

Yeah, it's been a few days now and I still can't figure out why this might be the case. I've been posting this question in a lot of places on other forums and no one seems have any clue as to why this would happen.

[markoverclock]

is the car stock? with stock ecu?

[markoverclock]

with the ac on the computer adds more fuel for the extra load. that could be why your sputtering check your 02's and the trims on a datalogger. your probally to lean without ac on.

[UPP]

^ I was going to say the same thing, but with ign. Is this on the 91 or the 94? If 91 check you're timing, (hell on the 94 too, just not sure how to easily adjust it on the 94 with stock everything).

I know the ecu kicks the throttle up, and if I'm not mistaken the fuel and timing too... Not 100%, but may be worth checking.

I also agree with everyone else about it being an ign problem. Fuel you have ALOT of play room. I can cruise anywhere between 10:1-16.5:1 before I really notice any difference, so for fuel economy I'm around 16:1.


UPP

[mxmikie]

change the biss screw o-ring and test your iac motor the ac overrides the idle in the iac