I finally found out what was causing my hesitation. After replacing my Opti, my O2's, spark plugs, and coil, I found out what was causing my problems. The IAT sensor was always sending a cool air code to the computer. In the morning when the air was nice and cool the car ran great. But when it would warm up outside, the car still thought it was getting cool air and wouldnt adjust the fuel air mixture. I also took off my TB and cleaned that all up. My IAC sensor was also really really dirty when I took that off the TB. I cleaned that up and now the car idles better than it did before. FINALLY I GOT IT!!!!!

 

Approx. where on the RPM band was the bad hesitation happening?

 

Also how did you solve it did it throw a code?? or what it a hit or miss?? just wondering b/c of how many of these cars have the hesitation problem

 

Just to ad a note.... I was doing some mods using the Coolant Temp sensor and I came across the same issue. I am sure someone here could have told me in advance not to mess with the sensor but I found out on my own.

I was just making the PCM think the car was 15*f degree warmer. and the car ran good but in the morning it would take a long time to start up. This Temp sensors do have a profound effect on the performance of our cars.. I reset it to OEM specks and now the car starts right up when cold.


Marvin

 

My hesitation was happening right where everyone elses is happening, up until 2000 RPM. It would also stumble going into second gear when it would lose its RPM's there. I used a scanner to see that it was not changing the temp input. I think this answers most of what you guys asked me.

 

WHen you had it scanned.. how far off from what the temperature really was was the sensor reading? Like "-30" or was it juts 20-30 degrees off?

 

I'm not really sure how far below the actual temp the the sensor was reading, the guy who scanned it didnt say how low, just that it was reading low. I guess I could ask him and post that later.

 

My IAT was telling the computer that the air was 40 degrees cooler than it actually was. Hope this helps you guys out!!!

 

Thanks Z28boss! Does anyone here know what the resistance : temp ratio the thermosistor is suppsoed be at (so that we can check it on our multimeters)

 

Whoa man, way over my head!!! HA HA

 

my hesitation went away with new plugs/wires

i think everyone gets a very similar hesitation problem..........but there are a variety of different causes for it.

 

I've posted many times about this surge/hesitation problem that for me occurs only when above 220*.

First I changed my o2s no help.
Today I changed my IAT, problem seems to be solved for now.
I also have a map & tps on stand by.

Plugs wires & fule filter done prior as normal maitenance, no help to problem though.

IAT was $10 form Sam Taylor, for the price I thuink everyone who has this problem should go for it.