This is what the car is doing: Take off from a stop and go WOT, it runs like a champ up until 2500 -3000 rpm then hesitates for about a second (but this is a good 1 - 1.5 seconds where nothing is firing), then is back like nothing happened. About 2 seconds after this the SES light will come on. It will do it in 1st, 2nd, 3rd as long as you are running up the rpm range quickly. I put it in 5th and 6th and floored it trying to get it to do it and it won't, I guess it has to be going up the rpm band quickly...

If I shut the car off the SES light will go off and it will act like nothing ever happend, until I go WOT again and it is deja vu.

Also, (and I am not crazy when I say this), but after it hesitates and throws the SES light, the A/C quits blowing cold. I am serious as a heart attack, I dunno what it is. But, once I shut the car off for I dunno 20-30 seconds, turn it back on, it blows Ice Cold...

I have replace this in the past 4 months (all Delco or high end products)

opti, plugs, wires (now otvc taylors), coil, csr h2o pump, fuel filter, 02's, !egr, !air, pacesetter lt's, pcv and most other tuneup essentials (I don't feel like thinking of the rest)

One thing I did not replace was the ICM... I am going to check the fuel pressure at the schrader valve and check for fireworks coming from the taylors and get back with you tomorrow night.

This is not the 4500+ rpm stumble many people have when opti's are going bad... This is different. There is a complete 1 - 1.5 seconds where there is NOTHING.

Please throw out some ideas!

Also, I have not deleted the !agr and !egr on a PCM tune yet, but the car has been running fine like that for 4 months...

 

Im having a very similar problem with my 97 ss, but i have a 6 speed. i changed the mass air flow sensor and my spark plugs and still have the problem. i'm changing 02's next. it happened a week after i reinstalled my longtubes, they went out for recoating. i get the ses light and then it goes off, and comes back. autozone tried to check it but only got a error cause its not storeed into the computer, said i need to run a complete scan test at a shop.

soulds like were having the same problem, once over 2k rpm i get a stumble and it doesnt fire until a second or 2. it i put it in neutral and rev it it hesitates a sec before reving up.

hope its my 02's cause i cut into my old ones to search for burnt wires. but found nothing.

let me know if you find anything out about the problem,.

 

I replace my 02's as well back in April...

Any thoughts / ideas?

 

next time the code comes take it to a shop and get the code scanned. that would be the best bet. and dont take it to advanced/autozone.
but since you havent done it yet, i urge you to get the fuel pressure gauge set up and see what your fuel pressure is.

 

check your fuel pressure regulator and see if the vacuum line is still connected to the manifold. Make sure its in good shape. No vacuum to the fuel pressure regulator means fuel starvation for the engine which could trip an alarm with the computer.

 

if anything my car smells rich. i've tried new plugs 02's and MAF, still no cure. im taking it to a shop tomorrow morning and having some tests run to find out where my problem is. $29.99 seems worth it. i just have to get it there. but ill check that hose on mine before i take it. i hate having my car sit with problems.

i hope SentimentalValue and i can get our cars fixed.

thanks for the info. ill come back to update when i get my results

so i decided to start taking things apart and came across something interesting. when i took off my pass valve cover, i found part of a wire look clip inside. it is the one thats mounter right in the midle of the valver cover and gets in the way when you try to take the cover off or put it on. somehow when i was putting it back on after the header install it snapped off and fell in. and the rest of the clip was causing a gap between the valve cover and the head, so i was looking a little pressure.

not it runs like a champ. but i dont know if it caused anything else i should worry about.

 

Bad news, pulled the code today with TECH 1 and it's DTC 36: High Res Pulse

The guys on a local board told me the code meant this:

DTC 36 Distributor Ignition System
(Faulty High Resolution Pulse or Extra Low Resolution Pulse Detected)

http://www.lt1edit.com/pipermail/lt1...19/014273.html

Looks like Opticrap.

Please tell me this code could mean something besides the opti. I put that stupid thing in in April... Could it be the ICM or anything along those lines? I don't mind replacing it, I just don't feel like throwing out the moolah right now. I guess I could try out one of those new MSD's or Accel units...

Also, checked the FP today and it was 43-44 WOT and 34ish at idle.

Checked the TPS and it was 0.4 Volts closed throttle and 4.4 Volts at WOT.

I unhooked the MAF sensor also today and drove it around. The bish still had the "miss".

 

I've never had the privilage messing with optis but check the plug going to the opti make sure it isn't damaged or corroded. My guess is if the computer get intermittent signals (I.E. loose wire) it might confuse the signal and throw a code while the engine hesitates.

The engine needs the MAF sensor to run properly in 94+ cars. Check the opti plug and unhook the battery for 10 minutes to reset everything. Then try it again. Otherwise you may have to dig deeper.