2000 gtp messed up

[bryans restoration]

this is my first reply under this name but i have posted on here before and got help.. ok...this is very stressfull my gtp runs fine when it is cold but as soon as it gets to operating temp it misses or, the SC kicks out, or gas is cutting off. i dont know but its killin me when i cant accelerate past a civic on the E-way. as soon as you give it about quarter throtle when it should kick down from 3rd to 2nd or 4th to 3rd it sputters, occasionally hear a backfire under the hood possibly??, and even just str8 up breaks down sometimes!!!!!! i am no mechanic but no fool. i ran the computer through it and the o2 sensor said it was bad so i changed it. i shouldve known this wasnt going to fix it, it is more than that. i bought it with 67k, put a 3.4 pulley on it, autolite 605's, CAI, msd 8.8 wires...just simple stuff. it ran like a raped ape for the longest time now it is only running good when cold. this makes me think that the sc is fine but like i said im not 100% sure... it has 114k on it now and it looks like new. im not giving up yet. please help. another code was MIL, which i think is the SES light burned out, and sometimes EVAP emmision control system comes up. you guys think it is the ignition control module? coil packs? any pointers would be great like i said if there is a function i can check on the pc let me know cause some of those numbers just didnt look right.. thanks again ryan

[BNaylor]

Originally Posted by bryans restoration

this is my first reply under this name but i have posted on here before and got help.. ok...this is very stressfull my gtp runs fine when it is cold but as soon as it gets to operating temp it misses or, the SC kicks out, or gas is cutting off. i dont know but its killin me when i cant accelerate past a civic on the E-way. as soon as you give it about quarter throtle when it should kick down from 3rd to 2nd or 4th to 3rd it sputters, occasionally hear a backfire under the hood possibly??, and even just str8 up breaks down sometimes!!!!!! i am no mechanic but no fool. i ran the computer through it and the o2 sensor said it was bad so i changed it. i shouldve known this wasnt going to fix it, it is more than that. i bought it with 67k, put a 3.4 pulley on it, autolite 605's, CAI, msd 8.8 wires...just simple stuff. it ran like a raped ape for the longest time now it is only running good when cold. this makes me think that the sc is fine but like i said im not 100% sure... it has 114k on it now and it looks like new. im not giving up yet. please help. another code was MIL, which i think is the SES light burned out, and sometimes EVAP emmision control system comes up. you guys think it is the ignition control module? coil packs? any pointers would be great like i said if there is a function i can check on the pc let me know cause some of those numbers just didnt look right.. thanks again ryan

For starters since you have a CAI try removing and cleaning the MAF sensor with MAF sensor cleaner. It's located on the top of the throttle body and held on by two Torx safety screws.

Also if you have the SES light on get it scanned for odb-ii DTC error codes.

[bryans restoration]

Originally Posted by bnaylor3400

For starters since you have a CAI try removing and cleaning the MAF sensor with MAF sensor cleaner. It's located on the top of the throttle body and held on by two Torx safety screws.

Also if you have the SES light on get it scanned for odb-ii DTC error codes.

thanks for the advice man i will do that and check back with you... ryan

[bryans restoration]

[quote=bnaylor3400]For starters since you have a CAI try removing and cleaning the MAF sensor with MAF sensor cleaner. It's located on the top of the throttle body and held on by two Torx safety screws.

Also if you have the SES light on get it scanned for odb-ii DTC error codes.


i took of the maf sensor and it looks clean as a whistle and all the wires inside are connected. but i know looks are not everything, i blew it out with a low pressure air hose and everything is the same, i couldnt get maf sensor cleaner at the time but is their something in it that cleans differently? idk. a respectable mechanic i know told me that its more than likely my ignition module and they go for 200 somethin bucks. what do you think??? this guy is a import mechanic so idk. any more advice would be great! thanks man.

[BNaylor]

Gunk makes MAF sensor cleaner but any spray electrical contact cleaner will work. Clean only the hot wire elements exposed to airflow.

Before replacing the ICM or messing with the coil packs get it scanned for any obd-ii misfires codes if SES light is on otherwise it just a guessing game. On most misfire problems it is very seldom the ICM so replacing it may not fix your problem. How old are your Autolite 605 spark plugs and MSD wires. Is your CAT convertor the orginal or an aftermarket?

[bryans restoration]

I scanned it about five mins ago and whoala there are no codes whatsoever.
couple weeks ago the 02 sensor code was on and now its gone. i used to have AL 104s but i switched to the AL605 'cause someone told me they were a little cold for my setup. the wires are about 11 mos old and i had the 605's put in not even 2 mos ago and i even took one out and they look excellent. is there any way (safe way) to test the ICM cause i got zapped pretty damn good while pulling one wire off at a time on the coil packs. but i noticed the bottom wire ( i think it was #1 or #2 cyl) had like a stall in the arc compared to the others. this probably isnt the safest way to test obviously but do you think a single coil pack would cause that?: or the whole ICM. cause i called on one of those and their goin for 350 bucks and that would suck but it would be worth it. this guessing game is tricky but im not givin up till this thing is back on its game. like i said its only when it gets warmed up its f'd up. when its cold its awesome. so that makes me think that the coil packs are fine. sorry to keep bothering you, but i dont want no junk ass mechanic scammin me over somethin stupid. thanks a whole lot again man. ryan....

[BNaylor]

Originally Posted by bryans restoration

I scanned it about five mins ago and whoala there are no codes whatsoever.
couple weeks ago the 02 sensor code was on and now its gone. i used to have AL 104s but i switched to the AL605 'cause someone told me they were a little cold for my setup. the wires are about 11 mos old and i had the 605's put in not even 2 mos ago and i even took one out and they look excellent. is there any way (safe way) to test the ICM cause i got zapped pretty damn good while pulling one wire off at a time on the coil packs. but i noticed the bottom wire ( i think it was #1 or #2 cyl) had like a stall in the arc compared to the others. this probably isnt the safest way to test obviously but do you think a single coil pack would cause that?: or the whole ICM. cause i called on one of those and their goin for 350 bucks and that would suck but it would be worth it. this guessing game is tricky but im not givin up till this thing is back on its game. like i said its only when it gets warmed up its f'd up. when its cold its awesome. so that makes me think that the coil packs are fine. sorry to keep bothering you, but i dont want no junk ass mechanic scammin me over somethin stupid. thanks a whole lot again man. ryan....

On the ICM best thing to do if you have an Autozone nearby is to have them check it out for you. They will do it for free and can do any GM ICM for a Series II 3800 SC or NA. On the coil packs you can swap them around but if one is defective you will just be moving the problem around and it may not prove anything.

AZ has the ICM for around $130.00

On the Autolite copper core spark plugs 605 are one range colder, 104 two and 103 three than the stock.

[bryans restoration]

thanks for all the advice bnaylor but ive got bigger probs now. right after i sent that last message i jumped in my car to go home and the mofo wouldnt start!! i am now getting no spark whatsoever. we have a 1999 monte Z34 with the 3.8 on the lot for sale. so i took the ICM off of that car and swapped it with mine. both units are indentical. i plugged it in my ride and still no spark! i plugged mine in the monte and it runs great from top to bottom cold or hot. the swap took about 15 mins. i am stumped so i called the wrecker and had it towed down to caddy corner (a business partner) they work on GM cars only and i told my mechanic that i dont want it back till its running perfect. so i will be paying out my ass probably. i think it is either the computer or the crank sensor?? if it is the computer who sells the best reprogrammed unit? and do you think that i should be running those 605's or the 104's. when it gets back i have a fabbed exhaust peice with a nut welded to it for the u-bend delete. im still not sure. thanks again.. ryan

[BNaylor]

Originally Posted by bryans restoration

thanks for all the advice bnaylor but ive got bigger probs now. right after i sent that last message i jumped in my car to go home and the mofo wouldnt start!! i am now getting no spark whatsoever. we have a 1999 monte Z34 with the 3.8 on the lot for sale. so i took the ICM off of that car and swapped it with mine. both units are indentical. i plugged it in my ride and still no spark! i plugged mine in the monte and it runs great from top to bottom cold or hot. the swap took about 15 mins. i am stumped so i called the wrecker and had it towed down to caddy corner (a business partner) they work on GM cars only and i told my mechanic that i dont want it back till its running perfect. so i will be paying out my ass probably. i think it is either the computer or the crank sensor?? if it is the computer who sells the best reprogrammed unit? and do you think that i should be running those 605's or the 104's. when it gets back i have a fabbed exhaust peice with a nut welded to it for the u-bend delete. im still not sure. thanks again.. ryan

Definitely not good news. On the CKPS or PCM, it's 50/50 but I'd put my odds on the crank sensor since there is no spark and starting is difficult. Maybe it is the root of all your problems.

If it turns out to be the PCM, check with Ed Morad on EBay or ClubGP. He has them for as low as $55. Just make sure it matches your year GTP.

Whether you run Autolite 605 or 104 is dependent on gas quality and any knock retard that may show. But either will work with a 3.4 SC pulley. Good luck!

[bryans restoration]

well thanks a whole lot man youd win in vegas because it definetely was the krank case sensor. and it was the root to all of my problems. i walked in the shop and my mechanic had a big tv screen with a heartbeat, a bunch of wires hooked up to my car, and a big white peice of paper with a big diaphram of all these electrical sensors and components and it was up and running fine. and when i pulled the gas it wound up quickly with no hesitation whatsoever and it was at operating temp. he said he was finishing up, checking some stuff just in case, and hed call me with the bill in an hour. man i cant wait to get that bill. thanks very much for all the help my problem is solved. this website and the people on it (most for that matter) are very knowledgeable and i think it is great!