Couple problems

[napatiger]

My 3.4 does not have the problem of delayed start when warm.
But one thing I notice is on my O2 sensor gauge, when it is cold, it sends a different voltage from when it is warm (about 5-10 min); so maybe your 02 sensor is sending mixed message when warm? Actually, I don't know how that would screw with starting, so I am just brain storming.

How do you start the car? For example, if you put the key to acc you can hear the fuel pump start and pressurize (I guess). Maybe when cold and warm, let the fuel pump do its thing before actually cranking. Just ideas.

[grandprixgtp_91]

all 3 of my 3.4L dohcs do that, and every newer 60 degreev6 at the dealership does it , we get alot of customers comming in and complaining, your might not do it because of the year, maybe 95 has a better program or something. we have a new pcm flash for the new vehicles that fixes it, but i dont know what causes it in the older ones .

Jake

[napatiger]

hmmmm, that is interesting. I mean most of the time it will start in like 1 second, once in a while it needs and extra 'rotation'. not too noticable though. maybe only when warm.
I did just get a kick ass rebuild with pretty good compression and basically blueprinted.
Interesting that there is a pcm flash that fixes it.
Damn, grandprixgtp you have a lot of DOHCs, that is cool. Do they all have the Getrag or some autos?
I think the worst thing that happened with my car that could not be 'fixed' was the tranny studder thing at cruzing. but a new tranny fixed that and now I just use royal purple, or Moble1 synthetic if I am broke. Tranny shifts faster and more firm.

How often do you suggest the cleener for the top end? I have about 10k miles on the rebuild.

[bud36light]

Dude if your sending injectors out, witchunter is on vacation till like the 12th. If you go the top engine cleener route, be prepared for the smoke show.

[grandprixgtp_91]

yeah all mine are getrag 284's, i have auto trannys but none of the cars have them in them, none of my cars that i have has an auto in it, ive just had it with autos, ive got a 93 grand am with a 3300 and i swapped that to a 5 speed, lol that was fun, then re tuning the compter my self , also a fun job. anyways about the gm top end cleaner , gm recomends to do it every 20,000km's , so 12,500miles, and i just do mine once a year regardless of mileage. and yes if you do the top end cleaner from gm it is gonna smoke a shitload, but thats all the carbon in your engine being burnt out, and i know that it is the carbon because when i ported my heads and intake, i did it all at once and while the heads were off , i dumped cleens all over the pistons and the domes of the heads and by the next day the carbon was mush and the pistions looked brand new , same as the heads, so then i put the motor back together and ran it for a day and then i dumped a bottle in the intake like i was doing a top end clean on it , and it didnt blow any smoke, so that actually is carbon being burnt out , that stuff works wonders. btw, with the tranny shuttering at cruising , did u change your torque converter? or the tcc silenoid? thats usually the cause or engine problems, so if you did the engine and tranny at the same time you might not have known which one it is.

Jake

[Carlspike]

I'll see about getting some top end cleaner tomorrow. I'll try and get the spray but if I can only get the liquid form how do you recommend I put it in the engine? Is carbon building a common problem on these cars? I drove the car with a scanner on it today and all the sensors seemed fine so I dunno what else it could be besides carbon.

[grandprixgtp_91]

carbon buildup is a problem in every car, and it gets alot worse with cars with egr valves , if you can only get the liquid then try getting a funnel with a hose on it and use that, but the spray will probably be better, when you dump the liquid in though dont just dump it all in at once, just dump it in fast engough so that when you get to the bottom of the bottle the car stalls, you should have to give it gas to keep it running and then at the end drop the throttle and let it stall, if i doesnt stall then shit the car off really quick, the reason you dont want dump it all in at once is so you dont hydro lock the engine.

Jake

[Carlspike]

If I can only get the liquid maybe I'll use a spray bottle or something for the first half. Sounds like that stuff will clean it pretty good. It must be dirty in there because the other day I washed it and noticed there was some carbon looking stuff on the rear bumper. I took it for a test drive right after I washed it and got on the throttle to see if I could help clean the engine out. When I got done driving it there was the same black crap all over the bumper already.

[grandprixgtp_91]

does this thing eat oil? u shouldnt get black stuff on your bumper unless there was water in the muffler and it blew out from the pressure, but i have seen bumpers turn black from oil consumption, usually blown rings, anyways just keep an eye out. try the cleaner, the dealer should have the spray , we stock tons of it, and when u spray, make sure you get all around the throttle plate to get it all over the intake to clean it, and spray it in the little hole in the side of the throttle body, thats your iac and she will idle must better if you spray some of that in there while its running, just make sure the car is at operating temp before you start doing any of this and when you let the stuff sit in the engine, only let it sit for 30 min so its still hot in the combustion chamber, and it might me a bitch to start, u might have to hold the gas to the floor and crank it for a min, and then give it alot of gas to keep it running, then its gonna blow a shit load of smoke, take it for a good hard run around the block and she should be running way better after that

Jake

[Carlspike]

Is it going to be a problem letting it sit for 30 mins at 10 degrees? I'll be doing this outside and it's pretty cold here. The dealer only had the liquid form, maybe I can order some from the net. Do you happen to have the PN? I don't believe it eats any oil. the black stuff was on the bumper in little speckles. It did look like the black watery stuff that I've seen come out of a muffler before. I haven't seen it do it again since that day about a week and a half ago. Twice when I started the car warm today it didn't stumble like before, it started right up. Maybe the carbon is already starting to get loose, I just want something to really get it cleaned out.

[grandprixgtp_91]

yeah its fine to do it at that temp. im just saying to make sure the motor is hot when you do it, and just dont leave it any longer than 30 min. i do it all the time here in canada at colder temps with no problem. anyways i can get you that part number for the spray tommorow when i got to work, but it might be a canadian number so i dont know if the dealer will be able to use it.
anyways try out the liquid and see how that works and let us know.

Jake

[Juglenaut]

If you use that cleens, clean the EGR ports and the EGR, you may have a sticky or siezed EGR.

[grandprixgtp_91]

if that was the case he would mosre than likely have an ses light , but it is a good idea to clean it too, just make sure you dont crack it putting it back on, the aluminum base cracks very easy if the bolts arnt tightened evenly .

Jake

[Carlspike]

Well the long crank seemed to be doing better until today. Last Friday I took it for 2 45 minute drives. I assumed this helped clean the engine out because the problem seemed to go away. Then yesterday it started doing the exact same thing again. It had been much colder than usual and I had numerous short trips so I just figured there was still some carbon to be loosened up. Anyway today I started it and got an SES light. It is code 42 Ignition Control Circuit. Then the next time I tried to start it I had to give it gas to get it to start. It then idled very low and stalled. I restarted it, having to give it gas again and feathered the throttle until it idled normally. There was no code after that start. So now I'm pretty confused. I know the ignition module was replaced before I owned the car. It had a bad crank sensor but the previous owner replaced the ignition module before he knew it was the crank sensor that was bad. I definently still want to run that cleaner through it but now I'm wondering about that code. Any ideas?

[grandprixgtp_91]

ive seen that code come on before, for 2 days, then stop and never come back, it is for more than just the icm, its for a few thing, and it could throw a code for a loose wire or anything.

Jake