2001 Tahoe-misfire code-hard start READ!

First post but I have to share the recent warranty work performed on my 2001 4.8L tahoe.
End of January 2004 my MIL (check engine light) came on for about an hour and then went out. I called the dealer as warranty is up mid April and was told it may just be the fuel cap as I had recently filled up. Let it go for a few days and see if it returns. For the rest of the week the light came on and off sporadically and then was on steady for two days. For the hell of it I bought a new fuel cap but that didn't work so brought it in to the dealer on Feb 5. Turns out it was code p0301, misfire #1 cylinder. They changed out the spark plug, plug wire and coil but still had a misfire code. (I'll mention here that at no time in the past three years had I felt anything but a smooth running engine). Gave me a loaner car and told me to call the next day. Dealer called the next afternoon and said they had finished peerforming a fuel rail and injector cleaning and the misfire code was still there. They would do a combustion chamber cleaning over the weekend and call me on Monday.
Monday afternoon they call and all is well he says so I pick up the Tahoe that evening. Next day at work (I use the vehicle on company property) the light comes back on by 10:30 that morning so I call them back and the Service Adviser wants me to keep it the rest of the week to run a tank of gas through and see how it goes. Ok , I'm game. I have to mention here that now the engine has a very obvious rough idle. So I drive and the MIL comes on and goes out here and there and by thursday it's on steady and at one point flashes for a few seconds indicating a misfire is happening at that moment. I bring it in friday, get the same little tin can Cavalier and go home to wait for news.
I'll tell you about the hard start part of the thread title now. Within the first 10000 km I was having hard starting problems. Occasionaly I would have to crank the engine 4 - 6 seconds before it would start. The hard start would happen wether the engine was warm or cold or even if it had been running five minutes before. Once this symptom began I made sure that the fuel pump had pressurized the system and stopped pumping before I attempted to start the engine. Two days of check out at the dealer and they could not find a problem so I've been living with it since hoping the starter fails due to excessive cranking before the warranty expires.
Back to the present. Tuesday morning they call and tell me GM Tech Service believes the lifters are faulty and they are tearing down the top end to replace them :dunno: . As I have never had so much as an errant tick or oil pressure problem with this engine I am confused and more than a little concerned but cheerfully offer to break in a new engine :biggrin:. By the following Wednesday I get concerned and call. The Service Adviser tells me they found nothing wrong with the lifters and a tech from GM Technical Services in the States (I'm in Southern Ontario, Canada) arrived the previous evening and is checking the Tahoe as we speak. He'll keep me informed. That evening he tells me they are going to send all the injectors out to be flow tested on Thursday, keep the car for a while longer. Well at least they've brought in the big guns. Friday afternoon I get THE CALL. It seems they found two injectors that were flowing TOO MUCH fuel and after replacement everything seems to be fine, come and get the Tahoe.
Sorry about the length of this but we're almost done. It's been eight days now and no MIL, the idle is rock solid smooth AND it has started right away EVERY time. So it seems the hard start was caused by injectors flowing too much fuel. Wouldn't an exhaust gas analysis have shown a rich fuel/air mixture to begin with? Anyway as I've read numerous threads with hard starting complaint I hope this tale can help someone. Thanks for listening.

gm has faulty fuel injectors and they know it. california has recalled all gm trucks suv's and vans 96'--2001 to clean or replace fuel injectors with new style injectors currently in 2002 and up models. only in CA. as for the rest of us were shit out of luck. your problem was the poppet's in the injectors were sticking open spraying fuel all the time. Not all dealerships know of this. There are so many bulletins out there they just don't have time to read them all. It is more expensive to replace all the injectors with the old stlye (scpi) (that are defective) than it is with the new style mfi. all you have to do is call any dealer and give them this service bulletin# 00-06-04-003B then they can review it and get prices for the conversion. the part #'s are
93441235-- v-8 mfi assembly
17113206-- v-8 deal kit
93442096-- v-8 bracket
toatal cost for parts should be around $340.00 plus labor


First post but I have to share the recent warranty work performed on my 2001 4.8L tahoe.
End of January 2004 my MIL (check engine light) came on for about an hour and then went out. I called the dealer as warranty is up mid April and was told it may just be the fuel cap as I had recently filled up. Let it go for a few days and see if it returns. For the rest of the week the light came on and off sporadically and then was on steady for two days. For the hell of it I bought a new fuel cap but that didn't work so brought it in to the dealer on Feb 5. Turns out it was code p0301, misfire #1 cylinder. They changed out the spark plug, plug wire and coil but still had a misfire code. (I'll mention here that at no time in the past three years had I felt anything but a smooth running engine). Gave me a loaner car and told me to call the next day. Dealer called the next afternoon and said they had finished peerforming a fuel rail and injector cleaning and the misfire code was still there. They would do a combustion chamber cleaning over the weekend and call me on Monday.
Monday afternoon they call and all is well he says so I pick up the Tahoe that evening. Next day at work (I use the vehicle on company property) the light comes back on by 10:30 that morning so I call them back and the Service Adviser wants me to keep it the rest of the week to run a tank of gas through and see how it goes. Ok , I'm game. I have to mention here that now the engine has a very obvious rough idle. So I drive and the MIL comes on and goes out here and there and by thursday it's on steady and at one point flashes for a few seconds indicating a misfire is happening at that moment. I bring it in friday, get the same little tin can Cavalier and go home to wait for news.
I'll tell you about the hard start part of the thread title now. Within the first 10000 km I was having hard starting problems. Occasionaly I would have to crank the engine 4 - 6 seconds before it would start. The hard start would happen wether the engine was warm or cold or even if it had been running five minutes before. Once this symptom began I made sure that the fuel pump had pressurized the system and stopped pumping before I attempted to start the engine. Two days of check out at the dealer and they could not find a problem so I've been living with it since hoping the starter fails due to excessive cranking before the warranty expires.
Back to the present. Tuesday morning they call and tell me GM Tech Service believes the lifters are faulty and they are tearing down the top end to replace them :dunno: . As I have never had so much as an errant tick or oil pressure problem with this engine I am confused and more than a little concerned but cheerfully offer to break in a new engine :biggrin:. By the following Wednesday I get concerned and call. The Service Adviser tells me they found nothing wrong with the lifters and a tech from GM Technical Services in the States (I'm in Southern Ontario, Canada) arrived the previous evening and is checking the Tahoe as we speak. He'll keep me informed. That evening he tells me they are going to send all the injectors out to be flow tested on Thursday, keep the car for a while longer. Well at least they've brought in the big guns. Friday afternoon I get THE CALL. It seems they found two injectors that were flowing TOO MUCH fuel and after replacement everything seems to be fine, come and get the Tahoe.
Sorry about the length of this but we're almost done. It's been eight days now and no MIL, the idle is rock solid smooth AND it has started right away EVERY time. So it seems the hard start was caused by injectors flowing too much fuel. Wouldn't an exhaust gas analysis have shown a rich fuel/air mixture to begin with? Anyway as I've read numerous threads with hard starting complaint I hope this tale can help someone. Thanks for listening.

I'm aware of the problem with older scfi injectors, thanks to this forum and others, but mine are in fact the newer MFI injectors. The injectors operation was ok but a bench flow test showed that in a supposedly flow matched set of 8 injectors 2 were off spec(flowrate was too high). My post was mainly aimed at newer Tahoe owners having a longer than normal crank before starting problem as a possible cause of the condition. Thanks for the reply.

I don't understand why they couldn't tell you this right away without sending the injectors out. With the new electronics these injectors are so easy to check in the vehicle. If a Technician uses a good fuel pressure gauge and the GM scan tool (Tech 2) and proper procedure the fuel injectors are easier to test than replacing the spark plugs. I think a good Technician could have found this right away, even with out a gas analysis. Better luck next time.

Exactly! Maybe we make the assumption that all dealers have the latest test instruments and the knowledgable, trained technicians to utilize them properly. Heck just from reading the online GM Techlink publications even I know that, as you said, using the built in test routine on the Tech II for pressure drop testing injectors and a Kpa scaled pressure gauge one can get a good idea of the flow rates. As I have not heard a word from them in the two weeks since I got the truck back I can only assume they are feeling a bit sheepish over the poor troubleshooting strategy shown in this case.

thanks for the info I just put in my 4th starter in 2 yrs, my 97 tahoe continues to start hard, smells a little rich and idles rough, what do you think I should do?First post but I have to share the recent warranty work performed on my 2001 4.8L tahoe.
End of January 2004 my MIL (check engine light) came on for about an hour and then went out. I called the dealer as warranty is up mid April and was told it may just be the fuel cap as I had recently filled up. Let it go for a few days and see if it returns. For the rest of the week the light came on and off sporadically and then was on steady for two days. For the hell of it I bought a new fuel cap but that didn't work so brought it in to the dealer on Feb 5. Turns out it was code p0301, misfire #1 cylinder. They changed out the spark plug, plug wire and coil but still had a misfire code. (I'll mention here that at no time in the past three years had I felt anything but a smooth running engine). Gave me a loaner car and told me to call the next day. Dealer called the next afternoon and said they had finished peerforming a fuel rail and injector cleaning and the misfire code was still there. They would do a combustion chamber cleaning over the weekend and call me on Monday.
Monday afternoon they call and all is well he says so I pick up the Tahoe that evening. Next day at work (I use the vehicle on company property) the light comes back on by 10:30 that morning so I call them back and the Service Adviser wants me to keep it the rest of the week to run a tank of gas through and see how it goes. Ok , I'm game. I have to mention here that now the engine has a very obvious rough idle. So I drive and the MIL comes on and goes out here and there and by thursday it's on steady and at one point flashes for a few seconds indicating a misfire is happening at that moment. I bring it in friday, get the same little tin can Cavalier and go home to wait for news.
I'll tell you about the hard start part of the thread title now. Within the first 10000 km I was having hard starting problems. Occasionaly I would have to crank the engine 4 - 6 seconds before it would start. The hard start would happen wether the engine was warm or cold or even if it had been running five minutes before. Once this symptom began I made sure that the fuel pump had pressurized the system and stopped pumping before I attempted to start the engine. Two days of check out at the dealer and they could not find a problem so I've been living with it since hoping the starter fails due to excessive cranking before the warranty expires.
Back to the present. Tuesday morning they call and tell me GM Tech Service believes the lifters are faulty and they are tearing down the top end to replace them :dunno: . As I have never had so much as an errant tick or oil pressure problem with this engine I am confused and more than a little concerned but cheerfully offer to break in a new engine :biggrin:. By the following Wednesday I get concerned and call. The Service Adviser tells me they found nothing wrong with the lifters and a tech from GM Technical Services in the States (I'm in Southern Ontario, Canada) arrived the previous evening and is checking the Tahoe as we speak. He'll keep me informed. That evening he tells me they are going to send all the injectors out to be flow tested on Thursday, keep the car for a while longer. Well at least they've brought in the big guns. Friday afternoon I get THE CALL. It seems they found two injectors that were flowing TOO MUCH fuel and after replacement everything seems to be fine, come and get the Tahoe.
Sorry about the length of this but we're almost done. It's been eight days now and no MIL, the idle is rock solid smooth AND it has started right away EVERY time. So it seems the hard start was caused by injectors flowing too much fuel. Wouldn't an exhaust gas analysis have shown a rich fuel/air mixture to begin with? Anyway as I've read numerous threads with hard starting complaint I hope this tale can help someone. Thanks for listening.

Check out post #2 in this thread as you have the older style injectors. It may be the source of your problem. Also search for threads about hard starting and SCFI fuel injection systems on pre 2000 Tahoes. Good luck.