03 Yukon with starting issue

[kev92gt]

Well made a trip from St. Louis to Topeka ks usually about 5 hours so about 1/2 way we stop for lunch. Temp was 105 outside and after letting it sit for about a hour it wouldn't start but was cranking. On second try i gave it a little gas and it stumbled real bad but did start. I'm not sure where to start but it is acting like my wifes trailblazer when i was told it was the crank sensor. Is there 1 or 2 any links would be grately welcomed. Thanks in advance

 

[bkboatnsleds]

Bad fuel pump would be my 1st guess.. Next time it wont start bang on the tank and see if she fires.

 

[kev92gt]

Thanks for the reply a buddy said the same. My mpg went from 21 to 16 i was just happy to make it home. Is there a upgrade pump or just stick with stock Ac Delco?

 

[bkboatnsleds]

Pay the $ and stick with OEM - I didnt - and I'm sorry... and I';m not the only one..

See this post that just started too:

http://www.tahoeyukonforum.com/forum/showthread.php?t=42201

 

[kev92gt]

We just tested the psi at the rail and it was low so new pump it is. Confused on what pump to get. acmu1321 or acmu1378 google just confused the crap out of me.

 

[kev92gt]

Help please which pump?

 

[TheFuzz]

1378 is for the 5.3 flex fuel engine, 1321 is for the regular 5.3 gasser (non-flex fuel). Order accordingly.

 

[kev92gt]

thanks its a non flex. Autobone is trying to tell me acmu1615.

 

[TheFuzz]

1615 is the pump only without the fuel sending unit. I'd pay the extra few bucks and get the whole assembly - if the sender goes out then you'll get fuel but your gas guage will be all over the place (I ran my '99 Envoy out of gas a couple of times because of that issue...whoops). Better to do the whole thing and only drop the tank once.

 

[kev92gt]

1615 is the pump only without the fuel sending unit. I'd pay the extra few bucks and get the whole assembly - if the sender goes out then you'll get fuel but your gas guage will be all over the place (I ran my '99 Envoy out of gas a couple of times because of that issue...whoops). Better to do the whole thing and only drop the tank once.

Thanks if you ever in St. Louis I owe you a drink of your choice. I found a ac pump on ebay for 179.98 to my door got today and its the real deal.