1991 k5 lacking power?

[91GMCSuburban]

i am not saying the gears are the problem but the tune up stuff is about 75-80 dollers total. and gears are 300-1000 for used axles or new gears. the cheeper fix would be the one i do first. then when sure running good do gears.

I do agree with this and would do and have done the same thing. But since I've been there, I now what's coming.

Check vacuum lines, clean tbi (maybe even rebuild) and clean the injectors.

Also (and this is not likely because it would be a free fix), reset the TPS. Unhook the battery to reset the computer, once reset, turn the key to "ON" and then press the thottle pedal from zero to full throttle 2 or 3 times. If it had been replaced and not reset like this... you may get lucky.

 

[dirtwarrior17]

ok, i'll translate for ya... not too hard, 1 letter..

we Put a 4" lift with 35's underneath it and he said while driving in the highway he had to have the pedal to the floor to get to 65?

lets look at the key phrases here.... "pedal to the floor" and "to get to 65"

sounds like a 0 to 65 issue to me.. and it certainly doesn't sound anything like a tranny issue... it definitely wants a gear but i'd bet the farm its got a tune up issue causing the majority of that prob.. i'll find out saturday....

When he says to the floor to get too that also can be gearing... My k5 would do the same thing, if you keep it at around 3/4 throttle it gets real close to 65 but not enough to shift especially if it is slightly up hill. When I hit hills on the highway i would have to floor it to maintain 65. he could have been exagerating because the power difference is suprising... i thought my stock motor would have more up top. We could both be right so its pointless arguing until he tells us the rest.

 

[ryoken]

Also (and this is not likely because it would be a free fix), reset the TPS. Unhook the battery to reset the computer, once reset, turn the key to "ON" and then press the thottle pedal from zero to full throttle 2 or 3 times. If it had been replaced and not reset like this... you may get lucky.

nice tidbit haven't gotten that far in the service manual yet.. saved for future use.. thanks.

 

[2Dogs]

Where is the owner of this thread for some desperately needed clarification?????

 

[wraenking]

sorry boys. been watching the tube. the owner is a mechanic for ups and he hasnt owned a blazer in a while. hes all ready to to do the tune up, but he asked me to see what i can found out here first. when he said he needed the pedal to the floor, it sounded to me like it was a power problem.

take my dumb ass for example. i thought this new engine i got was lame, turned out i didnt have the throttle set right, and now im zooming with some real power.

there are so many people that run this set up without re gearing, so i was wondering what you guys thought



if i didnt just make sense, im sorry, im half asleep

 

[dirtwarrior17]

EDITryoken you were right.

sounds like a fuel system problem and the fuel filter seems like it would be the culprit. If it doesn't change anything then try some new injectors... i know they get clogged pretty easy... my bros are dripping on his 91 jim.

Efi is tricky this way.... i would hook up winadl and see what the problem is.... could be tps like was said earlier.

 

[2Dogs]

ryoken was right.

sounds like a fuel system problem and the fuel filter seems like it would be the culprit. If it doesn't change anything then try some new injectors... i know they get clogged pretty easy... my bros are dripping on his 91 jim.

Efi is tricky this way.... i would hook up winadl and see what the problem is.... could be tps like was said earlier.

Wutchu mean 'ryoken was right' ??? Check post number 3 You Red-ding boys..

 

[dirtwarrior17]

meant to say ryoken, you were right.

 

[2Dogs]

meant to say ryoken, you were right.

Just f'in with you - we will not know the answer until they start trying things or explaining the symptoms. Even then people rarely post the solution or root-cause of the problem....

 

[ryoken]

i'll make sure to post back up with what we find..

 

[goldwing2000]

I'm surprised nobody mentioned another obvious thing to check: the air filter.

If the engine is choking, it doesn't matter how much fuel you dump into it.

 

[91GMCSuburban]

because that would be too easy...