Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - tbi 4.3 issues,
Thread: tbi 4.3 issues,
View Single Post
  #1 (permalink)  
Old 08-31-2009, 09:12 PM
fast68's Avatar
fast68 fast68 is offline
likes chevy trucks & boobies
 
Last photo:
Join Date: Oct 2005
Location: IL
Posts: 1,970
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
tbi 4.3 issues,

ok we have this 1993 pickup at the shop once again with the same complaints as it origially had months ago of it not having nay power and not able to accelerate hardly at all

i noticed that it just start up then stumbles and dies, yet it will rev up and seem ok, out of gear anyways.

the dying at idle may just be carboned up IAC motor in which is no big deal i will check that tomorrow and clean it. just to eliminate that cuz im sure no one has checked it, probably ever.



now,, i have owned and worked on billions of these tbi chevies and have found that they are extremely temperamental about fuel pressure,

if its too low even by a tiny amount then they just have no power or wont run, or both...

we had a 92 astro van in the shoop here a couple times like this, having the lack of power, as this 93 does,

except for it would idle, but not quite perfectly, or like it should,

even though the spray pattern on the van looked like it was great and spraying gobs of fuel it had no power at all and wouldnt acclerate like this pickup is doing.

we finally just had enough of it and put a new pump in it and bam! it was like brand new strong awesome great and finally done., and has been great ever since.,

well this pickup out here now, we did put a new pump in a couple months back

also new filter and new wires plugs cap rotor and all that.


so it is kind of confusing this time...

also it has a new egr valve in which were problematic commonly on these tbi engines as well.


only thing i can think is faulty new pump


and theres no way to check pressure on these tbi engines they didnt put a test port valve on them for some unknown reason.


so...



what do you think?

maybe something im overlooking or have forgotten to check ?

or bad replacement fuel pump it must be ?(if not a restriction in the pressure line somewhere, or pressure leak inside the tank)



thanks
Reply With Quote