Jimmy acceleration problems

[BlazerLT]

I wonder if there are any check engine lights.

[Bagel191]

Ill check the EGR and let you know.

THERE IS NO CHECK ENGINE LIGHT ON

[Bagel191]

Checked EGR still does the same thing

[BlazerLT]

Hmmm.....

Still makes me think the fuel pump is weak.

[Eagle 25]

I have similar problem on my 89 Jimmy (4.3L / 145 k miles.) Haven't been able to solve it yet. Last recommendations was to replace engine. If you get yours solve - please let me know so I can try the same solution.

[greginportland]

My 93 4.3 Vortec
was behaving very similar - seemed to idle find, but when accelerating it coughed and eventually got so bad that I can only drive 10mph.

I replaced:
fuel filter
Throttle Position Sensor
EGR Valve

ALL FOR NOTHING BECAUSE THE PROBLEM WAS THE SAME!

So I took it to a mechanic and he told me it is my CPI unit.
Cost me $120.
Now I am awaiting my CPI unit from an ebay seller ($180 vs. usual +350).
I don't have the experience to tell you that's your problem but it seems worth looking into. Can't tell ya how to diagnose it though.

Can anyone tell me why I can't find a Throttle Valve Cable near the accelerator/cruise control cables on the same lever?


greg

[blazes9395]

Originally Posted by greginportland

Can anyone tell me why I can't find a Throttle Valve Cable near the accelerator/cruise control cables on the same lever?


greg

The transmission is electroniclly controlled, there is no TV cable for these transmissions.

[BlazerLT]

Originally Posted by greginportland

My 93 4.3 Vortec
was behaving very similar - seemed to idle find, but when accelerating it coughed and eventually got so bad that I can only drive 10mph.

I replaced:
fuel filter
Throttle Position Sensor
EGR Valve

ALL FOR NOTHING BECAUSE THE PROBLEM WAS THE SAME!

So I took it to a mechanic and he told me it is my CPI unit.
Cost me $120.
Now I am awaiting my CPI unit from an ebay seller ($180 vs. usual +350).
I don't have the experience to tell you that's your problem but it seems worth looking into. Can't tell ya how to diagnose it though.

Can anyone tell me why I can't find a Throttle Valve Cable near the accelerator/cruise control cables on the same lever?


greg

Remember to replace the nut kit as well.

Get it all done in one shot so you won't have problems in the future.

[greginportland]

OK IGNORE THE ABOVE POST.
I discovered on another post that I must go to GMC dealer for the nut kit. Problem is the guy wan't very knowledgable, so I am going to attampt to find a # for the "internal line kit" - anyone know that?
I am not sure which clips I need to order. I have a few #'s I need to find a site w/ pictures to verify.

[greginportland]

# for the "internal line kit" - anyone know that?

GMC called me back and tried to clarify this w/ me:

the internal line kit for a 93 gmc 4.3 w w/ CPI -
is this referred to as TBI Fuel Feed or TBI nut kit?

I thought TBI had nothing to do w/ CPI, but he says this is what I need, for $80.41. part # 17112705

any tips?

[BlazerLT]

Go to the dealer and ask for the nut kit which is the internal fuel line kit for the CPI or CMFI injection system.

Better yet, walk in there and show them.

[greginportland]

Originally Posted by BlazerLT

Go to the dealer and ask for the nut kit which is the internal fuel line kit for the CPI or CMFI injection system.

Better yet, walk in there and show them.

Do I need to be concerned about resetting my timing - after I put in the CPI and nut kit?

Does "IF IT AIN'T BROKE DON'T FIX IT" applly to my distributer cap & rotor, and plugs? These have not given me trouble but are probably from 1993 or late nineties at best?

gratzi

[BlazerLT]

Originally Posted by greginportland

Do I need to be concerned about resetting my timing - after I put in the CPI and nut kit?

Does "IF IT AIN'T BROKE DON'T FIX IT" applly to my distributer cap & rotor, and plugs? These have not given me trouble but are probably from 1993 or late nineties at best?

gratzi

It would be foolish to fix the CPI and nutkit and have the fresh injection system being hampered by a vehicle that han't been tuned up properly.

Do a complete tuneup with cap, rotor, wires, AC Delco plugs gapped properly, PCV valve, fuel filter, air filter.

Also note, might want to do a cooling system flush with a new Non AC Delco rad cap along with a transmission flush and filter change and to drain your tranfer case and differentials and fill them with fresh fluids.

It might seem like a lot, but you can do most of it yourself and your truck will be completely perfect and performing to its maximum potential and will lengthen the life greatly.

Also, would be best to time the truck now AFTER everything is tuned up by pulling the brown and beige timing wire from the PCM under the dash, timing the veicle with a timing gun to zero, and then reconnecting the wire to the computer.

Be mindful that you might have some carbon coming out of your newly tuned up engine and you will have to clean the EGR valve out a couple of times when the excess carbon is released from the engine.

Might as well buy a couple of EGR gaskets just to make the cleaning easier.

[greginportland]

[quote=BlazerLT]...Do a complete tuneup with cap, rotor, wires, AC Delco plugs gapped properly, PCV valve, fuel filter, air filter.

Also note, might want to do a cooling system flush with a new Non AC Delco rad cap along with a transmission flush and filter change and to drain your tranfer case and differentials and fill them with fresh fluids.

Also, would be best to time the truck now AFTER everything is tuned up by pulling the brown and beige timing wire from the PCM under the dash, timing the veicle with a timing gun to zero, and then reconnecting the wire to the computer...

THANKS for the advice man. I purchased the the above parts and cheap AutoLite plugs.

Wanted to take care of that lastnight while I wait for my nut kit, but discovered some crackhead broke my window (probably saw me w/ my tools over the weekend). So I had other things to attend to.

The higherpowers playing a joke on me? The anti-GMC gods raging?

I'll try to get the truck running this weekend then figure out the flushes/fluids.

g

[BlazerLT]

Take the cheap autolite plugs back and do the job properly with GOOD plugs.

AC Delco plugs are really cheap and are the best for our trucks.

Model # for your year is CR43TS gapped at 0.045

Don't go cheap on your truck parts or you will be sorry.