hey i have a 90suburban 350 tbi and when i start it cold it surges and pushes black but if you hit the gas for a few seconds it idles good, now the second problem is that if your driving it and hit it over half throttle it bogs hard and doesnt go anyfaster but 1/8 and 1/4 throttle work fine, ive replaces the tps and fuel filter so far havent checked timing but it should be fine.... it doesnt pop or anthing out the tbi let me know any suggestions would be good
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
tbi bog
- Thread starter Big_10
- Start date
you need to check and see what your coolant temp sensor is reading.
Plus for starters, you need to scrub the inner bores of the throttle body with a toothbrush and some carb cleaner, I've had that solve all kinds of strange problems.
Plus for starters, you need to scrub the inner bores of the throttle body with a toothbrush and some carb cleaner, I've had that solve all kinds of strange problems.
Thunder
3/4 ton status
Have you checked trouble codes?
bp71k5
3/4 ton status
Are you saying the truck sat for 8 months and now it's doing this? I'd check for bad gas or whether any water got in it.
bp71k5
3/4 ton status
If you replaced the TPS, isn't there some kind of calibaration you need to do for it and then reset the ECM? I don't know what the calibration is, I just heard you had to do something after replacing the TPS.
Thunder
3/4 ton status
I am thinking ignition module. If there are no codes with the driveability problems you are having that is the first thing to check/replace. You can have them tested at many auto parts stores.
Re the TPS. The only adjustment needed is setting the base voltage. With the throttle closed it should be .5 + or - .5 volts.
Usually when you replace one. It bolts in right around the correct setting and requires no adjustment or reseting of the ECM.
Re the TPS. The only adjustment needed is setting the base voltage. With the throttle closed it should be .5 + or - .5 volts.
Usually when you replace one. It bolts in right around the correct setting and requires no adjustment or reseting of the ECM.
ok there is next to no vaccume at the pcv and checking the vaccume is a joke the pcv isnt sucking and if you rev it doesnt change much theres a noticable sucking if you put your thumb on it but maybe 1-5 psi, also if i unplug the spark timing and advance the dist a lil bit it helps alot no surging and takes off ok but still 1/2 throttle bog but it chirps the tires if you 1/4 throttle it quick off the line but if i plug in the spark timing it idles lower and stalls if i put it in gear let me know!
bp71k5
3/4 ton status
Have you checked for a vaccum leak?
jonathon
1/2 ton status
I just did an EGR valve in my mom's S-10(TBI 4.3).. couldn't believe how much better it ran. Since we've owned the idle has always been rough and it would bog under WOT.. doesn't anymore.
For $60 or so why not just replace it? On a full size it looks pretty easy.. at least compared to the S-10 where the EGR was buried on the back of the intake under various lines and wiring
As far as needing it.. I don't know, my understanding of them is somewhat limited.
For $60 or so why not just replace it? On a full size it looks pretty easy.. at least compared to the S-10 where the EGR was buried on the back of the intake under various lines and wiring
As far as needing it.. I don't know, my understanding of them is somewhat limited.
