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I recently bought a '99 4 door 2wd for my girlfriend and the baby. Body and interior are 8/10, so I couldn't pass up the deal since we are on a tight budget and needed a small suv. I'm very familiar with S10/blazer vortec platform. Between my dad and I, we've owned 4 over the last 20 years.
The guy I bought it from isn't a gear head. His mechanic told him that the "CADDY WAS PLUGGED", making excuse for the lack of performance. As soon as I got it home, I took it straight to my exhaust guy and had him punch a hole at the front of the catalytic converter, and with both of our eyes, the insides of the cat was like almost new. So we patched it back up and I took it home an did basic maintenance, oil and filter, fuel filter, new plugs, cleaned the MAF and checked all connections, already had a brand new clean air filter, fresh full tank of gas with Lucas injector juice, and swapped the EGR because it was throwing 404 code. Immediately the SES light went away on its own. I've been using a professional scanner that I borrowed from one of my friends to help with diagnostics, but I can't seem to source out the acceleration issue it's having.
If you whomp on the pedal from take-off, It lazily accelerates to just over 3grand on the tach and will sit there without shifting until you let off the pedal, and will do pretty much the same in 2nd, and will surge or buck in 3rd at around 3grand. It'll idle almost perfect around 630-637rpm's, and rev quickly if you stab the pedal, but the feeling I'm experiencing is like it's choking for fuel(not enough) when opening the throttle any more than 25% pedal. I'm use to trouble shooting issues like this on motorcycles, but not late-model vehicles with excessive amounts of emission devices and sensors.
I saw here on another thread that another guy had a very similar description of issues, he resolved it by retarding his time from 20* to 6* at idle, but these years have a fixed setting on the distributor hold down, you cannot manually adjust the timing. I'm at a stand still with this thing, I searched all over the inner and outer webs for answers, I can't find any help. I'm a do-it myself'er because I can't afford to take it to a shop. I work very well with being pointed in the right direction and usually manage to resolve the problem with minor tech assistance/advice. If anyone knows, heard of, or experienced similar issues, feel free to chime in. I will greatly appreciate any and all info. Also, if there's another thread that exposes something along these lines, by all means drop the thread link in a reply if that's possible. I like to read other people's dilemmas and compare...
https://www.alldata.com/us/en/suppor...pression-tests
Check for restricted exhaust using snap test on a cylinder. If high reading, do snap tests on more cylinders on same cylinder bank to confirm. Sounds like plugged exhaust somewhere. Read especially beneath Example 2 in linked article.
Another way to check on engine breathing is the MAF sensor reading will be very low with plugged exhaust at full throttle 1-2 shift (happens about 4900 rpm).
Or you an just pull out pre-cat O2 sensors for both banks (on temporary basis) and see if that cures the problem.
FYI position of distributor has nothing to do with ignition timing on these. Position of distributor is called cam sensor retard and it should be zero +/- 2 degrees. Ignition timing is determined purely by the Crank Sensor and the PCM (with it's sensor inputs).
https://www.alldata.com/us/en/suppor...pression-tests
Check for restricted exhaust using snap test on a cylinder. If high reading, do snap tests on more cylinders on same cylinder bank to confirm. Sounds like plugged exhaust somewhere. Read especially beneath Example 2 in linked article.
Another way to check on engine breathing is the MAF sensor reading will be very low with plugged exhaust at full throttle 1-2 shift (happens about 4900 rpm).
Or you an just pull out pre-cat O2 sensors for both banks (on temporary basis) and see if that cures the problem.
FYI position of distributor has nothing to do with ignition timing on these. Position of distributor is called cam sensor retard and it should be zero +/- 2 degrees. Ignition timing is determined purely by the Crank Sensor and the PCM (with it's sensor inputs).
Good luck
got it, thanx! I'll try the o2 deal tomorrow afterwork and go from there...
Did you check the pre-cat? If so, I'd look into the trans/torque converter.
You know what, I've been suspecting the pre-cat. It would make sense why it feels like a plugged up flow, but the big cat doesn't look bad. It's definitely not trans related, it's a flow issue.
You know what, I've been suspecting the pre-cat. It would make sense why it feels like a plugged up flow, but the big cat doesn't look bad. It's definitely not trans related, it's a flow issue.
Remember that exhaust could be plugged elsewhere in the system. exhaust pipe, muffler, etc. But cat converters are most common.
Remember that exhaust could be plugged elsewhere in the system. exhaust pipe, muffler, etc. But cat converters are most common.
Ya, I've been aware of that recently now that I have a child and am forced to drive newer vehicles. I wish I could afford to just buy her a new car for her and the baby, and let me drive my classics and bikes, but that's not reality. The last 3 vehicles I acquired in hopes of them being suitable for family toting, my favorite was my '93 caprice wagon. The only problem was the previous owner let some junky mechanic fiddle with it and messed up a bunch of stuff under the hood, and rat nested the wiring instead of fixing it properly. I spent the entire year I had it chasing gremlins. I was forced to sell it. Made no money on it. But that had cat issues and a plugged up Flowmaster. I dual exhausted it from the manifolds back with long glass packs. Sounded tuff, but never got it to run right.
Remember that exhaust could be plugged elsewhere in the system. exhaust pipe, muffler, etc. But cat converters are most common.
Ya, I've been aware of that recently now that I have a child and am forced to drive newer vehicles. I wish I could afford to just buy her a new car for her and the baby, and let me drive my classics and bikes, but that's not reality. The last 3 vehicles I acquired in hopes of them being suitable for family toting, my favorite was my '93 caprice wagon. The only problem was the previous owner let some junky mechanic fiddle with it and messed up a bunch of stuff under the hood, and rat nested the wiring instead of fixing it properly. I spent the entire year I had it chasing gremlins. I was forced to sell it. Made no money on it. But that had cat issues and a plugged up Flowmaster. I dual exhausted it from the manifolds back with long glass packs. Sounded tuff, but never got it to run right.
UPDATE EGR open performance code keeps popping up after I've cleared it from the scanner. It has a brand new egr valve with the screen gasket. I attempted to poke through the passage ports to make sure anything wasn't blocking the flow. The ports don't even look that dirty. I'm stumped, don't know what else to do...
'99 problems, but the blazer is just 1!
