1989 s10 4.3 TBI rough idle and surging
 

Ok I have looked though alot of posts and Googled the heck out of this issue...
I have a 1989 s10 blazer 4x4 with a 4.3 TBI, Vin Z.
The issue is that it has a really rough idle and is surging in park and when i am stoped in drive, I can drive it but at red lights i have to put it in nuteral. I can smell too much fuel and it is puddeling up in the TB, Also just recently it is grinding when I start it (I think the started is going bad.) and when driving there is a lose in power like some one just flips a switch and says no more then the switch is fliped againg and it goes on down the road. things that have been replaced inclued

MAP Sensor
MAP Sensor Pigtail
TPS Sensor
Injectors
Plugs and Wires
Cat Converter
Fuel Pump
EGR Valve
Engine and Tranny where replaced about 10 years ago and have less the 70,000 on them.

I am loss as to what the issues are caused by :icon_shrug: but any help is greatly apperciated.

Tonight I took some time to look over things but being that Im not a machinic Im a bit confused, The vacuum hose that goes to the PCV Valve and TB was Wet? The TB vacuum port was full of juck and the pcv valve was nasty too. I cleaned both and still no help with issues. the valve cover is pretty full of stuff too. I was also looking at the EGR Control Solenoid and with the vacuum line that goes to the TB off the engine revs up high but smoother, Could my issue be a bad EGR Soleniod? I will look into the prices and maybe get one first of next week.

Check the coolant temperature sensor. If it's reading low it will tell the computer to inject more fuel than is necessary. Also make sure your EGR is nice and clean. Those are the first two things I would check.

Sorry I didnt update that I put in a new coolent sensor last night, The one that goes to the computer not the one that goes to the gauge. As far as the EGR I put the new EGR Valve on but should I change the EGR Sensor? Could this issue be the fuel pressure sensor? If so where would I find it?

How about the O2 Sensor also controls fuel mixture. Things that come to my mind are IAC, Temp Sensor, O2 Sensor & EGR Valve. Make sure you have no vacumn leaks on the TBI.

I went ahead and got a IAC valve and put it in but it didnt help. I took it to the mechanic and the looked at it and told me it was the computer, so I replaced the computer and that didnt even help... looked to see if there are any vacuum leaks and I found one, I used some tape on it to see if it would help but vary little improvment. I am so lost as to what it could be... I have an appointment with a diffrent mechanic this coming teusday... any more ideas I could try? thanks for all the help so far.

Check the spark plug wires, there may be arcing, look for cracks or crusted burnt dots on the wire near the end. If the inside of the boot on the plug has no dielectric grease (dry) this will promote arcing around the plug ( this is hard to see at night, use the water test to expand the arc)

I was having this same exact issue, I scoured the web for days, this forum and many others, and turned nothing up. I talked to anyone I thought knew S-10's well enough and nothing. Finally I took it to go see some old timer mechanic and as soon as he saw the puddling fuel at the TBI he said you have bad seals. He ordered a TBI Rebuild Kit from Napa and a couple hours later. I was good to go - rough idle. and stalling out at long lights is now gone.

95 chevy blazer runs good at high speeds but wants to stall and surgers at idle

Still waiting on the Blazer replay

Well u might want to try the Ignition switch, Duralast/Ignition Switch (LS442) | 1986 Chevrolet S10 Blazer 4WD 6 Cylinders R 2.8L TBI | AutoZone.com I have a 86 blazer and its located on under the dash on top of steering column on mine. im sure yours is in the same place! you will have to drop your column to get access to it! This part only cost about $15.00 or so! I heard if its bad it can cause alot of problems! good luck and please post your finding, thanks

Idle too fast. Rough at start up.
 

My 1989 S10 Blazer 4.3L V6 was idling too fast and rough at start up. While driving, I could take my foot off the gas and it would cruise at 30mph. It has 345,000 miles. Tried everything. Mass air sensor, idle speed sensor. Took throttle body off cleaned it very well. No change. No vacuum lines broken or cracked. Was advised to replace intake manifold gasket and check distributor. Replaced distributor and intake gasket. One intake bolt was broken, gasket in bad shape, distributor pretty worn out. That did it! Runs just fine now!

Old thread but making progress.
 

Sorry to bring back an old subject, but I finely got around to working on my poor old Blazer again and I am trying to bring it back to life again after almost 2 years of sitting.

A few days ago I rebuilt the Throttle Body as one of the posters had suggested, and today I went to the auto part store and got a new battery. While I was there the person helping me put it in noticed that I had a Spark Plug Wire loose.

Well I put that back on and it is running alot better after the above fixes but it still has a inconsistent idle and alittle rough. So I bought a new Cap and Roto. I will try to put it on tomorrow when I get off work and post again as to the results.

In the mean time are there any other suggestions?

Thanks again for all the help. :icon_lol:

Possibly check out the TPS (throttle position sensor) or the IAC valve

I replaced those as part of the troubleshooting process before but I don't think I adjusted them. I read that the TPS is not adjustable on this year, is that true? How would I adjust the IAC?

Also I replaced the Distributor cap at it didn't help, I also ran a rod through the CAT as it had been sitting for a while and I wasn't sure if it might have been clogged...

It runs fair now, but the idle is still inconsistent and wants to bog out. Also there are strong exhaust fumes which doesn't seem normal.

get a pack of vacuum caps and cap the line going from the EGR control solenoid to the EGR...and also at the TB that goes to the EGR control solenoid....see what that does.

1991 S10 Blazer missing/surging
 

I finally figured my blazer out.....I've read these threads about the 4.3 TBI surges and missing at idle and i have done what everyone else has done. I replace EGR plugs and wires this and that and i found out that after cleaning my new egr, i noticed my egr port on the intake was complete clogged. I cleaned it out and even with a timing adjustment needed, HUGE difference. I am missing a motor mount on the drivers side and i still cant feel it run. I hope this helps anyone out there