Hey guys, I don't have a camaro, but I am having issues with my TBI 350 in my 89 Suburban V1500

I have tried other forums and it hasn't helped much. No body seems to know much about these systems. Either that, or they aren't online!

Ok, here it goes:
Started out a few months ago while towing. The truck would lean out and heat up a bit. While driving normal, the temp was fine, but started using fuel like crazy. Gong up hills, I could smell a strong exhaust/burning smell.

Fast forward a few weeks, and the truck dies at stoplight. Got her restarted, and limped her home, bucking and jerking the whole way.

I replaced the fuel pump, filter, and did a complete tune-up (cap, rotor, plugs, wires, 02 and CTS) Immediately started up, and ran a lot better than it did before.

It ran ok, but lacked power at takeoff, still hesitated and had a slight misfire at idle. The exhaust was nearly rusted off, so I replaced everything, including the cat, and ran a whole 3" system from the Y pipe back.

Still ran rough. Checked timing (right at 0 with the connector disconnected), vacuum (steady 18 or so) and everything checked out. Unplugged EGR and blocked off the Vac hoses and ran a little better, but still the same symptoms.

Got the throttlebody cleaned out, and noticed one of the injectors was dripping pretty good, so I replaced both injectors, and the fuel pressure regulator. Ran a bunch better, but still has a slight miss at idle, and still hesitates a little right after take off. Still lacks power throughout the RPM's.

During those 2 weeks, I've checked the TPS (.61 at idle, and 4.33 at WOT for Voltage and goes steady up and down) replaced the IAC, MAP, all the vacuum lines, checked the grounds.

So I am stuck with slight miss at idle, loss of power through the RPM's. And It still smells rich at times. Every once in a while when I get on it, it backfires out the exhaust when I let off.

Any ideas on what is going on?? Any insight would be great!!! Thanks!
Ryan

 

You have good spark? Maybe you have a weak coil or bad Ignition control module

 

both of those are new when I did the tune-up (forgot to mention those) but I guess I wouldn't completely rule those out either. I may pull those and get them tested at least.

What does spark-knock sound like?? I am getting a wierd sound right after takeoff from my exhaust, which is a 3 inch setup with a glasspack. right at takeoff it has a nice deep grumble, but then it gets really loud, I'd have to say about 1500rpm, then when I hit around 2K rpm it goes away and quiets down again to what I think the setup should sound like. Thought it was just my exhaust, but not so sure. It always does it at the same RPM regardless of my speed. I have no tach, so these are ballpark figures.

I squeezed my EGR last night to see if it was moving freely, and it feels like it is grinding when I ry to move it up and down, like its not moving freely. Would a faulty EGR still cause problems even if it isn't hooked up??

 

Original distributor? They are notorious for going bad, specifically the pickup coil.

 

yes the original distributor. Would it help to replace just the pickup coil? or the entire distributor? Another question, when I buy a distributor, does it come with a pickup coil?
Thank
Ryan

 

Just as easy to replace the whole distributor, especially if it has significant miles on it.

A replacement distributor will come with a pickup coil.

 

About 150K on the truck, everything is original, but I will replace the distributor. I called the dealers service dept and they also suggested the distributor after I explained what was going on. They said they would charge me 100 bucks to take a look, but then if it is bad, I would have to shell out another hundered some dollars for a new distributor. If it fixes my problem, then Ill save myself 100 bucks. If its not, then at least I'll have the peace of mind that it does have a new one.

Any tips on what to set the timing at for a stock truck with mild exhaust mods? I gues I could play around with it a little bit to see what would work best.

Thanks guys

 

I rechecked the timing tonight, looked good but the tab was dirty, so I wiped it off, rechecked and sure enough, It was retarted by a few degrees. I reset the timing to 6 (ran the best) for now, and it sure idles better. I didn't get a chance to test drive, but I will try it out tomorrow on my way to work. God that distributor bolt is a pain to get too!!

 

Yeah normally you need a distributor wrench to get to it. YOu should be able to pick one up at o'reillys or autozone or advanced or napa depenign on what ya got where your at

 

I did have a distributor wrench, but with that metal coolant hose on the back of the intake manifold, even that wrench was a pain!! I got it, but was tough. Ill let you know how everything turned out!

 

New update, driving on the highway, the truck started bucking, missing and backfiring. I couldn't get it over 45 but make it home. Now, even just taking off from a stoplight, it hesitates like it originally did before all this work, and idles as bad as it ever did.

I pulled the dizzy cap and saw red dust, and while inspecting the pickup coil,noticed that it rotated about 1/4 turn one way and another. Not sure if they are supposed to move at all, but if they are, this one isn't moving right, because it feels like it is grinding (not a smooth rotation). The windings look really rusty/dirty.

I know what the red dust means, but is the pickup coil supposed to move like this??? Thanks!
Ryan