Surging ?????

[mayleke]

I have a problem with SURGING ?
Let me give you history. I have just completed installing a new (REMAN) into my '84 Blazer it came with a 305 and I replaced it with the same like size and type. All went very smooth with exchange and Blazer has been running great for 2 months since change over.
Two days ago I was driving up a long and steep hill and was very low on fuel. I thought that the Blazer was running out of gas as it was surging like it was out of gas and totally empty. When I topped out on top of hill I pulled into gas station and filled up. Problem seemed to be gone.
On my way to work today Blazer did the same thing except I was on level ground. It started to surge like it was out of gas and or I was losing an electrical connection. I did not lose lights, my tach did jump during this time but all other systems on Blazer seem to work fine. After about 10 minutes it stopped and Blazer ran fine the rest of the way to work.
I guess I will start the process of elemination i.e. check fuel filter, fuel pump, carb, and all electrical connections.
DID THIS EVER HAPPEN TO ANYONE AND WHAT WAS YOUR PROBLEM. OR DOES ANYONE FEEL THEY HAVE A VERY SOLID LEAD AS TO WHAT THE PROBLEM MAY BE.

 

[lamberthkp]

dont know if yours would be the same thing but when i got my blazer, after about 1 month it began surging but mine would do it mostly when i had all the electric stuff on at first, i hunted through the truck never could find out what it was for about a year . well one day i was putting a new hotwire from the selonoid to the bat to see what that did, well when i touched the selonoid isaw a small crack ended up all that time i had a short in the selonoid all that time . but that is what my problem with surging was. GOOD LUCK!! HOPE YOU FIND IT FASTER THAN I DID.

 

[Hogback Fabrication]

Surging can be caused by running very lean. I would replace the fuel filter first.

 

[AV8]

I had a similar problem that turned out to be the fuel filter.

 

[mayleke]

Thanks for the info Devil Dawg. I will look into that when I run my electrical.

 

[mayleke]

I agree that the fuel filter is the first place to look. cheapest, easiest and quickest fix. (AV8) Don't tell me you are a Harrier mech? I spent 22 plus fixing lawn darts in Yuma.

 

[AV8]

Naw, I did work on a few while I was in Iwakuni....not too fond of them. I did most of my work on F-18's.

 

[mouse]

My guess is that the sock in your tank has something stuck on it from when the tank was almost drained. Its a bugger to change.

 

[mayleke]

Okay this is what I have done to correct problem with no luck. I have replaced the fuel filter, fuel pump and solenoid idel stop and truck is running worse then ever. I mean everything I did was a very easy repair and dosen't take a brain surgeon to do. I know that all was done correctly and according to specs. I also double checked the old and new fuel pump to ensure I was getting enough gas to carb. I was getting between 1/2 and 1 pint of gas every 15 seconds and that is per the manufactures recommendations.

I could hardley get the truck to fire at first, felt like it was flooded. But after it started it was backfiring like crazy and took some time to keep it running. I finally got it to idle at 600 rmp while warm and stay running. But when giving gas it was backfiring and wanted to quit like it was starved of gas or air. I do have a new motor with less then 2000 miles on it and thge carb is original with 97000. Ithink the carbs internal parts are just worn out and I need to replace the carb. I do not want to put on after market parts. I like to replace with OEM replacements. Does anyone know where I can get a remand carb or possibly where I can send my carb in for a total overhaul. I know I can rebuild mine for 20 bucks but I want it broke down and blasted and all new internals.

I

 

[diesel4me]

sounds like ignition...

You might have a bad pick up coil,or ignition module,ignition coil,or faulty 12V wiring to the HEI ..either can mimic the symptoms your describing..carbs dont usually die all of a sudden,unless the float sinks or the bowls crack..if your sure the plug wires are good,and all the steel and rubber lines from the tank to fuel pump are good(rubber one near the tank often LOOKS fine,but collapses internally after 10+ years!)...then I'd say its more ignition related than fuel..

Check the advance weights in the distibutor too,see if they are rusted ,or too loose on the pins..

I had one truck with similar symptoms stump me for weeks..I finally noticed one screw holding the ignition coil into the cap had "punched thru" and was exposed to the rotor!(happens a lot,OEM screws are TOO LONG for many aftermarket dist caps!)...it let the spark jump to ground there,rather than fire the plugs somtimes..other times it ran perfectly!..it was more of a problem in wet or damp weather,but did it under all conditions sometimes too..