Engine problems...FIXED!!!!

[86454K30]

Ok, I bought an 88 K5 blazer a month ago with a broken frame at the steering box it ran great. Engine is a 350 TBI with a 700r4 tranny.

So after fixing the frame I drove it a couple times with no problems other than a major exhaust leak.

Here is what I have fixed, new passenger side exhaust manifold, new fuel return line from TBI to hard line as it was leaking and a new fuel filter, also added 3/4 ton, lift and tires.

Now I went to drive it tonight, it spits and spudders trying to give it gas then starts to run fine. I drove it a mile to the gas station and it was running OK...with LOW power. I got gas headed home, VERY low on power, tranny is shifting funny actually had to put the thing in 4lo to get home as it had no power. Engine temp climbed to about 210.

So I get home pop the hood and both exhaust manifolds are glowing red.

Any ideas guys?

 

[kgblazerfive]

running to lean ?

 

[86454K30]

Definitely lean. No codes....which is typical for a OBD 1.

 

[diesel4me]

If there is still a catalitic converter on it,it might be plugged up....try unbolting it and go for a short ride and see if it gains its power back...it could be the fuel pump dying too,just a few pounds under spec can make it run lean,start hard,and have no power...

 

[86454K30]

I am going to test the fuel pressure tonight. It actually does start harder than other TBI's that I have had.

 

[4xcrazy]

I was going to mention, as I always seem to, to check the fuel pressure. Been there, done that, same type of problems you just described, except I never really noticed red glowing manifolds.

Bucking, spitting out the intake, no power, I even drove mine home from San Diego to Phoenix like this because at the time, I couldn't figure out what was up with it, never hit overdrive in the trans, just wasn't enough power I guess to maintain that speed for it.

 

[dyeager535]

Check underhood for bad connectors, etc. Could have damaged something while under hood. Pinched wire?

Did you mess with the TV cable? That vintage tranny shifts aren't related to the ECM/injection.

 

[86454K30]

Thanks guys. I am going to re-check it all tonight and the fuel pressure.

 

[86454K30]

Alright...I think I found part/most of my problem. The vacuum line from the TBI to the charcoal canister was cracked. Runs better but the idle seems to hunt. Got some more checking to do.

Thanks for the help!

 

[86454K30]

Well, runs a little better but still low on power and wants to die when you gas it. Trying to find a fuel pressure guage with the correct fittings.

 

[86454K30]

Checked fuel pressure its showing 12psi. I noticed yesterday that there is some seeping around the fuel pressure regulator. I am going to rebuild it tomorrow. WHat do you guys think about the fuel pressure?

 

[dyeager535]

Exactly 13PSI is ideal for a stock setup, GM spec was 9-13, so 12 is good IMO.

 

[black dawg]

Checked fuel pressure its showing 12psi. I noticed yesterday that there is some seeping around the fuel pressure regulator. I am going to rebuild it tomorrow. WHat do you guys think about the fuel pressure?

does it hold that fuel psi when you load the engine?

also check timing......with wire unhooked. Had one in the other day, with symptoms very close to yours, timing had been set with wire connected (base timing was set at like -15deg) and fuel psi would fall off to about 5 psi under load.

 

[86454K30]

Thanks for the reply. I will check wednesday night the when I get a chance to work on it again.

 

[454Sub]

Check for a plugged cat or muffler too. If you havent already. Me and a buddy were working on his Ford Taurus and it did basically the same thing. Well come to find out the intakes on them are plastic, and it caught fire . So we hacked the 3rd cat off (why they have THREE Il never know) and it runs like a champ now

 

[82355]

Yeah, I would recommend checking the cat as well.

Martin

 

[Jester1]

Yeah, I would recommend checking the cat as well.

Martin

Checking or REMOVING unless you are in on of those states.

 

[86454K30]

The cats been replaced with a hi flow cat at some point but, I will check that too.

 

[86454K30]

ok....Here is what I came up with:

Fuel pressure good.
Fuel pressure regulator leaking A LOT: rebuilt throttle body...no change
I checked the timing after the throttle body rebuild it would retard, advance go back to zero, it continued to repeat this.

I ordered a new distributor from Skip White Performance....$63.50 shipped...problem SOLVED! Blazer runs great!

 

[magik235]

Excellent outcome