'92 S10 Blazer - Start/Hesitation Problem

[daves10blazer]

Any suggestions?

I have a '92 S10 Balzer, 4.3 Vortec engine (spider injector), 145,000 miles.
Recently I have a few problems:
1) Hard start - I have to floor the throttle while cranking to start it up.
2) Once started it idles fine - but pulling away from a stop and it will hesitate like it's missing or starving for fuel. Floor the throttle and it will work itself out. Once driving at a steady rate and transmission shifted into overdrive it will chug off and on. All this hesitation and chugging seems to get worse once the truck is warmed up.

Last but probably not related to the above
3) Leaking oil - which appears to be a rear main seal.....

For 1 & 2 I am thinking a fuel problem. I only mention number 3 because everything seemed to happen at the same time - or very close to the same time. I noticed the oil leak getting worse and now the hesitation and start problem is getting bad.

Any suggestions?

(plugs, wires, dis. cap, rotor are all good; EGR valve changed last year; new PCV; fuel pump and sending unit about 2 years old)

[shanes76]

I just had the same hesitation problem on my 94 jimmy, I had to replace the fuel return lines inside the upper intake because they were leaking and caused a hesitation like symptom when I would take off from a dead stop, wasnt as bad when cold but the longer it ran(getting up to temp) the more gas it was leaking inside the plenium and I was getting to much gas for the slow speed. Underneath the Vortec plastic on top of the intake is a round black piece with a plug on it, take that out and get a flash light and look around inside and see if the drivers side of the plenium look clean on the inside anywhere, also check on the passenger side, if the drivers side is clean- the return lines are bad(lines cost 60.00) if the passengers side is clean probally the regulator(50.00) Also check your oil for gas - I had some gas in mine and that might have something to do with the oil leak cause the gas would thin out the oil. I am not saying this is what the problem is, but its the same symptoms I just went thru and I got alot of help on this site. MT is a very good guy to get help from and I'm sure he will help out you. I also cleaned my EGR valve, IAC valve. But it was mostly my return lines, also mine would start great the first time, then after shutting off it would take more to start it- guess all the extra fuel was kinda flooding it out.

[Gabe25]

First thing is you need to check your fuel pressure to ensure that its not leaking. With the ignition switch on. You should have 61-65 lbs of pressure. Engine running should be 60-66 lbs pressure, pending on the load. Ignition switch off, your pressure should not drop below 55psi within 5 minutes. If it drops below 55psi before 5 minutes. You’ll need to check to see if your injector Fuel regulator, and Nut Kit for leaking. If no leaks are found, Then do a full fuel pump test. A quick test is to block off the return line and see if fuel pressure comes up to 75-85 lbs. Post back your findings.

[daves10blazer]

shanes76 and Gabe25 - thanks for the advice. I will try to check it out this weekend and get back to you.