MY 5.7L is having issues.
My 1988 Suburban with the 5.7L starts and runs good but after it's been driving for a
few miles it starts to cut out like it's not getting enough fuel, but if I step on it it
downshifts and runs fine until I let off then it starts cutting out again. When I come to
a stop it idles just fine but has a bit of a problem taking off. If it sits for a while it runs
perfectly for the first few miles then starts to act up again. I have no idea where to
start looking, please help.
First check for memory codes, if that is a dead end then check fuel pressure and flow, could be a faulty pressure regulator, check for vacuum leaks, intake gaskets are known failures on this engine. When did you have the injectors cleaned? Clean injectors are critical on this spyder injection system. HTH
I just put new injectors in it. How do I check for vacuum and intake leaks, and for memory codes.
Intake leaks can be checked by blocking off the PCV valve and PCV fresh air intake ports then starting the engine and check too see if the crankcase develops a vacuum, if it does then there is an intake leak. A scan tool is the best way to check for memory codes on the old OBD 1 system, but if your watchful enough you can do it with a paper clip and use the flash out method.
Thank you, I'll try that out.
Did it run properly after you put the new injectors in? What was the reason for new injectors?
It was running fine. I put new injectors, distributor cap, coil, plugs, plug wires, and 1 inch riser. I just found a vacuum line that goes to the throttle body that has a crack in it. could that be the problem? I'll replace it, just waiting on the parts store to open.
Unmetered vacuum leak will cause a lean condition that the ECM cannot over come so it can cause a running problem, if it is your problem it is hard to say.
It's not the vacuum line. The store I was at didn't have the PCV valve but there is one in the next town over. I was going there today anyways so I'll pick it up and try it out tomorrow.
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