170k 1994 5.7L Suburban. It has been running perfect but slightly rough lately. It was fine coming home from work today and had it parked for approx 20 min. . I jumped back in and tried to start it and all I got was a very small quick misfire and nothing else. I tried pumping the pedal but no difference when turning over. I sprayed starting fluid in the throtle body and presto, it started and stayed running. It is a bit rough and needs a tune but could that be the sarting problem? Is it as simple as a new cap, rotor, wires & plugs??

Any thoughts would be appreciated. I am obviously going to do the tune but was just curious if there maybe something else I may need to look at.

Ron

 

Here is the deal.....When it's cold, like 1st thing this morning, It starts and runs fine. When it's warmed up, it won't start unless I give it a shot of starting fluid and then it runs fine.

fuel pumps either work or they don't...right?

anything guys??????

 

Could be the fuel pump (like you said). I've had some work intermittently on occasion and then fail completely. Is the fuel pump stock? Also, this is a carburetor engine? Sorry, not familiar with Subs earlier than 99.

 

It's a throttle body injected set up and I think maybe a mechanical fuel pump. Not sure about the pump.. I haven't looked it up yet. I have seen electric pumps go intermittent.

 

I did my tune up today and just for the hell of it, I had a spark tester between the coil and the Cap just to see if there was a delay in spark when turning it over. Well it sparked and started fine BUT it just stopped after a min. or so. NO spark what so ever now. I tested the ign. fuse and there is constant power when turning it over. What do I check now? I tested the black and gray spouts on the coil but there was no power there if that means anything. I am at a loss in trouble shooting this. All ignition parts other than the cap rotor wires and plugs are original. Remeber, I have 172k on this truck.

Any help please!!!!!!!!!!

 

I double checked and there is power going into the coil and comming out the other spout that feeds to the distributor when in the run position.

 

problem solved! Replacing my igniton module, which tested ok by Autozone, did the trick! Started right up. Just would of liked to see some input from this forum. Very disapointed.

 

Good that you found it! Again, like a fuel pump the intermittent thing was probably going good when they tested it. Well, don't be disappointed dude ... it's better that if no one knows what's wrong to not offer at all sometimes. Can lead to confusion. Tough to guesstimate through cyberspace, ya know? Hang loose bro!

 

300,000+ '94 5.7, no problems until recently. Starts every day for a week, then Dead! Suggestion has been to change steering column, easier than checking faulty wires caused by tilt steering. Other ideas before doing this.

 

You might want to start this as a new thread.