S-10 Forum banner
1 - 20 of 27 Posts

·
Registered
Joined
·
133 Posts
Discussion Starter · #1 ·
Hi all I am new hear 1st time posting. I am having starting problems on a 2003 zr2 with 83000 miles on it. I did a search and didn't find what mine is doing.Sometimes when I try to start it( hot or cold in the morning) it just cranks and cranks for 2 or 3 times and finally starts. I have noticed that sometimes when you let off of the key it will fire and start. It's like it won't start in the start position on ignition switch, but when you let off to the run position that's when it will fire and start. Is there a starting circuit to get more juice to the ignition? It acts like it is not getting juice to the distributer until you let off the key. It runs fine after you get it started, until it cools off and then the problem starts all over. Just changed the fuel pump and filter. Haven't done cap,wires or plugs yet. Any ideas what to look for? I just bought this truck about 2 months ago. I traded a 98 zr2 for it, The 98 never failed to start. It was running on the first turn of starter, as soon as you hit the key. Sorry for the long post. Any help,or ideas would be greatly appreciated. Thanks Eric
 

·
405AWDHP
Joined
·
2,327 Posts
Issue is known as extended crank time.

When an engine cranks for a long time before it starts, either spark or fuel is missing or weak and each has its own reasons. Most of the time, the air / fuel mixture has been disturbed and there is too much air or not enough fuel. Many sensors report to the computer, who then takes that input and controls fuel or air delivery, is suspect when diagnosing long cranking times. A bad coolant sensor, a bad throttle position sensor (TPS), a bad fuel pump or a plugged fuel filter can all cause a lean condition causing long cranking times. Sometimes the spark is delivered late, weak or not at all. A weak coil or bad coil wire, a bad pick up coil or crank sensor or a bad rotor can all cause a change in the spark.

If you know when it will not immediately start, try spraying carb cleaner or starting fluid in the duct that carries air to the air filter. If by adding "fuel" the engine always starts faster and cranks over less, then you will know it’s a fuel delivery problem

Another easy thing that you can do is simply change the spark plugs. As always, if the problem changes, for the better or the worse, you are on the right track. If you do not see a decrease in the cranking time then most likely it is a fuel delivery problem.

You might also use a fuel additive each of the next 2-4 times you fill up. Look for something that claims to remove intake valve deposits. These deposits act like a sponge and soak up the fuel as it is sprayed on the back of the intake valve. So if the engine is warm or cold, this sponge has to be saturated and begin to drip before the engine will start and extended cranking is one of the classic symptoms. By trying the fuel additive and thinking of this as a diagnostic procedure, if your problem gets better, continue to use the fuel additive. No change, stop using the additive. additive.

If it is a "warm restart extended cranking", almost always it is low fuel pressure caused by a plugged fuel filter or a bad fuel pump.
 

·
Registered
Joined
·
133 Posts
Discussion Starter · #3 ·
Almost allways after it is warmed up and you shut it off, it will start right back up on first turn. if it sits for 15 mins.or more it is hard to start. I am going to change plugs this weekend. Will let you know what happens. Thanks again. Eric
 

·
Registered
Joined
·
133 Posts
Discussion Starter · #4 ·
Ok, changed the plugs thursday. when i went to work friday it still cranked for a long time before it started. I went out on the interstate and thought I would blow the cobs out of it. The truck went up to 75 mph with no problem and then it was like someone threw out the anchor and it would not run any faster. The check engine soon light came on and blinked on and off all the way to work. Shut it off and restarted it and light was out. This thing is starting to drive me nuts. Before I changed the pump and filter I had the pressure checked and they scanned the system and it didn't show any codes. Anybody have any ideas what could be wrong??? Could it be distributer cap and wires and rotar, or maybe iginition module?:dunno: Any help would be appreciated!!!
 

·
Registered
Joined
·
133 Posts
Discussion Starter · #6 ·
Ok here is the history of my truck. Just bought it 2 months ago. 2003 ZR2, 83000 miles, all stock except for K&N filter kit and performance muffler. As I stated before it cranks hard before starting, hot or cold. Had pressure checked, was 50lbs and dropped to 0 when shut off. Replaced pump and filter and pressure is 60+ when cranking, 50 when shut off and climbed to around 60 after sitting for 20 mins. Replaced plugs thursday. went for road test on interstate, got to 75 mph and thats all it would do. Check engine light came on, had codes read, codes were: P0101- MAF and P300-missfire random cylinders. Havn't changed cap, rotor or wires yet. Should I start there? It's got to be something simple, it runs good after it starts. Thanks for listening. Eric
 

·
Registered
Joined
·
990 Posts

·
Registered
Joined
·
133 Posts
Discussion Starter · #9 ·
Can you use carb cleaner to clean MAF? Or will it ruin the MAF? Also would the MAF make it hard to start? The only time I got the codes was at WOT. I normally don't drive that fast but it was a road test to see if it ran any better. It seems to run better since I changed the plugs, but it is still hard to start. No other codes but the P0300 and P0101.
 

·
Registered
Joined
·
990 Posts
Can you use carb cleaner to clean MAF? Or will it ruin the MAF? Also would the MAF make it hard to start? The only time I got the codes was at WOT. I normally don't drive that fast but it was a road test to see if it ran any better. It seems to run better since I changed the plugs, but it is still hard to start. No other codes but the P0300 and P0101.
I do, never had a problem

and yes, it could make it hard to start
 

·
Registered
Joined
·
133 Posts
Discussion Starter · #11 ·
Still trying to figure this one out. Cleaned the MAF still no change. I am going to change cap and rotor this weekend with AC Delco parts. I have read a lot of posts about long cranking before starting, it takes 2 or 3 times before starting and etc. etc. I don't know why the truck will crank and crank and when you let off the key to the run position it will start to fire and stumble for a few seconds and then run fine. Then if you shut it off and restart it will start on 1st turn every time. It will run fine after it starts, and I am getting 17.5 to 18.5 mpg ( city and highway). Could this be injectors leaking down? How can you check them without a tear down to inspect them? I have worked cars and trucks for years, but this one has me stumped. Any ideas of what else I should be looking for would be GREATLY appreciated. Thanks Eric
 

·
Registered
Joined
·
7 Posts
I have the exact same problem on my 99 4.3l s10 with 118xxx miles on it. And i also have the k&N filter, i read on here somewhere that the oil based filters get the MAF all gummed up. Im changing the spark plugs, wires and cap and rotor, fuel filter, and clean the MAF today ill let you know if i get a change in cranking times. Let me know if you figure it out.
 

·
Registered
Joined
·
54 Posts
You could possibly have a bad maf, I would start with the basics, plug wires, cap, rotor, fuel filter.. The K&N air filter oil has been known to damage Maf sensors if too much was applied to the element.
 

·
Registered
Joined
·
133 Posts
Discussion Starter · #14 ·
How can you test to see if the MAF is good or bad?? Be fore I just go out and spend $70 or $80 on a new MAF.
 

·
All about the bolt on's
Joined
·
69 Posts
before you buy a maf try cycling the key switch 3 or 4 times slowly from the off to the on position. This will pressure up the fuel rail if the fuel pump is getting old or checkvalve is bad it taking longer crank times to start. If you have a fuel gauge its even better to see whats going on
 

·
Registered
Joined
·
133 Posts
Discussion Starter · #16 ·
Read the 1st part of my post roughneck 427. it's a 4.3, new pump and filter, also new plugs. Tried the on and off before starting, still no change. Ordered new cap and rotor. Going to replace this weekend. Then see what happens.
 

·
All about the bolt on's
Joined
·
69 Posts
Read the 1st part of my post roughneck 427. it's a 4.3, new pump and filter, also new plugs. Tried the on and off before starting, still no change. Ordered new cap and rotor. Going to replace this weekend. Then see what happens.
Sorry failed to read that. You can unplug maf and will default to OL and see if starts better. But get that code checked out if you have acres to scanner just look at maf hz data to see if it's defective. Also I'd have to look at schematic the oil psi switch on certain years shut off the fuel pump. If it's lazy that could be a issue
 

·
Registered
Joined
·
133 Posts
Discussion Starter · #19 ·
Ok here we go again. Replaced the cap and rotor. Cap had green corrosion on all terminals and rotor had a hole burned in center metal tab. I thought , this is what was wrong with it all along. I put it back together and went to start it, but it still started hard,(cranks and cranks before starting). When you shut it off after it has been running for a while, it will start right back up as soon as you touch the key. If you let it set for 10 or 15 min it will crank and crank again before starting. Has anyone ever really solved starting problems like this. I have read alot of posts on here and they all have good things to try, BUT I have not read where the problem was solved. The posts just seam to stop with the problem not being solved. Any ideas what else to look for? Next thing to check, fuel system? How do you check the injectors and FPR? Sorry for the long post, but this thing has me stumped. Eric
 

·
Registered
Joined
·
990 Posts
check fuel pressure
 
1 - 20 of 27 Posts
Top