93 chevy 350 Is it possible to

Is it possible to have a spark at the plug while out of the engine but once reinstalled into the engine the plug wont fire? Like not strong enough to sustain a spark under compression. Because I am at a loss with my van that is only used on weekends. 93 with 60,000 miles on it will not start.

new cap new rotor new plugs new egr

Reply to
flogg55
Loading thread data ...

Is it getting fuel? Pop the air cleaner off and watch the injectors while cranking. They should be spraying fuel while cranking. And to answer your question, yes it is possible to get spark while out of the engine but not once it's installed. What color is the spark when out of the van?

Doc

Reply to
"Doc"

Hi Doc Yes I can see gas being sprayed in carb. As for the color of spark I am not sure kinda a light blue I guess. Is there a module that can be changed?

Reply to
flogg55

If the spark is blue you're in good shape. Try this, pop off the oil fill cap and have someone crank the engine while you watch the rocker arms for movement (testing to see if timing chain is shot).

To get her to fire you need spark which you have, air and fuel which you have and timing (both valve and spark). Dies it "try" to turn over but not quite get there or is there not even a cough as you're cranking.

Did you put the plug wires back in the correct order?

Doc

Reply to
"Doc"

As Doc said about the timing chain, but also pull all the plugs and take the distributor cap off and set aside. Notice where the rotor is pointing, rotate the motor by hand at the crank with a breaker bar if needed. Then rotate the other direction and see if there is a big lag before the rotor turns with the motor. I've seen the chain so loose that the valve timing will be so far off it won't fire. As well the chain could have jumped on the sprockets and be way out of time.

Brian

Reply to
NoSpam

The only time it seems like it might start is when I have the pedal clear to the floor. There is smoke smelly fumes. The van only has 60,000miles would it be possible the timing chain be loose?

Reply to
flogg55

Anything is possible. It's not very probable, but it's possible. Based on your above description it could be too much fuel in the mixture, weak spark or a valve timing problem.

Here's a thought. Yank one of the injector harnesses and see if she'll start with just one injector running.

You could be a crazy mo-fo and disconnect both injector harnesses and see if it'll start with you drizzling a little fuel down there (a LITTLE fuel). You could even use starting fluid, sparingly to see if it'll turn over without the injectors pumping the fuel out. Either of these would point to way too much gas being dumped into the TB during cranking, usually a sign of a shot fuel pressure regulator.

Doc

Reply to
"Doc"

Is it true that there might be a nylon gear on the timing chain? If so why? Wouldn't this wear out faster? If I had this problem this sounds like a costly repair right?

Reply to
flogg55

A lot of American made cars including Chevy used an aluminum camshaft gear that had nylon teeth on the gear so that the noise was low. And yes they do wear faster and could be your problem. I don't know how ever if in 1993 they were style nylon. Some of the others on this group might know. When replacing it's pretty standard practice to use an all steel gear.

Brian

Reply to
NoSpam

Costly, no. On a van it's a massive PITA.

You need to remove the waterpump and balancer/crank pulley to get the timing cover off. Once the cover's off it's a piece of cake. On a truck with lots of working space it takes me maybe 3 hours with a few beer brakes. On a van I'd plan for all day.

Doc

Reply to
"Doc"

cover off. Once the cover's off ...a few beer brakes ...

Last time I swapped a timing chain, I dropped the pan in order to get the timing cover off.

John Goodlad Hermosa Beach, CA

Reply to
John Goodlad

I can usually get the cover off but when I put it back on I trim the two corners that go by the oil pan and use silicon to prevent leaks.

OT: I see that your from Hermosa Beach. My son is the manager of the Union Bank on Pacific Coast Hwy at Hermosa Beach. I live in Ohio and visit Hermosa Beach (and my son) a few times a year. It's beautiful out there.

Brian

Reply to
NoSpam

Last time I swapped a timing chain.....

Please let me know when you're again on the "left" coast as I'd enjoy extending a "welcome" on your next visit!

John Goodlad Hermosa Beach, CA

Reply to
John Goodlad

The fate of my 1972 Chevelle.....

~KJ/TLMG

Reply to
KJ

I too have a had a couple of Pontiac's GTO's, and Grand Prix's that fell down due to this during the 70's.

Brian

Reply to
NoSpam

I replaced with an all-steel chain but now it needs a valve job - as mine failed going about 70....MPH....

~KJ/TLMG

Reply to
KJ

The 1970 Pontiac 455 must have been a clearance motor as I remember that chain went at about 40 mph, but I was in low gear with the Turbo 400 transmission. ;-0 Valves didn't bend, I put a new chain and both gears in and away we go.

Reply to
el Diablo

Ok I have ruled out timing chain problems. A friend of mine let me use a new ignition coil and a ignition module I tried both separately. When I tried the ignition module the engine started! The engine was running but seemed to be running rich. I figured because it was loaded up after repeated tries of starting. So I started to back up and it died once again and never started back up. Geez now what? I had taken the original mod to Advance Auto and they said the original was good. My friends mod that I tried started the engine up after 1 week of unsuccessful attempts. Did I just ruin my friends mod? I hope not. Now what about the coil under the rotor. Could that be my problem?

Reply to
flogg55

Sounds like when you moved the pick up wires:

The pickup coil worked momentarily, then got warm and broke down again. I would replace the pickup coil in the distributor before doing anything else.

Refinish King

Reply to
Refinish King

Well gang I have solved my problem and I will share it. Since most of my original thread is gone here is my story in a nutshell. My van is a 1993 only used on weekends an vacations. It had 60,000miles and I had never had a problem with it. One day we got in and it would not start up. The following week was a nightmare of trial and error. I went from replacing every ignition part I could to contemplating replacing timing chain and sprocket. What was happening as I said before after I put new plugs, rotor,and cap on the engine and it started. Well that was short lived after about a minute it would start to chug and blow smoke then die. It would not start again. The next day I tried a brand new ignition module and it started again only for a minute or two bellowing smoke and smells of gas. I then pulled a couple of plugs and noticed they were wet. The whole time I am checking things I had been getting spark but now the plugs were fouled and would not spark. I had been getting all kinds of advise and looked into each one. It was getting vary frustrating but I did appreciated all the advise I had been getting. Pretty much everybody has said the same thing "If you have gas-fire-air your engine should run." I guess that used to be true till the inception of the computer. This computer has thrown a monkey wrench into logical thinking. Getting back to my problem solving I bought new plug wires and plugs to replace the fouled plugs and old wires. I tried that and it started once again and seemed to run a little longer but I could tell this was not the answer either and I shut it off the engine and came back here to this group looking for answers again. I was reading a thread were a guy was having trouble with his Silverado running to rich and stalling alot. Somebody had mention if he checked his coolant temp sensor. A recommendation was to disconnect the sensor and try it. Well I am game what the heck I have tried everything else so I disconnected the coolant temp sensor and started the

350 up. WOW! started up like nothing ever happened my mouth dropped and I think my heart skipped a beat!!! Geezzz a $8.50 part cause so much grief. Replaced the part and runs like a champ.Ah I can sleep again.... I hope this will help somebody that might have the same problem. I guess my coolant sensor was shorted so badly that it was dumping so much fuel that it could not start up correctly. Thanks to everybody who helped me I hope this helps somebody.

Mike

"el Diablo" wrote in message news: snipped-for-privacy@giganews.com...

Reply to
flogg55

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.