CPI trouble

My 93 blazer has a bad miss. Everything checks out. Is it possible the fuel injection system(vortec) is the problem, can i switch it to TBI.

My 93 blazer has a bad miss. Everything checks out. Is it possible the fuel injection system(vortec) is the problem, can i switch it to TBI.

Why switch to an injection system that will give you less power?

Have you checked fuel pressure? Have you pulled the upper plenum and checked for washing?

To change to tbi you would have to replace the ECM, harness, lower intake, upper intake, injection system, fuel lines, fuel pump, etc..etc... and then after all that time and expense you would be down about 20 hp

Fuel pressure is perfect. Compression is great, 150 all the way around. Was working on it today. The problem seem to be in #5 cylinder. Checked the Pop-it valve to that cylinder, it is spraying. Replaced the plug and wire(even though they are new). Still no change in the engine when i pull the plug wire off. Is there any thing in there that would stop the fuel from going to #5 cylinder. There is no smell of gas coming from it when the plug is out. Checked for a leak in the intake, no luck there. It has me totally lost. Had 3 people look at it today, still no answers.

Well, if #5 isn't firing then you either have a leak in the poppet hose itself, or something is up with your cap/rotor and it's not sending spark down.

It has been a long day. The plug is gettin the spark, traced it from distribitor to plug. Even pulled the plug and tested it. cap/rotor is new. This has to be fuel, and only starting when the poppet is down in the center head. Could be an obstruction in the line. When the poppet valve is out of the center head it does spray. There is some wash in the center head, but it is a 93 with 240,000. Not enough to make puddles. I should have mentioned this before, but it is heating the exhaust so bad that the mufflers burn out in a month. Totally stumped.

leaking cpi and nut kit can cause this. I would pull the plenum cover and check for washing.

leaking cpi and nut kit can cause this. I would pull the plenum cover and check for washing.

No washing, and the poppet is spraying. Will know for sure Friday, i have a centerhead with cpi on its way.:banghead:

No washing, and the poppet is spraying. Will know for sure Friday, i have a centerhead with cpi on its way.:banghead:

There is no washing and clean spots in the upper plenum at all?

Have you checked the ignition module in the dist?

There was no washing in the center head, and the distributer was replaced along with the module. This has me totally puzzled. I am in the middle of replacing the whole intake, sensors, CPI. That should get it.

Hi Gang, 'jes passin' through.
93glazerhappy, is #5 poppet spraying all the time the keyswitch is on and engine off?

No, the poppet's were dry.

Thanks for all the help Everybody. Problem solved.

The Intake was leaking, I think. I replaced head gaskets and intake manifold. The only thing i could find was the intake gasket was bad at #5. I did try spraying it to check for leaks but the hole was on the bottom under the intake manifold.

Must have been it because it is working fine now.

Appreciate it every body.