Stuttering problems!! - Page 2

BlazerLT · #16 11-30-2004, 10:13 PM

That's fine , you are lucky.

Most people that put a restrictor plate will experience the check engine light coming on until they drill the holes out enough.

Just for an experiment, remove the plate, reset the computer and try it without it.

busa_4 · #17 12-01-2004, 08:26 AM

the computer doesnt throw a code because it doesnt think anything is wrong with the egr system. when the computer activates the egr valve fuel and timing are changed to compensate for the egr gasses going into the engine. you blocked off the egr. the computer doesnt know it. it thinks egr gasses are flowing through. it changes fuel and timing not knowing there is no egr gasses in the engine. hence your stumble/stutter. you have to remember the ecm is dumb is is reading off of a program. there is nothing in there telling it that you blocked of the egr.

Mikado14 · #18 12-01-2004, 10:40 AM

Then if what you are saying is true, the O2 sensor will not change fuel other than by what the LEGR is doing, the knock sensor will only change timing based upon the LEGR only, the MAP sensor only measures the barometric pressure to check the operation of the LEGR, etc, etc.

If what you are saying is true, then how did the poster drive 20,000 miles without a problem? I haven't seen anyone explain that yet. Is the computer so slow that it took that long?

Back before there were any O2 sensors, MAP, TPS, fuel injection as stock and all the other sensors, you had PCV's, air pumps to inject cold air to burn off unspent HC's, heat riser valves and vacuum operated EGR's. This would have been the late 60's to early 70's. And when those EGR's would plug up with carbon, and they did quite frequently, standard operating procedure was to clean them, and plug off the vacuum line. They still ran and performed fine.

The LEGR is not unique in sending a signal to the ECM. Ford has been doing it for years with their EEC-IV with a plunger mounted on top of the EGR. They can be plugged off as well and the engine will operate fine. The computer will recieve the signal, the ECM believes it is open, the O2 monitors the exhaust gases and will adjust the fuel delivery based upon the position of the throttle, the vacuum in the manifold, the incoming air temperature etc. The purpose of the EGR system is to reduce the NOx only which is the main culprit in smog.

We see the EGR at times to be a problem but that is due to it not closing properly and creating a vacuum leak or in the case of vacuum operated another vacuum leak if the diaphragm is ruptured. In the case of an EGR being stuck closed, your looking at a failing condition in exhaust gases during an emission testing depending upon the acceptable levels being looked for.

BluBlazer · #19 12-08-2004, 02:01 AM

Ok. I have checked all my connections, put the EGR back in service by removing the block off plate, pulled the computer and check those connections. I drove it about 200 miles without a problem and then tonight on my way home from work it was doing it again. No codes were stored in the computer. I am wondering if the computer itself is going bad??? The only thing common with the TPS and the MAP is that they are both supplied with the same 5volt reference from the computer, not the same ground like I previously thought. I am running out of ideas!!!

BluBlazer · #20 12-08-2004, 02:08 AM

One other thing, does anybody know where the ESC bypass connector is on a 93 CPI. I can't seem to find it and I am about to cut the wire to check my timing.

Mikado14 · #21 12-08-2004, 10:54 AM

Quote:

Originally Posted by BluBlazer

One other thing, does anybody know where the ESC bypass connector is on a 93 CPI. I can't seem to find it and I am about to cut the wire to check my timing.

Pull your carpet back under the drivers side up under the dash. It is a small (approximate) 5/16" connector with brown/white tracer. Can't miss it.

gbic1 · #22 12-08-2004, 02:14 PM

Do you have a scanner that allows you to read the volts to the tps? If not you can back probe the connector than slowly sweep the tps slowly while looking for a smooth increase in the voltage. It should start below one volt, I believe usually around .60 volts and go up to around 5 volts give or take. It you find a flat spot then the tp is bad and confusing the ecm.

BluBlazer · #23 12-08-2004, 03:21 PM

I must really be blind because I have looked all under the driver side dash and still can't find it. Is the Brown/wht wire the only wire in the connector?

gbic1 · #24 12-08-2004, 03:57 PM

I thought it was on the passenger side under the heater box at carpet.

Mikado14 · #25 12-09-2004, 10:41 AM

Quote:

Originally Posted by BluBlazer

I must really be blind because I have looked all under the driver side dash and still can't find it. Is the Brown/wht wire the only wire in the connector?

I am sooooooooo sorry BluBlazer. I done got my right and left all discombobulated.

It is the passenger side and it is easy to find. I was thinking passsenger and don't have a clue why I typed driver's. Must have been a bad morning.

BluBlazer · #26 12-09-2004, 01:47 PM

Ok....I think I found my problem..the two wires going to the CPI unit in the intake from the external engine harness must have a break in them. Everytime I touch the wires with the engine running it stumbles and even kills it. Now, I need to find the harness so I can replace it. I would use regular wire, but these wires are teflon coated. The dealer wants $70 dollars for the harness. OUCH!!!!

BlazerLT · #27 12-09-2004, 04:26 PM

Just replace the wire.

You don't have to replace the whole harness.

BluBlazer · #28 12-09-2004, 08:13 PM

The harness that I am speaking of starts at the CPI unit with a connector and goes from the CPI unit through the intake plenum and out to the main engine harness to another connector. There are only two wires in this harness and what makes them special is that they are Teflon insulated so they can stand up to the conditions inside the intake. The total length of the two wires is only about one foot. The trouble that I am having is finding teflon insulated wires. Once I find the wire, I am just going to cut the old wires off of each connector and attach the new wires to them. The dealer wants $70 bucks for the new wires and connectors.

BlazerLT · #29 12-09-2004, 08:18 PM

Yea, that is what I would do.

Or maybe use the shrink tubing on them.

Mikado14 · #30 12-10-2004, 10:20 AM

Quote:

Originally Posted by BluBlazer

The harness that I am speaking of starts at the CPI unit with a connector and goes from the CPI unit through the intake plenum and out to the main engine harness to another connector. There are only two wires in this harness and what makes them special is that they are Teflon insulated so they can stand up to the conditions inside the intake. The total length of the two wires is only about one foot. The trouble that I am having is finding teflon insulated wires. Once I find the wire, I am just going to cut the old wires off of each connector and attach the new wires to them. The dealer wants $70 bucks for the new wires and connectors.

How about looking in a bone yard?

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