Intermitten miss

[Darrell J]

took the ignition control module to have it tested, they tested it 10 times and it's good.
I put some HEET in it just incase it was water in the gas.

put it all back together and started it up.

it still runs rough.

gonna try to check the MAP sensor now and the EGR valve and hoses again.

no codes are showing up now.

[Darrell J]

I did disconnect the Pick up coil wires and tested from the plug end on it.
On the OHM meter, when you test the meter by directly touching the red and black wire the needle zooms across the screen to 0.
Here is a picture of the meter with "open"


Here is a picture of the meter with the 'closed' and this is the same reading I get when I connect to the two wires for the ignition pickup.


When I connect them to the wires the needle does the same thing.

so that's bad? or good?

[Darrell J]

A recap of what is.

The ignition control module tested good.
The pick up coil tested good (from best I can tell, see above)
The EGR valve was bad, would not hold vacuum, so there is now a new one. The vacuum line is good. (tested to hold vacuum)
New roto cap, roto button, spark plugs, plug wires.
Can of HEET applied to the gasoline to eliminate any water in the line that may be causing this.
I will disconnect the EST wire and check/set timing tomorrow, then connect wire back and run.

There are no engine codes showing now.

Will report tomorrow and see what else I can do.

[NEUMANNZZ]

soo your pickup coil is shorted ie bad.

[Darrell J]

Ah HA! Thank you for the interpretation of my work! I didn't know and now I do! Thank you very much! Whaa hoo, I'm stoked! That HAS to be the problem!

THank you very much! I'll pick one up first thing in the morning and stuff it on. I'll let you know how it goes!

I'm running out of things to test so it's got to be it!

Darrell

[supjim12]

I hate to be the bearer of bad news but I was reading and it sounds like your ignition controll module. I had mine tested and it passed but just took a hunch and replaced it now my truck runs great. All I am saying is parts can test good but still be bad.

[Darrell J]

If the new pickup coil doesn't do it, I'll get that part next I suppose.

Good information to have! thanks!

[supjim12]

Originally Posted by Darrell J

If the new pickup coil doesn't do it, I'll get that part next I suppose.

Good information to have! thanks!

I know how that feels though pissed me off cause I had it tested a bunch of times and replaced a bunch of other **** just for it to be that. But live and learn.

[Darrell J]

Went and got a new pickup coil, tested it the same way I tested the old one and got the same results. I don't think the new one was bad or the old one for that matter. Since I had the new one I put it on.

I put the pickup coil on and then put it all back together, timed it, and fired it up.

It idles very smooth at 500rpms. :)

It runs great for about 10 min. Then it starts missing and running rough, whent the engine is up to temp and running down the road.

supjim12, I suspect you are going to be right. Next stop ignition control module. Siiggggghhhhhhhhh. Out of work time today, will have to tackle it tomorrow.

[NEUMANNZZ]

I think your meter is bad.
so it runs bad when it warms up. could be ignition module or cts sensor(coolant temp sensor). cts sensor located next to thermostat housing.
heres a change to test the meter.
temp ohms
212f 177 ohms
194f 241
176f 332
158f 467
140f 667
122f 973
113f 1188 ohms
104f 1459
95f 1802
86f 2238
77f 2796
68f 3520
59f 4450
50f 5670
41f 7280
32f 9420
23f 12300 ohms
14f 16180
5f 21450
-4f 28680

[Darrell J]

I'll test my meter, can you tell me if the setting is correct on the meter in the pic for testing the CTS?

and how do you get the proper temperature reading?

[NEUMANNZZ]

r x 10 setting

[NEUMANNZZ]

for the temp test it cold. go by how cold it is outside. local weather report will suffice. when engine is fully warm should be around 195f.

[green94]

Originally Posted by NEUMANNZZ

for the temp test it cold. go by how cold it is outside. local weather report will suffice. when engine is fully warm should be around 195f.

NEUMANNZZ--- is his issue strictly electrical or could the TBI have issues? My 94 has 267k on the original motor and I have the same issues as he has. I've replaced the same things, but to no avail. Someone mentioned to me that I should look into rebuilding my TBI--would this be a consideration??

Green94

[NEUMANNZZ]

Originally Posted by green94

NEUMANNZZ--- is his issue strictly electrical or could the TBI have issues? My 94 has 267k on the original motor and I have the same issues as he has. I've replaced the same things, but to no avail. Someone mentioned to me that I should look into rebuilding my TBI--would this be a consideration??

Green94

if fuel pressure is good. check vacuum. if vacuum is low, check compression.

A tbi rebuild replaces gaskets(base gasket included) and screens for the injectors. do the injectors spray a nice cone pattern barely seeable?
distributor drive gear in good shape(not knife-edged)
timing eratic?

[mattkx125]

darrel did u ever figure out the cause of your problem?

[Darrell J]

checked the temp sensor it's fine, checked the volt meter, it's fine.

TBI is spraying good, very good cone pattern, barely visible.

still don't know what it is.

next stop, gonna take the valve covers off and look at the pushrods. I'm guessing one is bent.

[Darrell J]

still don't know what the problem is.

getting someone else to look at it. Will keep updated on results.