Help with poor running TY

T

tphilpot

New member
HI Folks, I am in serious need of help, I have a TY that is basically stock. I have spent a fortune trying to get it to run right. I have used Datamaster and it isn't showing anything that you can't feel. Boost is fine (up to 14.7), Spark retrard is OK (3.5). There is a code 42.

Here are the symptoms: Good mid range pull, loses grunt at 4,000 rpms even with full boost. Kind of sputters a bit. Also when at about 1,700 rpms under a small load it does the same sort of sputter thing. Yesterday it puffed white spoke on start up.

Here is what I have done:

- New distributor, new cap, new plugs (42's), new wires.
- vac lines all new
- injectors cleaned
- heads rebuilt
- all new top end gaskets
- new radiator
- new tranny cooler
- new cat back exhaust (done by RPM)

The timing is right, the fuel pressure is 45lbs at idle. As mentioned datamaster doesn't show anything sinister except the code 42.

The shop that has done the work is now at thier wits end (as am I).

Any ideas? Bad Cat? Bad ECU?

Thanks for any help.
 
sytyguy

sytyguy

Moderated User
Re: Help with poor running TY

Upload a DM run of the problem area.

Have you checked the plugs since installing?
What's the age/mileage on the cat converter?
The boost reading....is this the stock gauge, DM, or an aftermarket gauge?
If you go WOT from a standstill, does it feel strong and make full boost up until 4k rpms and then fall flat?
How about in 3rd gear at highway speeds? If you stomp it (rpms should be around 3k) does it make full boost and pull strong until it gets into the 4k rpm area?
Stock chip?
Healthy fuel pump?
 
T

tphilpot

New member
Re: Help with poor running TY

Thanks for the reply. Not sure how to upload the file. Plugs are brand new. I believe the Cat to be stock, 123k miles. I am using the DM for the boost reading. It never really feels fast. Just alot worse at 4k rpms. At highway speeds it has nothing! Floor it at 60mph and is downshifts, boosts up and just doesn't really go anywhere. Dunno about the fuel pump. It makes 45lbs at idle.
 
sytyguy

sytyguy

Moderated User
Re: Help with poor running TY

Forgot the SyTySolo uploader is for members only. My bad.

Getting a bit more knock retard than you initially said.....getting nearly 7 deg in some areas. I'm with Dave....any odd ignition quirks you see (tach flutter, etc...)? Code 42 might lend itself to a failing Ign Module.
 
T

tphilpot

New member
Re: Help with poor running TY

sytyguy said:
Forgot the SyTySolo uploader is for members only. My bad.

Getting a bit more knock retard than you initially said.....getting nearly 7 deg in some areas. I'm with Dave....any odd ignition quirks you see (tach flutter, etc...)? Code 42 might lend itself to a failing Ign Module.
Click to expand...

Yes, the tach does jump a bit. Any way to test the ignition module?
 
dgoodhue

dgoodhue

BuSTeD 4.3
Re: Help with poor running TY

Tach jumping usually indicates ignition problems. Make sure non of your wires are hitting the exhuast. I have seen corrosion on the 2 wire connector from the dist to coil cause flutter. The coil could cause he problem as well.
 
Icarus-54

Icarus-54

Donating Old Member
Re: Help with poor running TY

Is the coil MSD?I've had 2 (both new) that were no good.That will also make the tach go crazy.
 
Berra

Berra

New member
Re: Help with poor running TY

I had the same problem.. First I replaced wires,plugs, cap, rotor and checked for vac. leaks and the truck was still running like crap. Then a friend of mine said that I prolly had a bad ignition module. I replaced it, a 5 minutes job, and now the truck is running great again. I had NO codes indicating a bad module......
 
TWINTURBOV8

TWINTURBOV8

Member
Re: Help with poor running TY

This might be a stupid question but where is that I don't know these trucks that well I just bought my truck or is it in my manual. Thanks for all the help.
 
powercat6

powercat6

Active member
Re: Help with poor running TY

TWINTURBOV8 said:
This might be a stupid question but where is that I don't know these trucks that well I just bought my truck or is it in my manual. Thanks for all the help.
Click to expand...

If you're asking about the ignition module; it's underneath the distributor cap.
 
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