little help.... please

[Toomanycars]

Ok my wife bought a 1992 buick roadmaster .. it has the tbi 350 ..

The car ran ok when we bought it about a month ago.. it had a little hesitation when the motor was cold but it seemed to go away once it warmed up.. within the last week the car has gone down hill fast .. It cranks over for a good 3 to 5 mins when cold before starting .. sometimes when it dose start it dies right away .. when it stays running it surges idling up and down .. If you rev the piss out of it, it will come out of it and idle fine for a few min and start it all agian ... when you actualy drive it it likes to stutter and fall on its face ... now there are no codes or ses lights..

So far I have taken the throttle body off and cleaned it from top to bottom. I replaced the map, tps,egr, the idle control thing put two new injectors in it replaced the fuel filter . Put new plugs wires cap and rotor on it. And I took off the catalytic converter thinking it could be clogged...

Everything I have tried has helped for a little bit then it gose back to crap ..

Any thoughts or opinions

[MR.hp]

Make sure you have between 9 and 15 psi to the injectors on a tbi engine.
Check your grounds and make sure they are good and clean, The one by the T-stat is the worst offender.

Check the CTS sensor and make sure the temp on the scan tool is the same as the temp in the dash if you have a guage. Did I say scan tool?, You might need one to diag this plus there is a chance that you may have a bad pcm quad driver.

Hope this helps.

[Guest]

Dirty fuel sock in fuel tank?

[Toomanycars]

thanks HP .. I have a friend with a scan tool im going to try ... i will clean all the connections ...

Quicker <><><> I was thinking about dropping the tank and installing a new pump and fuel sock.. i was gonna blow some cleaner threw the fuel lines as well ..

We just had our son on thurs June 24th and this is our only 4 door vehicle.. so im trying to get this dam baby chariot going and reliable ....

[Tradbuilt]

Is this a plastic upper plenum Buick? I know the 98 3800 my kid has is. The plastic fails around the EGR port which allows the water to flow into the plenum and then into the engine cylinders. His did it between here and Chicago on his way home and dumped coolant into the cylinders. I don't know if that relates to a 350 or not.

A good place for Buick info:
http://www.gmforum.com

Could possibly be a bad Crankshaft Position Sensor or even a bad PCM. Scan it while cranking and look for a crank signal. They had lots of problems with those.

[Tradbuilt]

Have you looked for the simple stuff like vacuum leak somewhere? That will cause a lean mixture causing the engine to crank excessively before start up.

[Guest]

Is this a plastic upper plenum Buick? I know the 98 3800 my kid has is. The plastic fails around the EGR port which allows the water to flow into the plenum and then into the engine cylinders. His did it between here and Chicago on his way home and dumped coolant into the cylinders. I don't know if that relates to a 350 or not.

A good place for Buick info:
http://www.gmforum.com

Could possibly be a bad Crankshaft Position Sensor or even a bad PCM. Scan it while cranking and look for a crank signal. They had lots of problems with those.

There was actually a class action lawsuit on it a while back that paid for replacement. I think it's expired now though.