93 blazer throttle body surge problems

[ebcjlc]

Here is the history from what I know working on my Father in laws 93 Chevy:

Bought it, it ran good. Blew a head gasket some time later. Replaced it and everything was good for awhile. Later it starting having power problems and wouldn't stay running. Smelt like rotten eggs, his friends all told him to replace the catilitic converter. So, he did along with the O2 sensor. Did not fix it. Then he notice the fuel pump went bad. Replaced it and the filter. still didn't run right. Installed a pressure gauge to see his fuel PSI::: runs about 10 psi. Pluged the fuel return line to see if it holds pressure, it bleed off semi quick. I then replaced the pressure regulator. We now have good fuel flow. It will start and run but doesn't idle right. I n about 20 second intervals it starts to die and then revs back up on its own and about every tenth time or so it will completly die. I checked the IAC with a meter and it has 68 ohms at both A to B and C to D. It is has also had the spark control module in the distributor replaced. Any ideas? I have an Auto Xray to read the system but haven't gone that far yet. 93 Blazer, throttle body 350.

New plugs, wires, cap, and rotor.

[billibong]

Have you checked the nut kit?? I understand that you replaced the regulator, the next thing might be the Nut Kit.
There are several people on the forum that have more experience than I do in this. I'm sure that they will chime in either in support or telling me I'm all screwed up...

[blazes9395]

Get a TPS reading. The reading should be about .8 volts, and ramp up to 5 volts as you open the throttle. To high TPS value will cause all kinds of trouble, the computer will be all over the place trying to find idle.

[BlazerLT]

Ok, is this a full size?

Sounds like you need to check the following:

PCV Valve,,,,replace it.
Fuel Filter...replace it
Vacuum lines, check them all for cracks and proper connections, heack replace them all with the same size windshield washer fluid tubing, it is cheaper and is the same tubing.

Check timing with the timing wire removed from the PCM, remove the brown/beige wire, time to zero, reconnect the wire.

[ebcjlc]

The fuel filter has been replaced. along with the vacuum lines. I have not checked the throttle postion sensor yet. What is "Nut Kit"?

[BlazerLT]

Hold on, is this a full size truck?

And you have replaced the parts I mentioned above and have you ever checked the engine timing?

[ebcjlc]

You know it is funny you mention that. I wanted to check the timing chain specifically (to see if it skipped a tooth but havn't) Did put a timing light on it and things look good but I had a dodge do something simular, but not identical and it turned out to be a bad chain. My father in law doesn't think that to be the case.

[BlazerLT]

Remember you have to unconnect the timing wire from the PCM when timing the engine.

Also, can you re-read the thread and answer the questions I posed?