89 Olds V-6 Hard to start.

My son has an 89 Olds Delta 88 3.8L V6 with 110K miles. It slowly (over months?) began getting hard to start. Hot or cold engine or weather. Can only start it now with a squirt of starting fluid in the air filter. The MAF sensor has to be UNPLUGBED to start at all.

When it does start it idles OK but lacks power at low and high speeds and wants to "pull back" or stutter?

There are no error codes from the slef-diagnostic lights.

Have replaced the O2 sensor, MAF sensor, fuel filter, air filter, plugs, and wiresl Have checked the vacuum, fuel pump pressure, and throttle positioning sensor.

I've heard of a crank sensor but can't seem to locate it if it has one.

The throttle body was carboned up, cleaning it did nothing.

Am at a loss on this one. Any help????

Reply to
Lurker
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Coolant temperature sensor (or intake air temp sensor, if it has one - could be part of the MAF) could be bad - these can be checked by either looking at readings on a scan tool or measuring resistance and comparing with a resistance vs. temperature table.

Won't be the crank sensor if it starts with starting fluid or with the MAF unplugged..

Reply to
Robert Hancock

Did you check the fuel filter? If it starts with starting fluid, you ain't getting enough fuel. Possibly a fuel pressure regulator?

Reply to
clevere

Didn't check the coolant temp or intake air sensor. It has an intake air sensor in the air filter box - it's a little hard to get to.

Any info on where I can get a resistance to temperature conversion chart??? I have a meter.....

Thanks for the help so far...

Reply to
Lurker

There's one here:

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Reply to
Robert Hancock

positioning

Reply to
Lurker

Checked the Intake Air Temperature Sensor and it was BAD (the air outside was NOT 220 DegF - more like 19 DegF). Plugged in a 12000 ohm reistor in the plug and the car started and ran relatively well. Plugged in the MAF sensor and it started (on first crank over) and ran relatively well. Located the Neihoff replacement at auto parts store. Will replace tomorrow.

If anyone knows how to clean the intake manifold of carbon it would be great too. Some spray available?

Thanks to all in this great group (and especially Robert Hancock). Happy Hiolidays !!!

positioning

Reply to
Lurker

Cleaning the intake manifold usually requires removing it but using a good quality injector cleaner should help to clean it. Look for Sea Foam brand or Techron (a Chevron brand) injector cleaners. Both of these are used by race car enthusiasts and garage mechanics. Things like STP and Gumout work but aren't as good.

Reply to
Rich B

The MAF sensor was unplugged, but the computer didn't store a code for it?

That's weird.

Hopefully things are going ok.....

Reply to
Clem

Reply to
Lurker

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