really wierd engine start problems

[Alibi]

1990 olds 88 royale brougham
(Alibi's brother)
Okay, scenario--my Olds has 109K miles, the 3800 V6, and has had very few problems. I went on a trip and let a brother use it. He was driving on a city road at night and found a gigantic pothole that he couldn't miss. Afterwards the car didn't stall or anything. He pulled into McDonald's and turned it off. After attempting to start it back up, he got it jumped. That worked fine. He got it back home. The next day it wouldn't start again. Jumping does NOT work this time. It kept cranking but wouldn't turn over.
*It cranks and doesn't turn over

So far my brothers and I have been trying to narrow down what broke/rattled loose.
--Sparkplugs / wires are new and were properly connected
--ignition module/coil pack replaced(salvage OK)(started once, took home, turned off then on and still *)
--alternator replaced(salvage OK)(started, drove for 20 miles, came back, turned off. still *)
--battery checked and recharged
Any other suggestions before I resort to the mechanic's knowledge?$$?

[diesel1962]

Hello.If I were you I would buy a fuel pump pressure gauge.They do not cost much,20-30 bucks.Maby after hitting huge pothole,The fuel pump may have gotten jarred.I know it is inside the tank,But hey,Wierd things happen when you hit potholes. Probley would not hurt to look into the crankshaft sensor as well.Good Luck.Diesel 1962

[atv087]

theres some kind of sensor i believe a crank sensor ive heard of those coming out after hitting a huge pothole. also if you were very un lucky the engine seized up which could be very costly to fix. Id take it to a professional mechanic if you feel its worth it to fix

[Alibi]

Okay, update.

I appreciate the leads. So far, however, I'm still having problems. Now it is hard starting, idles/runs rough, and smells like too much fuel is going through the system.
Here's what has been checked or replaced since the last post:
air filter
fuel filter--checking for fuel flow from gas tank, felt okay
camshaft sensor
throttle position sensor
crankshaft sensor(that wasn't fun)
MAF sensor
Codes are
21--Throttle Position Sensor voltage high
34--MAF sensor-low gm/sec indicated
41--cam sensor circuit

The next thing i'm going to try is replacing some sort of camshaft pickup magnet located near the crankshaft sensor.

Any more ideas?

[kmohr3]

the magnet on the cam is a good idea..... it's actually part of the camshaft sensor stuff - could have broken off

[DrJay]

That'll be the cam position sensor, vital to performance but not operation (it'll run without it).

The MAF is extremely vital to operation and performance so I would look into what could be wrong there. One common issue is that it simply gets dirty. Pull the MAF and use some electrical cleaner on it. Be VERY careful of the wires. Takes just a few minutes and should be part of regular maintenance.

The TPS is just a rheostat so it's quite easy to test. Turn the ignition to run (do not start) then tap into the lines going to the TPS. You should see 5v on one side and between 0.30-.70v on the other at idle. 0.70v is the high end, if it's above that loosen and adjust until you get the proper reading. You won't be able to adjust it a whole lot, but it may be just enough. Open the throttle body fully and you should see 4.2v+ (as close to 5v as possible).


Hope that helps.

[Alibi]

Now i'm finally getting somewhere. The interrupter magnet seems to be the problem. My bro and I have the same car/engine so we put them side by side, took off the front pass. tire and splash guard. From there we removed the camshaft sensor and cranked the balancer around until the spot where the magnet would be came into view. (Can be seen from hole where camshaft sensor goes). My brothers needs replacing as part of the magnet seemed cracked off. Mine is completely MISSING!

This would explain the code 41 I got. the camshaft sensor was basically not working because the magnet wasn't there. Any advice on replacing the magnet? Note that I don't have power tools to take off the blasted harmonic balancer(especially the highly torqued retaining bolt). I've checked elsewhere and it appears the oil, engine coolant, and water pump may also need to be drained out/removed.

Thank you for the leads so far everyone.

[Stormysdad]

Don't need power tools to take off Harmonic Balancer. I've done it several times with a $11 gear puller from Harbor Freight. This thing right here: http://www.harborfreight.com/cpi/cta...emnumber=37824
If you watch what you are doing you can get the hub bolt off with a long extension, a breaker bar and a length of pipe for leverage. Pull off the inspection cover on the flywheel and use visegrips on the flywheel to hold it. Drop a little liquid wrench at the joint between the bolt and hub, and just reef on the breaker bar. Watch what you are doing, i.e. don't let the socket (USE A 6-POINT SOCKET!) slip off the bolt, and keep all your force in line. I've done this several times. When you get the bolt out you will need a spacer to slip into the hole in the crank snout to give the puller bolt something to pry against, and three 3-5 inch long metric bolts (think they were m6x1) to attach the puller to the hub. There are three threaded holes in the inner half of the hub, look thru the oval holes in the outer half with a flashlight and you should see them. Once you've got it off, you'll say, wow that was easier than I thought. Have fun.