Online Helps

ONLINE SERVICE FOR YOUR VEHICLE Right Here
=======================================================
Paragon Motors.ca   eMail PARAGON MOTORS BARON ROAD KELOWNA   250-762-6006
----------------------------------------------------------------------------------------------------------
On Tue, Aug 17, 2010 at 7:33 PM, Jim Davies <lighthouse_transport@yahoo.com> wrote:

I seem to have the same problem as the person in your story with the 94 Jimmy but mine is a 95. Lack of power & poor mileage.But wouldn't a bad ground in an o2 sensor throw a code? I have replaced the plugs, plug wires, dist. cap & rotor, the coil, ignition module, catalytic converter, fuel filter, radiator & thermostat. There are no codes & the fuel pressure is 60 lbs & drops about 4 lbs when I start the engine. Feels like the timing is retarded but it is not adjustable. Any ideas? Maybe an exorcist???

Thanks

Jim

Date: Wed, Aug 18, 2010 at 10:40 AM

Subject: Re: 95 Jimmy
To: Jim Davies <lighthouse_transport@yahoo.com>
Hi again Jim, it is possible my return email did not reach you so here goes.
1. Please send me your complete serial number
2. When pressing the throttle, is there a point that shows no more power, like immediately or part way.
3. Does the engine cough?
4. Does the engine throb?
5. When listening to the engine while the air filter cover is off, do you hear cracking noises as if the valves are late.
6. Have you considered timing belt or chain problems?
After receiving your auto serial number I believe we can be of better help to you.

Barry
----------------------------------------------------------------------------------------------------------
Hey Dad

This engine may be quite different in 95. He says the timing can't be adjusted so it must be the crank sensor type. The cap looks different - the wires come out horizontal (not vertical) and there is only a cam sensor in the distributor. The timing can't be adjusted but the rotor can still be installed out of time. The Auto scan tool reports how far out the cam sensor is compared to the crank sensor. That confirms whether the rotor is aligned to the cap terminals. At #1 tdc the rotor should point to a mark (little triangle) on the distributor.
Chains don't seem to jump any more even though they get quite noisy. Maybe it was assembled 1 tooth out??
I wonder what the Auto fuel pressure is under load. If it drops under load the whole engine quits for a moment. That's because of the central fuel injection. Below about 40 psi the injector pintals will not open and fuel flow stops while the pump catches up.
The O2 sensor ground did not set a code.
A common problem is a leaking fuel regulator. It's in the intake manifold. Take the upper half off to see it. Pressure the fuel system and you might see a leak. If one monitors the fuel pressure with the engine off, it may drop slowly all the way to zero if the regulator leaks. Auto Gas mileage will be bad and it will run rich on a couple cylinders. It may also cause the pressure to drop under load because to much fuel may bypass to the tank. Anyhow - watch the Auto fuel pressure under load and after turning off the engine. Should tell us something.
I think the best bet is an advanced distributor. Few people know how to put it back in properly.
That help?
Rick                                                    The End!


----------------------------------------------------------------------------------------------------------