I've been battling the horrible performance my TGP has had and I think I've narrowed it down to clogged or bad injectors.  But today (after letting the car sit for four days) it just cranky cranky and no start.  I have spark and the fuel pump is good so I have eliminated the obvious.  I'm just wondering if the injectors can cause the no start thing now???  I have changed the O2 and the MAP and it already has Jeff's chip and x-over as well and two weeks ago I gave it a complete tune up so any ideas????

A couple of questions...and you may want to be a little more specific when you post issues. ;)

How do you know you have spark? How did you check it?

How do you know the fuel pump is good? Did you test fuel pressure at the schrader valve on the fuel rail?

Also have you ohm'd out the injectors to see if they have shorted?

Let us know... :icon_cool:

sounds like a possible bad crank posistion sensor.

That is why I asked...how did he check for spark. Wouldn't a bad crank sensor still allow spark...just very irratic? That would also explain the bad running and chugging idle.

But we need to know more before we can internet diagnose! ;) :icon_cool:

Right on...MAYBE I left a few details out  :icon_eek:  I had the car to a CERY good friend of mine who is also a mechanic...albeit he has never worked on one of these...BUT he did check all of the above with the exception of the crank, injectors and TPS as he does not have the correct codes for them and he did tell me he didnt want to "guess" which is one reason why I trust him.

As far as ohm testing the injectors I though the best way was to test each one for proper pressure by pulling them and testing.  I'm not sure how to ohm test them as I thought outside circumstances COULD drive the outcome of that test???  I'm not saying that I know I'm just asking as I do not know (which is why I'm asking you guys  :icon_mrgreen:)

I dont mean to leave anything out but just asking so I can learn!

The injectors can be tested without removing them.

Take off plenum and unplug injector connecters.

And ohm test the injectors that way?  What should the readings be for these?

Aged...but Good injectors will be between 12.0 - 12.4

Anything UNDER 12.0 will begin to be suspect of deterioration of the windings.

If you are 11.0-11.5 and under they MUST be replaced!

When you pull the EGR tube, Throttle Body, upper plenum (BE VERY CAREFUL OF PCV VALVE HOSE) and unplug the injector connectors you will see two spade connectors...just use a DVM (Digital Volt Meter) to read them.

A FRIENDLY REMEMBER... you are working on a 16 year old car...the plastic vacuum lines are EXTREMELY BRITTLE as well as the PCV hose. If you watch what you are doing and stop when you feel resistance on something you are taking off you should be ok when things go back together.  ;) :icon_cool:

UPDATE - I pulled the plenum and paused at resistance like you suggested.  The PCV hose was in three pieces and the PCV itself was so full of black goo it could hardly move.  I replaced both and ohm tested the injectors.  The very first one on the forward most fuel rail and closest to the fuel feeder on the right side read 9.5  :icon_eek:  I checked all the rest and they all ranged from 12.2 to 12.4.

So now I have to find an injector that matches or I can replace them all with 19# that I do have.  But the problem still remains that the car will crank but it will not start.  Is it possible that this one injector is the cause?

One injector will not cause a no start...it will run roughl...but not a no start. 9.5ohms is dead and will need to be replaced. DO NOT USE A 19# injector...especially mixed with the stock injectors. All you will do is melt that piston if you get in the throttle. I would think it would run rough anyway.

Jeff M has some stock injectors that he may sell individually, but for the price of two you can nearly buy a full set of 3800 (L36) injectors. With the 3800 injectors you most likely would need to tweak the chip slightly to keep it from running rich...but 6 brand new injectors always sound good to me. Have a look here for what we were talking about... http://www.tgpforums.com/index.php?topic=2954.0

Have you tested the fuel pressure at the schrader valve on the fuel rail? If so what was your pressure? Static and during cranking?

Also I didn't see "how" you tested for spark. Need to know that to see if maybe your crank sensor is dead or dying.

Let us know...Kenny :icon_cool:

my 2 cent post: Taylor 8mm. 74030.  goodbye now.

Lets say the car has spark because the machines said so   ;)  Would the CPS cause it NOT to start but just crack like hell and sputter once in a while?????

Quote from: GangstGP on March 23, 2006, 02:42:40 PM
my 2 cent post: Taylor 8mm. 74030.  goodbye now.

And that would be plug wires?

Yes the CPS can cause that if its messed up and yes those are plug wires he mentioned

Well that just sucks  :icon_mad:  The CPS can go from good to bad just like that?  I just replaced the plugs and the wires last week so I'm leaning on the CPS just went bye bye.  The car started (not easily but it did eventually start) last Thursday and when I went to get in after the weekend it would just crank and crank so I'm going to go get a new CPS and try that.