BLACK92B4C

- Ok guys, just want to check my opinion here and see if anyone has any other ideas!

- I am working on the 1991 B4C project, got the fuel pump installed yesterday. The car sat over 2 years and the old gas was varnished and smelled horrible. I siphoned out all the gas I could (down to about 3-4 gals left in the tank), dumped 5 gallons of new gas in, and tried to start it.
- The engine turned over, and tried to kick, especially when first starting, but would not "catch"
- I checked the fuel pressure, solid at 40 PSI.
- Sprayed about 10cc of fuel in the TB, and it fires up and dies in a few seconds.
- I hotwired the pump, pumped out all the old gas, and dumped in 5 gallons of new. Still the same story.

So here is my logic: spark is good, fuel pressure is good, must be clogged injectors from setting so long. Does this make sense to everyone? I might just order a new set of Bosch.

Thanks for the tips!

Ed

Big Dave

Ha! I got the same problem with my 92 RS which I converted to TPI... its been sitting for a couple years too. I'm suspecting the same thing as you, stuck/clogged injectors. Mine will start and run, but sounds like its only hitting on 4 cylinders.
I bought a cheap/used set off eBay for "diagnostic" purposes, they're supposed to show up today. I got the fuel rail and injectors out of the car last night, they looked like hell. I'll let you know if this fixes the problem!

Becky'sZ28

The chances of all of the injectors being clogged are unlikely. There is a pressure switch in the oil pressure gauge port in the block, either behind the distributor, or else at the port above the filter. If it is not closing the motor will not run. There should be a test lead near the fuel pump relay that you can monitor with a test light while cranking, If it lights then start checking your injectors. If it does not, then hook up a power jumper TEMPORARILY to the test connector, and try to start it. If it starts and runs then you have found the problem is in the pressure switch. If not, back to the injectors. p.s. did you check the filter? Just because a pump makes pressure does not mean it has volume. A clogged filter will starve the system for gas, starting at higher rpms, then dropping this threshhold lower and lower. In a worst case scenario it could be varnished up and although letting pressure through at a not start condition, it may not let enough fuel by to run the car.
If you need any tech dwgs or wiring diagrams, let meknow. I am a tech and have automotive repair software up to 2005. Mitchell on demand.
Becky W. ASE tech

F-Body Demon

iTrader: (1)

Had the same problem and fixed it this easily...

Take out and clean injectors with carb cleaner

Take out and clean fuel rails with carb cleaner

Then blow out the fuel lines, you could just fire your fuel pump for a moment via the ignition key until it shoots fuel.

Put it all back together with some injector cleaner or preferably seafoam in the tank.

This WORKED for me.

BLACK92B4C

Ok, got a noid light on it tonight, it is pulsing, so that must mean the VATS and ECU is OK....TPS is within limits, no codes...so I am guessing has to be clogged injectors still. I pulled the schrader valve off the fuel rail to attach the pressure gauge and it is pumping fuel to there also, so I don't see anything else it could be.

Becky, I disconnected the fuel hose at the rail to pump out the old varnished gas, it pumped real well...Ilots of volume... did change the filter after too though.

I ordered up a new adjustable fuel pressure regulator, plenumn gaskets, and all the accel tuneup stuff from Summit. They got here today. I am picking up a set of unused OE injectors in the am, so will swap those out and see what happens.

Thanks for the tips, will keep everyone posted! If this doesn't start it I am lost!

Big Dave

I replaced my stock 19lb Multecs with a set of 19lb Ford injectors, and the car runs like a top. Your problem sounds very similar to what I had to deal with, and it turned out to be my injectors. So I'd say cleaning or replacing yours would be worth the time.
Good luck
Dave

DENN_SHAH

iTrader: (1)

there is a good probability the injectors are stuck closed.
that was the problem here,
https://www.thirdgen.org/forums/tpi/...ap-really.html

BLACK92B4C

Thanks guys, found a set of OE replacement injectors that my buddy had on a shelf for like 10 years. IT'S ALIVE! Swapped them out, and did a BBK AFPR with all the tuneup stuff at the same time.


Got it together this morning, hit the key and it fired up and idles smooth. Backed outta the drive and drove it up and down the block, motor feels strong, real responsive.



So here is my problem list now:

- Speedo is inop: Need to hook up the scan master and see if it is VS sensor or dash related...
- Oil pressure gauge is pegged - prob bad sender from sitting so long, but not as scary as zero!
- Power windows are inop
- Rear hatch pull down motor is inop
- Brakes need done
- Horn is inop - Need the horn buttons for the airbag
- Then body work, pretty stuff!

BLACK92B4C

Here's some pics:








And here's a startup video so you all can hear it! (no dial-up, high speed only!)
http://videos.streetfire.net/video/3...8f0141c0d8.htm


I even had enough time to polish up my old Nighthawk. Most of the chrome and stainless trim cleaned up fairly nice. The old bike has spent a lot of days outside in Hawaii weather, some of it was just too rough!