Fuel pump issues. I think

[HeatherBelle]

I am moving my thread from misc. to here. (Suggested). I few weeks ago 96 ImpSS Would run a little shoddy when cold. I thought tune up, but then one day it started popping, hesitating, backfiring. After that it just wouldn't start at all. She would just turn and turn. Checked all spark plugs and wires everything looked fine. Went on to fuel. I only put 94 high octane from shell. When key was put in ON position I couldn't hear fuel pump switch on and start prime. Now I have replaced fuel pump. And same ****. Won't run. Anyone have this problem before?

[angelo]

Step 1.
check schrader valve for proper fuel pressure. 37-42 psi


work backwards until you find why pressure is not up to par...

if pressure is good report back so.

-ALF out...

[HeatherBelle]

Thank you will do.

[BALLSS]

I have found a $30 investment in a fuel pressure gauge for LT1 is worth it. That will instantly tell you if it is a fuel pressure problem. Hypertech makes one but assume others do also

If FP is good...I would look towards the Opti as you note "popping/backfire"...previously. That is a very common signal Opti is dieing or dead.

Unfortunately codes are not always thrown. You can buy a code reader for OBD2 cars (96 and newer) for around $30 also at places like Harbor freight.

FP gauge and code reader along with a Haynes service book can go a long way in resolving problems.

with all this said "your" problem could be so many things but fuel and spark are two initial things to confirm. hard parts can fail but things like poor connections can cause havoc in tracing WTF is really going on.

This forum is full of great help...and some sarcasim.....as you may have discovered in the Misc section.

[streetcar2try]

You can purchase a fuel pressure tester or alot of chain auto parts stores have them for rent. You will connect it to the schrader valve as in the pic above. Unscrew the black cap and install the tester.

You can then use that red wire I mentioned. That is just a jumper wire directly to the pump. That wire is used for testing and diagnostics, which you are doing. It will run the pump even if the key is off. When applying current to the pump, the gauge should read about 40-45psi. It should jump up almost instantly. If it takes more than 2 seconds, the pump is weak, it it doesn't reach at least 35psi, the pump is weak or shot.

If it is an ACD, it has a LTW.

[Bad Imp]

Originally Posted by BALLSS

If FP is good...I would look towards the Opti as you note "popping/backfire"...previously. That is a very common signal Opti is dieing or dead.

^Great advice! We had a club member with the same problem, couldn't figure it out, so decided to change the Opti and whan we pulled it out we could hear rattleing, so took the cover off and foung both screws for the rotor had backed out and off.

[Mr pogo]

Originally Posted by Bad Imp

^Great advice! We had a club member with the same problem, couldn't figure it out, so decided to change the Opti and whan we pulled it out we could hear rattleing, so took the cover off and foung both screws for the rotor had backed out and off.

as she has a 96 I would check for codes also, P0300 stored or active is common when the opti is starting to go.

[HeatherBelle]

Is is all great I formation. I will post back tomorrow with results. Thanks a lot guys, I found out the hard way to stay away from misc. section.

[DougDePew]

Originally Posted by BALLSS

Haynes service book can go a long way in resolving problems.

If you need to start a fire, the Haynes manuals are indeed a great way to resolve a problem.

[cletus284]

I agree with the other posters, just one more piece of advice:

If you don't have a PCM tune to take advantage of it, filling these cars with premium gas is just throwing money away. Save a few bucks, it will run just fine on regular unleaded.