Problems with the 93 Lumnia Z34

[34ford]

The car has a new annoying problem. It quits for no apparent reason. Driving down the road and it kills. Turn the key off tap the accelator once or twice and it fires back up again. It does this from a cold start and also when it is warmed up from driving around town. Wifey is getting annoyed and I'm ready to trade it off..  Any clue as to what the cause is. I did have the throttle body cleaned and the mechanic said it wasn't bad enough to cause any problems. There are no codes showing and the check engine light does not come on. This happens when she is driving or stopped.

thanks

bob

[wayne petty]

first off...  what kind of diagnostic tools do you own...

ROOSTER  where are you...

this whole thing was gone through on a 95 olds with the same motor..  that took a LOT of work.. and i don't recall what the actual outcome was..  i guess we will have to review the many pages.. but starting at the last post.. and moving toward the front of the thread..

http://www.roddingroundtable.com/forums/viewtopic.php?t=11245&postdays=0&postorder=asc&&start=0

i seem to recall that it turned out to be a failing fuel pump... and the harbor freight plug in amp circuit tester found the fuel pump would have the 7 amp draw for a few minutes. then it would increase to 15 amps and then 25 and the engine would die..

do you have a

digital volt meter... yes/no

http://www.harborfreight.com/ac-dc-digital-multimeter-37772.html

AC/DC amp clamp or low amp current probe

or one of the harbor freight 10 or 15 bucks amp meters..

http://www.harborfreight.com/30-amp-automotive-fuse-circuit-tester-67724.html

http://www.harborfreight.com/20-amp-automotive-fuse-circuit-tester-67725.html

these plug right into your fuse and let you see what the current draw is...

harbor freight sells this 22 buck fuel injection pressure tester that will hook up to the test port on your car.. won't work on the smaller sized ford fuel injection test ports..

http://www.harborfreight.com/fuel-injection-pump-tester-92699.html

the Actron/0-100 PSI fuel pressure tester kit with Ford fuel line adapter   Part Number: CP7818  is double the money. but probably in the end run.. a more useful unit..  available at most parts stores..





you MAY also need a scan tool.. that reads live data on OBD1 systems...

http://forums.corvettefever.com/70/8585187/c4-corvettes/which-used-scan-tools-for-82-to-94-corvettes-with/index.html

[rooster]

The car has a new annoying problem. It quits for no apparent reason. Driving down the road and it kills. Turn the key off tap the accelator once or twice and it fires back up again. It does this from a cold start and also when it is warmed up from driving around town. Wifey is getting annoyed and I'm ready to trade it off..  Any clue as to what the cause is. I did have the throttle body cleaned and the mechanic said it wasn't bad enough to cause any problems. There are no codes showing and the check engine light does not come on. This happens when she is driving or stopped.

thanks

bob

Would be a good idea to maybe put a fuel pressure tester on it! If you can get it to die while sitting in the driveway! Watch that pressure! Gotta kinda baby sit it. It took me 2 hours doing it that way! Intermitent fuel pump failure!

[34ford]

did a little research on the web after I posted here and seems there are some indications it could be the crank sensor.

I do have a digital meter.

no other testing gauges.

[rooster]

did a little research on the web after I posted here and seems there are some indications it could be the crank sensor.

I do have a digital meter.

no other testing gauges.

Not sure on your year but I think if it were the Cam or Crank sensor you should get a SES light on your dash!!!!

You could find the fuse that feeds your fuel pump and "in seris" hook up your meter and  amp draw of the pump should be around 6.8 amps, if the amps go ape S(*&  just before it dies you found your problem!
You have to watch the amp meter very close!! It all takes place in about 2 seconds before engine dies! If you have to video tape it! It will go something like this: Car running just fine, amps start climbing(pump binding) , presure drops, eng stops!, pumps cools just abit and car restarts, NO SES light !

If it is the pump you would be much better off if it would just drop dead!LOL

I replaced all those sensors and it wasent needed!
Also 2 computers
replaced wiring between injecter drivers and injecters.
harness plugs
Crank sensor twice

None of this was needed!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Make sure your meter is fuse protected!! Harbor freight sell a small meter just for doing things like this for about 15 bucks. On the 95 OLDS the fuse was under the hood by the relays. http://www.harborfreight.com/20-amp-automotive-fuse-circuit-tester-67725.html

[34ford]

The bad thing about this is it never quits at home. It is always when the wife is gone from the house. It did it once in the garage and I wasn't home. Thanks for the info. Will get one of those meters and see what kind of amps the pump is pulling.

Thinking I need to trade this problem child off but it only has 70,000 miles and it's a 93, paid for and cheap plates.
bob

[rooster]

The bad thing about this is it never quits at home. It is always when the wife is gone from the house. It did it once in the garage and I wasn't home. Thanks for the info. Will get one of those meters and see what kind of amps the pump is pulling.

Thinking I need to trade this problem child off but it only has 70,000 miles and it's a 93, paid for and cheap plates.
bob

I think our Olds had about 65K on it when it went south.

Be careful driving that thing the way it is! If eng dies at 70mph you lose steering power and brake VAC, even if it dont start you can turn it over to get the vac back. Another twist is that the steering wheel can LOCK, as you turn the key to off position, to re-start while moving. You might check that to see if it locks in netural position! not sure!

[wayne petty]

i have been out all day working on reassembling the 4.2 intake.. and my head is STILL hurting from hitting my head into the A pillar 2 days ago..

http://www.speedwayautoparts.com/aFuel%20Deliverly%20Testing%20and%20Diagnostics.pdf

this is only 3 pages and not all of it covers the electric fuel pump tests..


its pretty straight forward...  the FUEL pump AMP draw should NOT vary much.. under load. it might increase...

i would imagine that you can send power directly to the ALDL pin G with the ignition key off for direct fuel pump only testing..  as this is a normal test configuration..

battery power to  the meter in 20 amp DC.. the other probe to the G terminal on the aldl with the ignition key off should send power to the Normally closed contact and directly to the fuel pump wiring..    bypassing the fuel pump relay .. warning. this stops as soon as you turn the key on..

its a fuel pump prime connection only..

its a TON easier to buy the proper HF plug in amp circuit tester. and monitor the amp draw with the engine running..

find the fuel pump fuse...