So I went To The Dealer........

birdman_stang

Registered User
k guys i brought my stang to the dealer to have a diagnostic run to see why im misfireing.... on the bill they wrote.. performed PCM self test. retrevied code P0340. fuel pressure test 34 PSI o.k...... then on the estimate they wrote
Fuel press test..... $ 49.50
Compression/ Cyl leak test (possible internal damage??).... $ 298
Check Camshaft sensor sycroniaztion..... $ 217
(possibly replace sensor)

they also said they might have herd a knock

so i only got the diagnostic done... and decided to see what the guys on SCCOA thought i should do because i dont really know a whole lot about motors... but my dad n my gf's dad do..... so what do u guys think?
 
what happenes when the sensor goes..... i looked around on the net and some symptoms of a bad sensor is engine running rough... so maby its the sensor... if it is how do i test it or swap it for a new one... and arew they expensive..... sorry for writing so much about my car... i love driving it and were runing out of good weather but im geting low on funds
 
A new cam sensor is pretty cheap from Ford, $58.11 wholesale price. Could cause a running problem, sometimes they throw the check engine light without having a running issue.


cheers
Ed N.
 
Assuming that this is a 3.8 that we are talking about, it's on the top front of the motor, toward the passenger side. It fits where the distributor used to go on the 80's 3.8s.
 
so i read a lil in my haynes manual... i started the motor and pulled plugs off one by one... the #4 plug doesnt make a difference at all, and when i pull the 33 plug the engine shuters a bit, but not nearly as much as #1,2,5... so i hoping its the cam sensor... what do you think???? could it be a hung valve.. is that common for theese engines??? or maby the DIS is messed?? any input would be very helpful
 
need more info ....I'm guessing this is a SC motor in a stang ... po340 is a OBD2 code ..where as for the rest of us ...we are OBD1 in 1996 everything went to obd2 http://www.obd-codes.com/trouble_co...shaft-position-sensor-circuit-malfunction.php
in your trouble shooting ...swap #3 and #4 plug wires on the coil ...the coil fires the cylinders in pairs 1&5 2&6 3&4 ...and see if you get the same results as you have now ...in your test ....I would also try pulling #3&#4 plugs out ground them.. and turn the motor over ..to see what type of spark you are getting.. if it's a nice blue colour good ... orange bad and ..if they are firing together and again swap the wires that will eliminate the plugs. wires and coil pack ....you may be able to tell ..if it's getting fuel to #4 ...by the colour of the plug tanish brown normal...white ..lean ..may point to a bad injector...dry black rich... wet black...oil fouled or no spark and fuel fouled..and will smell of fuel ... but really need pull them all to compare ... other things to check would be harmonic balancer ..does it run true no wobble...is the bolt still in the crank and tight ...again more history would be nice ..did this motor run right before ...does it have good steady vacuum reading at idle between -17 and -20 ...does it idle .. where is the miss fire at idle or when it goes into boost ... dave
 
it has perfect vaccum 19psi at idle it idles fine and drove fine.... it started acting up after i came back from detroit... when i was in detroit my water pump gasket failed and i got a shop there to replace it... it drove fine all the way home... it wasnt till a week later (2 weeks ago) that it started having a miss.... in low rpm's the car shutters, and lacks power... but seems to drive alot better after 30kmh
 
ok i pulled the plug today on the #4 cylinder and used a test plug on the wire... it sparks great... then tryed the plug and it sparks great... the cylinder defiantly had compression.... also the plug was still brand new lookin no black residue and very little gas smell..... sooo were leaning towars a clogged injector... what do u think?
 
I'd check the crankshaft position circuit as well since you said the problem started after you had the garage change the water pump. They may have damaged the the sensor or put it out of snync somewhat.
 
I'd check the crankshaft position circuit as well since you said the problem started after you had the garage change the water pump. They may have damaged the the sensor or put it out of snync somewhat.

ok but there isnt fuel getin to the #4 cylinder and it has very low compression... would the CPS cause that too?
 
Back
Top