Anyone in utah available to help?

Backtobirdy

Registered User
I'm in the ogden area, I have a 90, 35th anniversary sc. 134k. Clean with a few blemishes. Overall she's a 7 outta 10. It's my 4th sc. Others I've lost due to divorce etc. Anywhoo... this black Beauty... I just can't get it to act right. I'm think crank sensor, or dis. Your thoughts? Anyone in salt lake or ogden area care to help out?
Here's what she does.
Crank, crank, crank little throttle and fire.
Sputters, bogs the rpm's and dies.
Give her throttle she screams and revs great!
Let off the throttle and she bogs down, up, down and tries to die.
No up shift light while cranking btw.
Unplug MAF and it seems to smoothen out idle, haven't taken it down the road this way yet.
Just swapped out the HB due to a stripped pulley bolt and got rid of the slight wobble.
Ok, so a little testing goes like this....
Tried to get her to go down the road, ok cool.... she takes off, and shifts smooth, then like it bucks and Jerks and won't shift like it's confused on what to do, no matter the throttle. More is bad, less smoothes out but will not shift due to rpm's I'm guessing.
Let's see... oh, I can hear the fuel returning into the tank, but it's like a surging, not a constant flow. U can hear it in the car, rather annoying I might add... it's a gush, gush, gush, gush... etc
My thoughts are:
1- crank sensor, or
2-dis and the stupid dielectric grease, or
3-bad coil pack? Questioning that one due to the way it revs up and don't miss.
4- fuel pump and low fuel pressure? Not sure yet on that one.
5-bad ignition switch. Due to a 71 Plymouth GTX I had years back, it had a faulty ignition switch. The car ran like dog crap unless I turned the key ever so slightly. Then she'd clean up and be back to screaming! I have an 89 tbird lx in the back shop I was thinking swapping ignition switches out to eliminate the possibility.
After searching, and studying, and searching and more searching. I can't come up with an answer, and lack of parts readily available to swap out and assist with troubleshooting just sucks btw! No CIL's. Anyone maybe have some insight? Anyone near me able to maybe come have a few beers and give her a look over and see if I'm missing something so stupid I should be kicked in the cherries? Thanks all!
 
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sounds like a bad mafs to me, i get all those symptoms when mine goes bad..exp kif you unplug it and it idles better, thats ur clue rite there..
 
I'll try to source out a good used one to try it out. Thanks for your input! Would a bad maf cause a hard start issue though? I wouldn't think so on a start up. Maybe I'm wrong.
 
Also what about the jerking, or hesitation to shift? Maf? It seams almost confused on weather or not to shift dur to rpm's not being where they should be. It's odd is all I know.
 
Good morning

I recommend:

(1) Pull codes.
(2) Fuel pressure test.
(3) Fuel filter inspection.
(4) Inspect the DIS harness for connector/wire breaks. Now would be a good time to check for heat sink on the DIS.
(5) Swap out the cam sensor.


Good Luck.
 
Good morning

I recommend:

(1) Pull codes.
(2) Fuel pressure test.
(3) Fuel filter inspection.
(4) Inspect the DIS harness for connector/wire breaks. Now would be a good time to check for heat sink on the DIS.
(5) Swap out the cam sensor.


Good Luck.

Good morning to you too, I'll get a psi tester for fuel, I need to read up on how to pull codes, but will! Fuel filter... check!
DIS harness looks excellent, no breaks, dielectric grease looks dry on the edges. I'll pick some up and re-coat it. Thank you for your response! And you want me to swap out the cam sensor... I'll have to order 1 in at 35 bucks. But will do if you feel it may be bad but there are NO issues with the tach whatsoever tho.. wouldn't that be a sign?
 
a test for the cam sensor is to just unplug it. FREE!!! It may take a couple tries to start as the computer "guesses" when to fire injectors, 1 out of three. You will also lose tach signal (that can also be a sign of problems with the sensor , mine actually ran better when the tach went away during the bucking/surging events). I have had bucking/surging problems from bad signal from cam sensor, worth a few minutes b4 you go buy one

Adam
 
a test for the cam sensor is to just unplug it. FREE!!! It may take a couple tries to start as the computer "guesses" when to fire injectors, 1 out of three. You will also lose tach signal (that can also be a sign of problems with the sensor , mine actually ran better when the tach went away during the bucking/surging events). I have had bucking/surging problems from bad signal from cam sensor, worth a few minutes b4 you go buy one

Adam

Thanks Adam! So unplugging it will tell me what? If it starts and runs the same it's the cam sensor, if it don't start it's good? I'm confused on this one.
 
K, so I unplugged the cam sensor. 1st attempt, no start. 2nd attempt, with throttle she started and ran just like she has been. Rough idle, etc. No CIL's but the tach stopped working. Still need to get the fuel pressure tested, and dielectric grease. Thinking pulling the cowl and looking for vacuum leaks. It's holding 12-14# of vac. If I push slightly onot the throttle it'll vac to 18ish #'s. Where should vacuum be? I'll post up results after dielectric grease.
 
If it had cleaned up it would have been a bad cam sensor. No change makes me believe it is something else. Not sure where to go next tho...

Adam
 
Thanks for the input. Ya I just got some dielectric grease, gonna a truly it, and test fuel pump pressure when I get home. Thanks for the replies
 
Ok, checked fuel pressure. 32# KOER and KEOO. Running it I never seen more than 34#. I jumped (grounded) the fuel pump by the cowl, never seen any more pressure increase. Wot never seen more than 34#. After jumping (grounding) the pump for a while, off and on, off and on, WHILE doing wot bursts I don't have the gushing sound anymore, it's more constant and I saw 36# max. The pressure never bled off after shut off. Initial test shown 28-30# fluctuating back and forth. After I was done, the car started easier, quicker, didn't have to hit the throttle to get it to fire up, and the pump sounds better, more constant! So I grabbed a new fuel filter, I'll install tomorrow after work and post results! With the lack of fuel pressure, but holding solid, would the regulator be good? And also would it prevent it from wanting to shift due to lack of rpm's and cause the bucking I described earlier? Thanks for everyone's help!!! We're almost there!!!
 
Getting closer!!!!!

Ok, pulled codes. Got 2, 2 digit codes. 66 and 95. Maf and low fuel pump voltage? Is that right? Also swapped out the fuel filter. Gave her a cpl down the road runs. It hesitated to shift, sort of bucked a few times, and then I stopped hearing the humm, humm, humm, humm from the pump and it was a constant buzz! But that was short lived and the erratic humm, humm, humm, humm came back. But then it disappeared again and was constant again! What gives? When it was constant the bird hit all the gears, boosted, shifted sooo smoothly! Then the erratic hum came back and idle got a bit rough again... pressure regulator? Or is the fuel pump holding on by its last leg and gonna give out on me soon? My buddy took my psi tester to check a few fuel pumps at the wrecking yard for his little car, so I couldn't see if fuel pressure improved, or where it was at WOT.

Thoughts? Ideas? The fuel tank is nearly empty, if I'm gonna drop this tank, just go stock? I have no upgrades, the car is bone stock, no over or underdrives, stock exhaust, and will remain that way. I don't need a bigger pump do I?
 
codes

yes, my code reader manual shows

'66' = maf sensor fault (below min voltage)

and

'95' = fuel pump secondary circuit fault
 
yes, my code reader manual shows

'66' = maf sensor fault (below min voltage)

and

'95' = fuel pump secondary circuit fault

Code 95- fuel pump secondary circuit fault? Soo.... weak, or bad fuel pump? Drop the tank and install a new one? And I'll try cleaning the MAF. Not sure about the "below min voltage" will be addressed from cleaning it, if not I'll have to source a known food one, or break down and scrape up the funds for a new one. :eek:
 
Code 95- fuel pump secondary circuit fault?

The fuel pump is powered by a relay (IRCM), and its secondary circuit is monitored by the EEC. The primary circuit also powers the EEC itself, so if that's out, the EEC would not come on, so no self test or codes. So the most likely failure is in the relay (also in IRCM). Check the EEC ground at the bolt on the header in front of the battery.
 
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The fuel pump is powered by a relay (IRCM), and its secondary circuit is monitored by the EEC. The primary circuit also powers the EEC itself, so if that's out, the EEC would not come on, so no self test or codes. So the most likely failure is in the relay. It might not hurt to swap the EEC relay on the odd chance it's intermittent and not yet full failed, and then clear codes and check again. Check the EEC ground at the bolt on the header in front of the battery.

Wow I just got completely confused... but what I'm understanding is, switch out eec relay, ok... and fuel pump relay? Also, I cleaned up the ground on the header panel yesterday, just forgot to mention it. I'll pick up relays tomorrow and change them out. Where is the EEC relay located? I'll grab my book to see if I can locate it. Also, are you saying the pump itself might not be bad? It's more a relay issue? I'm leaning towards a good pressure regulator, since it held pressure and I had to manually bleed it off.

I want to thank everyone's input and help with this! I used to be on here a bunch when I had my other 3 birds, but couldn't access the old email so had to create a new account. U guys rock!!!!:cool:
 
Sorry for the confusion. On the SC, both the fuel pump relay and the PCM/EEC relay are in the IRCM. That's the module behind the pass. side headlight, in front of the stock air cleaner box. The relays inside are integrated and not something the average owner swaps out - the fix is to replace the IRCM, and they aren't easy to come by.

I don't have any opinion on the fuel pump until you check pressures - right now I'm just commenting on those two codes.

And sorry if I missed it, but did you pull the vacuum line on the FPR to check for raw fuel?
 
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The EEC relay is in the power control box, under the hood, behind the battery. 'G'. I'm not saying that's the issue, I'm saying that since it's easy to swap and it might play a role, it might be worth eliminating up front. Relays aren't cheap, so be careful about throwing money around on speculation...you might need it later ;)

Again, the fuel pump relay is in the IRCM. That's the module behind the pass. side headlight, in front of the stock air cleaner box. The relays inside are integrated and not something the average owner swaps out - the fix is to replace the IRCM, and they aren't easy to come by.

I don't have any opinion on the fuel pump until you check pressures - right now I'm just commenting on those two codes.

And sorry if I missed it, but did you pull the vacuum line on the FPR to check for raw fuel?
I do believe I pulled the vacuum line off, and no raw fuel. Or I thought I did. That's way behind everything right? Drivers side head in the back?
I'll get my pressure tester back tomorrow and post results. Thanks for the input! I'll check on the relays as well as the IRCM. Thanks again for clarification :)
 
The EEC relay is in the power control box, under the hood, behind the battery.

Ignore that info - it's wrong and doesn't apply to the SC. Don't buy any relays, you may need that money for an IRCM.

Yes, the FPR is at the back of the driver's side head.

Fuel pressure checks are done at idle, under boost, and after shutdown, say at 10 and 30 minutes later.
 
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