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Topic: Drivability issue...LONG post, SOLVED!!!!! (Read 2757 times) previous topic - next topic

Drivability issue...LONG post, SOLVED!!!!!

A little over a week ago, I was driving home in severe rain...roads were starting to pond up pretty bad and I hit about 1-2" of water at about 50mph and the car started running rough...

Symtoms:
Rough idle, misfire under a load, runs silky smooth under an extremely light load. 

ONE-TIME fault:
drove the car for about a week like this, then one day while returning to work from lunch, couldn't keep an idle, repeatedly stalling, while decelerating in gear you could hear the motor go flat through the exhaust, hit the gas and it came back to life...I pulled into a gas station and could only keep it running by feathering the throttle rapidly and it was puking black smoke out of the exhaust. MAF voltage was all over the place.  Disconnected MAF air adjuster and plugged MAF back in and it's been running consistently py, but drivable since.

SPECS:
5.8 with 24lb/hr injectors, CV 73mm MAF with center bar removed and fox mustang electronics, MAF air adjuster(modifies maf signal to adjust for changes in injector size), mass air ecm for '89 GT AOD.

pulled codes and got the "normal" 81, 82, 94, 44 (air mgt. 1 ckt failure, air mgt. 2 ckt failure, thermactor sys. inoperative #1-4, thermactor sys inoperative #5-8), I have no air pump on the car and when re-pinning the harness, I did not pin the TAB and TAD back in as they were useless anyway, I also got a code 33 for egr not opening, which is new a new one by me.

I checked for vac leaks by smoke testing the intake and vac lines, all good
Spark plugs are good (none cracked), plug wires are good(none breaking down), ignition coil is good (swapped with a new one, no change), MAF is good (swapped with known good, no change), fuel pressure is good(according to my rail mounted gauge), replaced TFI module with no change.

Pulled apart "salt & pepper" connectors, maf connector, tfi connector, O2 harness and coil connector to check for moisture, all looked good.  I pulled all the plugs and they all look identical, none wet, indicating to me a random misfire under load.  It's also not a "dead-miss" at idle, as pulling one plug wire off at a time @ idle resulted in a significant change in idle quality on every cylinder.  My air/fuel ratio gauge goes bat-shiznit crazy when it misfires under a load.  I still have some pretty erratic MAF voltages also.

If I think of anything else, I'll post it up...I won't post up my suspicion just yet, because I don't want to lead anyone down the wrong diagnostic road.

PLEASE HELP!!!

Thanks in advance,

Don
Project 3G: Grandpa Grocery Getter-'85 Crown Vic LTD 2-door, 351W with heavily ported/polished GT40 heads, heavily ported/polished Typhoon Power Plus upper & lower intake, Comp Cams 265DEH retarded 1*, FAST EZ-EFI, HD T5, 8.8" 3.73 trac lock with extra clutches, 3G alt. swap, '99 CVPI front brakes, '09 CVPI rear disc brakes, '00 CVPI booster&m/c + wilwood adj prop valve.

Parted & Gone-'88 T-bird Sport, 351W swap, ported GT40 heads

Drivability issue...LONG post, SOLVED!!!!!

Reply #1 –
My guess is pull and clean the MAF sensor.  Sounds like you got some water up and into the air filter and it is on the MAF sensor.  Use brake cleaner and very lightly use a cotton swab to clean it.  Follow this up with some CRC electric contact cleaner to remove any residues.

Darren

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

Drivability issue...LONG post, SOLVED!!!!!

Reply #2 –
I checked the filter and it is dry...I had also replaced the MAF with another known good unit and it had no effect.  I'm almost wondering if there is an issue in the ECU with the 5v reference voltage supply...I don't have my DVOM with me this weekend...I may go buy a cheapo meter so I can check on some stuff....wondering if maybe water got in a connector somewhere and shorted something in the computer...IDK at this point.

Thanks,
Don
Project 3G: Grandpa Grocery Getter-'85 Crown Vic LTD 2-door, 351W with heavily ported/polished GT40 heads, heavily ported/polished Typhoon Power Plus upper & lower intake, Comp Cams 265DEH retarded 1*, FAST EZ-EFI, HD T5, 8.8" 3.73 trac lock with extra clutches, 3G alt. swap, '99 CVPI front brakes, '09 CVPI rear disc brakes, '00 CVPI booster&m/c + wilwood adj prop valve.

Parted & Gone-'88 T-bird Sport, 351W swap, ported GT40 heads

Drivability issue...LONG post, SOLVED!!!!!

Reply #3 –
Have you just unhooked the battery and let it sit about 10-30min then hook it back up. Get everything out of it back to BASIC. Then it retest all your sensors and start with those values. Sure sounds like something got wet and needs dried out or replaced. Also never over estimate the factory grounds, Add many and much larger better grounds plus replace the factory. I added 2 sections of 4ga cable about 2feet long on each side of my motor and then Upgraded the Factory rear ground strap to 4ga cable and the Norm ground to 4ga cable and the car starts like never before. That was before the Newer gear reduction style starter, now with that its even easier to get her going. Grounds grounds and grounds. It will help everything in your whole car. Especially keeping voltages steady "less fluctuation". Hope you get it lined out soon. I'm in the same sorta boat on my bird.

Stuckman
84 Turbo coupe 2.3T Modded with 88 upper and lower intake, 88 injectors, E6 manifold, T3-4 AR.60 turbo, 31X12X3 FMIC, Homemade MBC , Greddy knock off BPV.
4 eyes see better than 2! 
Da Bird!

FreeBird

Drivability issue...LONG post, SOLVED!!!!!

Reply #4 –
+1 to Stuckman's post, esp grounds


Did I miss the ignition description?  If TFI, replace w/ Motorcraft.
__________________
Twin '85 TCs
White/ Grey 2-tone
#1 (left): undergoing top-to-bottom rebuild     
#2 (right): DD, power everything (sorta)
[SIGPIC][/SIGPIC]

Drivability issue...LONG post, SOLVED!!!!!

Reply #5 –
I didn't even really think to check grounds...I guess I'll do that after the holidays.

This morning, I plugged a vacuum line back onto the Map/Baro sensor, disconnected the MAF and plugged the factory SO computer back in...just for shiznits and giggles...it idled much worse as I antited, but the misfire was still there under load, so I'm assuming it's not an ECU problem.

I guess my next order of operations is- check grounds, check sensor values and if all is good, I suppose pull my upper plenum and check all the injector connectors for moisture/corrosion.  Sound about right?

Thanks,
Don
Project 3G: Grandpa Grocery Getter-'85 Crown Vic LTD 2-door, 351W with heavily ported/polished GT40 heads, heavily ported/polished Typhoon Power Plus upper & lower intake, Comp Cams 265DEH retarded 1*, FAST EZ-EFI, HD T5, 8.8" 3.73 trac lock with extra clutches, 3G alt. swap, '99 CVPI front brakes, '09 CVPI rear disc brakes, '00 CVPI booster&m/c + wilwood adj prop valve.

Parted & Gone-'88 T-bird Sport, 351W swap, ported GT40 heads

Drivability issue...LONG post, SOLVED!!!!!

Reply #6 –
I am interested in this since I have the same setup as you Sick. BUt I have a wierd idle issues. I run my car for a bit. Shut it off. Then restart and I get a terrible hunting idle in gear stopped. If I put it in neutral it is fine.

Let me know what you find out.
1988 Thunderbird Sport. Work in Progress
5.8L swap w/fitech efi, 4R70W swap w/quick 4 controller, 2003 GT rear diff, 5 Lug swap

Bought this car back as an old project car.

:burnout:

Drivability issue...LONG post, SOLVED!!!!!

Reply #7 –
Did you check the distributor and the ICM? I had the same problem with mine a lil while back and i had moisture in the distributor. I didnt notice if you said u checked that or not, so i thought id mention it.
Remember, if the women dont find you handsome, they should at least find you handy.

When all else fails, get a bigger hammer.

Chris
 93 cat rebuilt 3.8

Drivability issue...LONG post, SOLVED!!!!!

Reply #8 –
One of the first things I checked for was moisture in the distributor cap....of course I forgot to bring my DVOM home this weekend to check sensor values and grounds.
Project 3G: Grandpa Grocery Getter-'85 Crown Vic LTD 2-door, 351W with heavily ported/polished GT40 heads, heavily ported/polished Typhoon Power Plus upper & lower intake, Comp Cams 265DEH retarded 1*, FAST EZ-EFI, HD T5, 8.8" 3.73 trac lock with extra clutches, 3G alt. swap, '99 CVPI front brakes, '09 CVPI rear disc brakes, '00 CVPI booster&m/c + wilwood adj prop valve.

Parted & Gone-'88 T-bird Sport, 351W swap, ported GT40 heads

Drivability issue...LONG post, SOLVED!!!!!

Reply #9 –
As of today, I have checked all my grounds, sensor values and electrical connections....I even tried another computer, MAF, coil, and TFI module...plugs and wires are good...at least the plugs appear to be good, no cracks.

I also back probed my injectors at the black connector on the back of the intake....my values @ warm idle with DVOM set to DCV was between .14v-.29v...no single one did anything much different than any other...this would indicate to me that I don't have any moisture in any of my injector connectors.

Any ideas other than replace with carb?

Please help...I've been lookin at buying Chevys!!!!

Thanks,
Don
Project 3G: Grandpa Grocery Getter-'85 Crown Vic LTD 2-door, 351W with heavily ported/polished GT40 heads, heavily ported/polished Typhoon Power Plus upper & lower intake, Comp Cams 265DEH retarded 1*, FAST EZ-EFI, HD T5, 8.8" 3.73 trac lock with extra clutches, 3G alt. swap, '99 CVPI front brakes, '09 CVPI rear disc brakes, '00 CVPI booster&m/c + wilwood adj prop valve.

Parted & Gone-'88 T-bird Sport, 351W swap, ported GT40 heads

Drivability issue...LONG post, SOLVED!!!!!

Reply #10 –
Ummm any chance you got a bunch of water in the tank during that storm??? Also I assume you've verified the fuel pressure diaphragm isn't leaking...

Drivability issue...LONG post, SOLVED!!!!!

Reply #11 –
Any chance it ingested enough water through the carb to bend or crack something in the engine?

Drivability issue...LONG post, SOLVED!!!!!

Reply #12 –
Quote from: TurboCoupe50;329393
Ummm any chance you got a bunch of water in the tank during that storm??? Also I assume you've verified the fuel pressure diaphragm isn't leaking...


I was just thinking about water in the fuel...but I was wondering how I would get enough water in the tank to cause such a problem.....I'm just about out of gas now, so when I refuel we'll see.

I don't see any visable fuel leaks from the FPR, it's a holley adjustable unit...my fuel pressure is @ 38psi w/vac and 45+ without.  Which is right where I set the regulator, so I'm assuming that it's okay and not leaking internally/bypassing fuel.

The owner of the shop told me he encountered an identical problem about 10 years ago on an early 90's F-150...they had the truck for months and tried everything...the fix was replacing the FI with a carb...that's not for me.

Thanks,
Don
Project 3G: Grandpa Grocery Getter-'85 Crown Vic LTD 2-door, 351W with heavily ported/polished GT40 heads, heavily ported/polished Typhoon Power Plus upper & lower intake, Comp Cams 265DEH retarded 1*, FAST EZ-EFI, HD T5, 8.8" 3.73 trac lock with extra clutches, 3G alt. swap, '99 CVPI front brakes, '09 CVPI rear disc brakes, '00 CVPI booster&m/c + wilwood adj prop valve.

Parted & Gone-'88 T-bird Sport, 351W swap, ported GT40 heads

Drivability issue...LONG post, SOLVED!!!!!

Reply #13 –
Defective effing spark plugs!!!  They looked fine every time I checked them.  I came back from vacation this past Saturday and Sunday morning put in a set of E3's(for the fuel economy, not the super amazing ricer power gain) and the car now runs like a dream.

The only reason I decided to go ahead and change the plugs anyway was because we've been dealing with a lot of defective Autolite spark plugs...resistors, platinums and even double platinums.  We've had a lot of new plug failures without any cracks or burn-though....well, by a lot I mean 4 different cases of failure in a 7 month period...that's too many.

Thanks to everybody,
Don
Project 3G: Grandpa Grocery Getter-'85 Crown Vic LTD 2-door, 351W with heavily ported/polished GT40 heads, heavily ported/polished Typhoon Power Plus upper & lower intake, Comp Cams 265DEH retarded 1*, FAST EZ-EFI, HD T5, 8.8" 3.73 trac lock with extra clutches, 3G alt. swap, '99 CVPI front brakes, '09 CVPI rear disc brakes, '00 CVPI booster&m/c + wilwood adj prop valve.

Parted & Gone-'88 T-bird Sport, 351W swap, ported GT40 heads

Drivability issue...LONG post, SOLVED!!!!!

Reply #14 –
Nice.

How do you like the E3's?
1988 Thunderbird Sport. Work in Progress
5.8L swap w/fitech efi, 4R70W swap w/quick 4 controller, 2003 GT rear diff, 5 Lug swap

Bought this car back as an old project car.

:burnout: