Fuel spills out when filling, poor throttle response (Page 1/2)
Forrest APR 28, 07:36 AM
Hey guys. Thanks for all the help thus far with my 86 GT.
I have checked the cave and other threads regarding fuel spilling out...no dice.
So when I am filling up fuel will spill out of the wheel well. Its quite a bit of fuel so not a small leak. I pulled the wheel and plastics to get a look at the filler neck and it looks solid. Ill get the car up on ramps this morning and see if the leak might be coming from the tank.
I am wondering if possibly the evap lines are clogged.
Compared to my sons 88 GT the throttle response is very poor. The 86 runs good and has good power but it feels like the motor has to wind up a bit when pressing the throttle...where as the 88 pretty much gives an immediate response (waah-pow waah-pow). The cat was removed on the 88 by the PO.
We can get away with that in Tx as cars 20+ years old are exempt from emissions tests.
I put a new fuel pressure regulator, New injectors, EGR valve and tube...that got the idle down to normal levels and it no longer reeks of fuel when running...not as much anyway.
Anyone seen this before?
Clogged evap lines/canister?
Would a clogged cat cause the poor throttle response?
Ready to start the body work on this car but mechanically there are still issues :-(
Side note...recently I have to crank it for quite a while before it will start. It used to fire right up. ( EDIT: Fuel pump relay is out...did the test with the ALDL connector. )

[This message has been edited by Forrest (edited 04-28-2022).]

olejoedad APR 28, 10:53 AM
If it's spilling out of the wheel well, it's not at the tank.
You have a hole in the fill pipe, probably where the fill pipe goes through the space frame .
There should be a rubber pad on the metal edge below the fill pipe, perhaps the pad is missing.

Timing issues will really affect a 2.8's performance and throttle response.

If you aren't required to run a converter, get rid of it. It's probably not any good anymore, or may be partially plugged.

And the exhaust will sound better!
theogre APR 28, 12:40 PM
yes, wheel well leaks is likely the fill pipe(s)...
The pipe have a small vent pipe that splices near the top. Can leak at the splice or anywhere else.

Even if you find a way to aim the nozzle to fill w/o spilling... The leak must be fixed.
Leaks will let Gas Fumes Out and let Air and Water In that in turn will make more problem and worse w/ any alcohol pulling water from air like E10 gas.

IOW that leak maybe the Cause of your engine problems.
When fill pipe is out to fix/replace, siphon the tank to Empty it. Lift front of car to push all to rear to get most of whatever. Then look at container very carefully to see "water" and other crap on bottom. If have a lot, then likely need to pull the tank to get the rest.
Use small very flexible tube/hose w/ weight to get more water helps too. If done careful may save dropping the tank.

Not sure if the fill pipe is SS...
If normal metal w/ galvanize then can be Lead solder to fix. Not Brazing, Too hot and warp/crack the pipe(s).
But...
⚠️ Warning: galvanize steel heated or grinding/sanded can let Zinc crap loose that is poison to breath in.

After fixing/cleaning... carefully put the old gas minus crap w/ fresh gas to burn in the car. If have a lot of old gas, do it over a few fill ups.
E10 Gas after water messes up Octane rating but burns normal otherwise.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

olejoedad APR 28, 12:54 PM
The fill/vent pipes are galvanized mild steel.
Forrest APR 29, 07:28 AM
Did a lot of troubleshooting on the car yesterday.
Got a new relay for the fuel pump. Car fires up fine now.
Poor throttle response: I pulled all the plugs and put in new ones. Several were bad.
Its missing for some reason...was before I swapped the plugs. I pulled cylinder 3 plug and there was no change in the engine.
Checked for spark at the end of the plug wire and it is getting spark.
Checked the injector and it is ticking. I recently put in new injectors...maybe somehow I plugged the wrong wire into one of the injectors. I would think it would be missing on more than just one cylinder if that were the case.
Checked the firing order like 500 times. Its a head scratcher. I swapped out the cap just to make sure there were no issues. Also put in a brand new ICM as I always want a spare on hand (My sons 88 left me stranded cuz I didn't have a spare)


Have not checked the filler neck yet. If Ogre is correct and water is in the tank then I would think it would have random misfires....not consistent.
olejoedad APR 29, 08:56 AM
The 2.8 is a bank fire engine - the odd injectors fire together, the even injectors fire together.

Replace #3 plug wire or pull the plug and recheck the gap and the electrode.
Forrest APR 29, 09:43 AM

Gap is good. This is a brand new plug...
Rented a pressure sensor from Autozone just to check things.
Fuel pressure is around 40...drops to 20 after some time. Guessing one of those injectors is leaking...or the coldstart one which I didnt replace....does not explain why cylinder 5 isnt firing...
Did the ole screwdriver test and it is without a doubt clicking. I reckon I can replace the wires, but the test light shows its firing.
I popped the oil fill lid and checked...I can see the lifters dancing. This is just weird.
These are the old plugs

Found the leak on the filler neck just as yall said. The hole is on the back side...that is why I missed it.

[This message has been edited by Forrest (edited 04-30-2022).]

olejoedad APR 29, 12:08 PM
The injector might be plugged.
Dennis LaGrua APR 29, 12:31 PM

quote
Originally posted by olejoedad:

The injector might be plugged.



My guess as well. Pull that injector and pressure test it. You can purchase an inexpensive test jig that uses a can of carb cleaner to see if it flows. It just might be dirty. There is a cone screen at the top of the fuel injector that can clog but I recommend replacement and not fooling with a 35yr old injector.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

theogre APR 29, 01:04 PM
Could be injector(s) problems...
Could be HEI problems... One iffy plug, plug wire or cap/rotor can cause intermittent problems. Even iffy pickup coil ICM etc can do that.
Worse Both.

Burn oil and/or running way rich often carbons the plugs and carbon basically shorts out the plug trying to fire.

Avoid "Gimmick" plugs even Bosch multi grounds like above. More so if burning oil or running rich.

unplug the tach filter look for miss fires too. Even if you think is fuel problems.
Filter May seem to work but still have problems causing a Soft Short "killing" power to HEI parts or destroy them over time. "Killing" power can actually make power to Stay On part way to I-coil and can I-coil gets abnormal hot and doing odd stuff before it fries.
See my Cave, HE Ignition & Ground "Myth" notes

"water" in the tank doesn't mean constant engine problem.
Water can act like air bubbles and some water gets pump out then return after getting thru injector rail.

FP pickup isn't at the bottom of tank to allow some water in it. Is a "sweat spot" between no water gets pick up to all water and car won't even start. Worse Can be where the car is driven or parked as tank bottom is not level and water level for pump sock changes to be at the "bottom" of tank at any moment.