bad stumble/miss

[foxmxrcer]

Hey guys, long time since ive been on here or even messed with a TD :mad: ....so anyways, car is an 87 dodge daytona shelby z, 2.2 common block bored .20 over H beam rods, 3" SV 3" exhaust big FMIC 52mm tb, MP st2 comp, and a rising rate FPR, walbro 255 pump, 1yr old fuel filter along with some other goodies. But anyways, Car had overheating issues a few years back and I could never figure out why, which led to me parking it and letting it sit. Well last week I decided to do the head gasket on it (was the last idea I had to fix it) and I went out behind the shop to start it up, and it would crank but not start, and hit hard spots (like timing to advanced) it would sputter ever once in a while and then it would finally start and run for 5 seconds or so then shut off, so I just said screw it and pushed it in. Did the head gasket, turns out it did have a leak in the coolant jacket to the cylinder under the fire ring. got it all back together, and it did the same thing, no start, would spit and sputter and sometimes run for 5 seconds but then die again. Lost hope for the day and went home, then the next day I played with the ign timing a bit, made no difference, then I got my co worker to look at it, he ----ed with the ign timing also and it fired up! (magic touch?) anyways, idles fine and starts right up now, timing is set to 12* and the cam timing is dead on, fuel pressure is ~56 satic and AFR is correct at idle. Now, the current problem, When ever I try to drive it it misses and stumbles ("machine gun missfire") and has absolutely no power, I looked at my AFR (wideband) gauge and its burried in lean, this happens at a cruise, and WOT, and well, all the time if im on the throttle. The thing I dont understand is 2-3 months ago I took it out for a drive around town and it was fine (aside from running warm), parked it, then this all started? Any input would be nice and helpful. Oh, and the fuel in it is premium but its anywhere from 2-6 months old (i cant remember when i filled it up last)

Thanks, Jake

[RoadWarrior222]

My crystal ball is saying, "Check for intake and exhaust restrictions, lucky number 57, beware of the color blue"

[foxmxrcer]

where did you get your crystal ball? the matco and snapon guy here never have one in stock, or a magic wand for that matter..... but anyways, intake and exhaust are all clear, throttle body is as clean as new and polishd up (few hundred miles ago)

[Rrider]

There have been a few people with in-tank type issues lately. Melted hoses and blown out relief valves and such. I'm betting on that.

[RoadWarrior222]

It's an EPIDEMIC!!!!!:bolt:


Yah, could hook up a gauge, see if your fuel pressure starts fluttering when it does it.

---------- Post added at 01:48 PM ---------- Previous post was at 01:44 PM ----------


where did you get your crystal ball?Gypsy Lee's Discount Tool Mart and Daycare.... in the converted Fry Wagon on the corner of 5th and Main.

[foxmxrcer]

ill have to check that store later today, maybe they have a magic wand haha, I dont understand how that could of happened just sitting, but ill look into it, n the meantime, does anyone else have any ideas?

[turbovanman²]

Codes? Check fuel pressure and monitor while driving. The supplied intank pump hose is garbage. See this thread-

http://www.turbo-mopar.com/forums/showthread.php?66647-Important-fuel-pump-replacement-tip!!!

[foxmxrcer]

forgot to mention that, no codes, and the fuel pressure gauge i have i can not monitor while driving, need a longer hose, but will see if I can dig something up, and if i remember correctly, the hose in the tank was replaced with the one supplied by walbro

[turbovanman²]

forgot to mention that, no codes, and the fuel pressure gauge i have i can not monitor while driving, need a longer hose, but will see if I can dig something up, and if i remember correctly, the hose in the tank was replaced with the one supplied by walbro

That hose is hit and miss.

[black86glhs]

That hose is hit and miss.

Yeah the one that came with my walbro was not rated for in tank use (30R9) instead of the 30R10 line. Don't trust it just because it came in the kit. And sitting seems to kill it just as fast.

[tryingbe]

30R9 hose used, with wrong hose clamps.

http://www.thelostartof.net/tryingbe/dodge/CSX/fuelpumpmess/IMG_6638.JPG
http://www.thelostartof.net/tryingbe/dodge/CSX/fuelpumpmess/IMG_6639.JPG
http://www.thelostartof.net/tryingbe/dodge/CSX/fuelpumpmess/IMG_6641.JPG
http://www.thelostartof.net/tryingbe/dodge/CSX/fuelpumpmess/IMG_6643.JPG
http://www.thelostartof.net/tryingbe/dodge/CSX/fuelpumpmess/IMG_6645.JPG

[Force Fed Mopar]

I'm betting on a fuel pump/delivery problem also.

[87glhs]

Check to see if you have any slop/looseness on the metal rotor that sits under the mag pickup in your distributer. Had a similar issue with my wife's GLHS, which also sat for awhile.

http://i321.photobucket.com/albums/nn379/87glhs/trans_mistake_4.jpg

The metal rotor is the encoder for the IGN system and should be absolutely tight. Hers was causing a problem once the engine warmed up a bit and it started floating around.

You might also look for GND/elex issues. People were famous for pulling the plastic bag/sealant off of their Logic Modules over the years and the two big connectors on top are prone to corrode if they get damp.

Good luck!



Hey guys, long time since ive been on here or even messed with a TD :mad: ....so anyways, car is an 87 dodge daytona shelby z, 2.2 common block bored .20 over H beam rods, 3" SV 3" exhaust big FMIC 52mm tb, MP st2 comp, and a rising rate FPR, walbro 255 pump, 1yr old fuel filter along with some other goodies. But anyways, Car had overheating issues a few years back and I could never figure out why, which led to me parking it and letting it sit. Well last week I decided to do the head gasket on it (was the last idea I had to fix it) and I went out behind the shop to start it up, and it would crank but not start, and hit hard spots (like timing to advanced) it would sputter ever once in a while and then it would finally start and run for 5 seconds or so then shut off, so I just said screw it and pushed it in. Did the head gasket, turns out it did have a leak in the coolant jacket to the cylinder under the fire ring. got it all back together, and it did the same thing, no start, would spit and sputter and sometimes run for 5 seconds but then die again. Lost hope for the day and went home, then the next day I played with the ign timing a bit, made no difference, then I got my co worker to look at it, he ----ed with the ign timing also and it fired up! (magic touch?) anyways, idles fine and starts right up now, timing is set to 12* and the cam timing is dead on, fuel pressure is ~56 satic and AFR is correct at idle. Now, the current problem, When ever I try to drive it it misses and stumbles ("machine gun missfire") and has absolutely no power, I looked at my AFR (wideband) gauge and its burried in lean, this happens at a cruise, and WOT, and well, all the time if im on the throttle. The thing I dont understand is 2-3 months ago I took it out for a drive around town and it was fine (aside from running warm), parked it, then this all started? Any input would be nice and helpful. Oh, and the fuel in it is premium but its anywhere from 2-6 months old (i cant remember when i filled it up last)

Thanks, Jake

[foxmxrcer]

the hall effect window rotor is tight, the dist shaft does however have some play (nothing horrible) when I first got the car the hall effect sensor went out (I was 15, didnt know much about cars at that time) and it ran me around in circles for a week until i figured it out, so due to habbit thats the first t hing I always check now haha. The logic module is still bagged(actually, rebagged when I put the stg2 MP comp in it). Im going to try and get the pump ripped out today while im at work, or tomorrow, or sunday....soon

[foxmxrcer]

just pulled the pump, has a 30r10 hose on it, in good condition, no pulsator disc thing on it either. now, any other ideas?

[turbovanman²]

Do this-


First off, hook up a pressure gauge to the shrader valve or tee in at the rubber line-engine cool and engine off.

Start the car and note fuel pressure, it should be around 50 or a bit less, unhook the vacuum line to the reg and it should go up to 55 psi. Now shut the car off and watch the fuel gauge, the pressure should stay. If not, pinch the return line-if it drops, you have a bad FPR or leaking injectors, if it holds, pinch the pressure line, if it holds, the check valve the in fuel pump is bad and the pump should be replaced.

Make sure the key is off, jump 12 volts to the coil + terminal, a fused jumper wire is best but a piece of wire will work just fine.

Now, you should be reading around 55 psi, now squeeze the return line, the pressure should jump to around 90-100 psi. If not, the pump is no good. You can check the FPR if you have a vacuum pump if not, the above test works.

These tests assume you have no leaks and a clean/newish fuel filter thats not plugged up.

If you have an amp clamp and a lab scope, you can check the brushs by looking at the waveform pattern, it should look like a nice sine wave.

[glhs571]

My car had a similar problem last summer.i swapped out the injectors, FPR, replaced fuel filter, coil, TPS, etc.....it ended up being the plug wires and the cap. Moral of story: always check the easy things first.