Engine sputtering when under a load (long).

This has been a real frustrating problem.

It sputters or misses under load, any gear and any rpm range without any boost. I can drive it like a little old lady and it's okay, but what's the point in owning the car if I have to do that all the time?

I've checked or replaced the following:

*fuel pressure 43 psi at idle and hose disconnected. It's a Walbro 255lph and less than 2 years old.
*new motorcraft wires, cap, and rotor.
*motorcraft plugs looked like new, .032 gap.
*new tps set at .95 volts.
*new coil.
*swapped out the injectors with another set, but no change.
*cleaned out the throttle body and egr passage, which was very dirty.
*checked all over for vacumm leaks.
*checked the intercooler hoses and clamps.
*checked timing, it was 12 btc.
*checked codes and had a 74 and 77, it has always run rich at idle.
*did a compression check and the range was 140 to 155.
*took valve cover off and inpected valve components.
*retorqued the head bolts, but they seemed fine.


Things I haven't done:
*check fuel pressure while driving.
*check voltage to coil while driving.
*replace the TFI and/or PIP.
*dropped gas tank to inspect fuel pump, sock and screen.
*swap main ecu with another one.


So what should I try next?

I've read that a lot of people have had similar problems but only at higher rpms and with boost.

Is it still possible that my head gasket is on the way out? I usually never even get to 18psi, but it has been that high. I have a Felpro 1035 so maybe it is leaking, but not totally blown out?

Any advice is very welcome at this point.

Thanks!



------------------
'88 TC 5sp, K&N cone, t3.60/.48, ported head, Felpro 1035, Walbro 255 hi pres.

I would guess, do the fuel pressure while driving. That would eliminate the fuel system until you get to the fuel rail. Fuel filter??

I'll send you some info on testing the TFI/PIP. Also check the connections and wiring for same.

Pull the distributor and check for gear wear and side play in the shaft.

Thanks Pete.

I knew I was forgetting some of the things things I had done.

Yes, I did the fuel filter too.

I do have a spare TFI to test it with. I even have a extra distributor but it is from a merkur.

------------------
'88 TC 5sp, K&N cone, t3.60/.48, ported head, Felpro 1035, Walbro 255 hi pres., Kirban FPR.

The distributor from a Merkur will work.

Check your IC hoses and make sure 'MAKE SURE' they are tight and not leaking or torn. I changed almost the entire ignition system befor finding my connections were loose enough to let air escape under boost.
Believe me, the computer wants to know what happened to that air!

------------------
Steve Wagner
Nato member
87TC auto(stock)
88TC, 5 speed, StageII Star clutch w/ StageIII pressure plate,lightened flywheel, K&N in fender, gillis valve, 255lph Walbro, Kirban adj.FPR,Bypass valve, 3" exhaust from turbo to tip (high flow cat/ Magnaflow muffler), A-pillar gauges(A/F & Boost), 16" ARE 5 spoke wheels 7" front 8" rear(225/50VR16 / 245/50VR16 Yokos'). Subframe connectors

It's finally fixed!!!

I feel really stupid after finally finding the problem. I had the intercooler off (again) and checked the hose going to the wga. It was a bit loose so I clipped about an inch off and tightened it up.

Fixed!

Lesson learned - don't forget the bottom hose when it sputters.

Best part is it really runs better than ever with all the recent attention to everything.

Now I need to replace the smoking turbo. Funny how problems come in groups.

------------------
'88 TC 5sp, K&N cone, t3.60/.48, ported head, Felpro 1035, Walbro 255 hi pres., Kirban FPR.