Sputtering Issue

[gorillaguy8]

My 87 N/A is sputtering and i think its an electrical issue. While im driving, in any gear, the car sputters when it is under "load" with the tranny. The sputtering only happens under 2000 RPM's and when it gets above 2k RPM it goes away and accelerates normally. If the I have the clutch shoved in and i rev the engine the problem does not appear. I have replaced the spark plug wires and the problem went away for about 20-25 mins of driving time, thats why I am convinced it is a electrical issue Anybody ever heard of something like this or have some advice?

[Green7mgte]

sounds like a bad fuel pump not putting out enough pressure at low rpms.

thread in the mk3 section were parts of it discuss a bad fuel pump possibility.
Quote:
Originally Posted by cre
Tyr placing a jumper across FP and B+ in the diagnostic box in the engine bay and then try to start. This bypasses a couple relays and powers the fuel pump directly... it'll help eliminate a bad pump as a possibility.

http://www.toyota-supra.info/forums/...-question.html

Engine error code page from TSRM
http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx

if not check timing or tps
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[gorillaguy8]

If it is the fuel pump, why would replacing the plug wires make the problem temporarily go away? This is the reason that im convinced that its an ignition problem.

I have an MSD ignition coil on the car, My thought was to put the original coil back on the car and see if the problem went away permanently (or at least for a couple days compared to 25 mins). Then if it does fix the problem, get a new performance coil. Anybody, ideas?

[kamikazemkiii]

possibly fowling out the plugs?? could you get a sound clip

[gorillaguy8]

I dont have any recording equipment but i can try and describe it a little. Its not like its running out of fuel and at a random pace. Its steady, like the spark is just real weak. RPMs dont fluctuate, they stay constant. When i accelerate the motor does it slowly but at a steady rate. But once it reaches 2000 RPMs acceleration returns to normal.

[supradaddy0803]

I would see how long it has been since the fuel filter has been changed. As for the plugs fouling easiest way to find out is to pull them and look at them. The color of the electrode end will tell you all kinds of things. But from what your describing sounds like a fuel issue that why he said that. At low RPM's the fuel pump is pushing but only just a little to keep the pressure up. when you rev it and it clears up the fuel pump is working harder to push more fuel through the filter thus giving you enough gas to run right. You have to remember the pump does what the computer tells it to. My car when it had the 7MGE in it did the same thing I changed the filter problem went poof. Also check your ignition timing. It may be that your distributor is off a tooth and the car cant spark advance it far enough to run properly at idle. All I am saying is do the cheap stuff first. Pulling the distributor and putting it back properly takes like 10 minutes. Fuel Filter is like 15 bucks and takes about 15 Minutes to change. If you think your coil isnt working properly there is a test for it.