4g64 Hesitation

[pointblank9957]

My Spyder has a 4g64 and it lags really bad sometimes, i just seafoamed it a few weeks ago. I'm wondering if its dirty injectors?

[pbwu1f]

Just go over the basic stuff. Check oil, coolant, spark plugs, wires, etc. What kind of gas do you guys have up there, what kind do you use? When's the last time you changed the fuel filter?

[pointblank9957]

Originally Posted by pbwu1f

Just go over the basic stuff. Check oil, coolant, spark plugs, wires, etc. What kind of gas do you guys have up there, what kind do you use? When's the last time you changed the fuel filter?

changed oil 2 weeks ago, coolant is full, spark plugs are perfect, wires i'll have to test, we have 87-93 i use 87 but sometimes i'll use 93, and i havent changed a filter yet.

[phunny]

What kind of hesitation? If you are talking about some light throttle hesitation you tps may be out of adjustment.

[pointblank9957]

Originally Posted by phunny

What kind of hesitation? If you are talking about some light throttle hesitation you tps may be out of adjustment.

Like when i start to press the peddle itll sort of bog the more i push it

[1davho]

I would run 91 and change your fuel filter

93, sorry

[sordid]

Check the tps voltage for smooth movement across the range and the ranges are set properly. If there's a deadspot, the voltages jump or are very low (or high), that would cause problems.
If there is a probelm with the TPS, it also may only show when it's heated up by the engine bay temperature. Does it do this when the engine is cold and warm, or just warm or cold?

Originally Posted by 1davho

I would run 91 and change your fuel filter

93, sorry

Changing, or atleast checking, the fuel filter is a good idea. Who knows what kind of sludge is in there.
However, running 93 on a NA 4g64 is quite pointless and a waste of money at the pump. The OP shouldn't need to guard that much against detonation.

[pointblank9957]

Originally Posted by sordid

Check the tps voltage for smooth movement across the range and the ranges are set properly. If there's a deadspot, the voltages jump or are very low (or high), that would cause problems.
If there is a probelm with the TPS, it also may only show when it's heated up by the engine bay temperature. Does it do this when the engine is cold and warm, or just warm or cold?



Changing, or atleast checking, the fuel filter is a good idea. Who knows what kind of sludge is in there.
However, running 93 on a NA 4g64 is quite pointless and a waste of money at the pump. The OP shouldn't need to guard that much against detonation.

It does it Whether its warmed up or not, and when im cruising, (@2500) the rpms will drop and the engine will kind of jerk at around 2000 even with the throttle at the same point as 2500.

[DSMTyson]

Sounds to me like you are running lean. Change your fuel filter asap.

[hotsause64]

yeah its sounds like the tps and considering you said you never changed your fuel filter i would go that route and if that doesnt work come back and ask more questions

[Lou98GSX]

what happens when you floor it does it run good then . if it does then you could have a bad upstream o2 sensor.

[andrewshowers]

You should invest in a wideband, regardless of your mods every dsm should have one.

[boost97gst]

Check fuel pressure and the color of the plugs. See if theyre lean or rich. Thats a poor mans wideband lol.
Dont use 93, obviously...Its a waste of money.
Check air filter
Just basically go through the fuel, spark, and air and see what you come up with. Not too tough to diagnose NA engines.
Changing fuel filter isnt a bad idea either. Cant hurt and its cheap and easy. Just get some crowfoot wrenches, itll make it alot easier to remove if its anything like the gst fuel filter

[tametalon92]

how bout a blt?

[pointblank9957]

Originally Posted by DSMTyson

Sounds to me like you are running lean. Change your fuel filter asap.

wouldnt it bog when its running rich though? you get slightly more power when its leaner

[WES_393]

Originally Posted by pointblank9957

wouldnt it bog when its running rich though? you get slightly more power when its leaner

Lean makes more power to a certain extent. If your running too lean then you get issues with preignition or even fuel starvation. Your also correct that too much fuel can do the same thing. So I would suggest changing the fuel filter as well as the front O2 sensor.

However, since the problem seems intermittent, it sounds like an ignition or electrical problem to me. I'd check the obvious ignition parts such as wires, coil pack, plugs (even if new), etc. Also check the connectors/wires to the Crank and Cam sensor. I'd even check voltage at the battery and alternator while running along with all power/ground wires.