Car hesitates/bogs

[Deadly BlaZe]

So yeah, my car just recently started hesitating and bogging. It definitely happens when I'm boosting, and I'm not sure if it does it when I'm not boosting because you can't really feel any power anyway unless your boosting. It does it only occasionally, not all the time, but the majority of the time. I've searched for this problem, and I'm posting this thread basically as a check list of all possibilities. Here are the possibilities I've thought of:

Spark plugs - Just replaced these a month ago, and the car ran fine until now.
Timing - Just had this done properly a couple months ago and the car ran fine until now.
Spark Plug Wires
Fuel Filter
Boost Leak
Bad Turbo

My question is, what other things could there be that would cause this to happen?

 

[phillabaum03]

whats your boost gauge reading vacuum at? TPS sensor, MAF sensor...

 

[50trimmed1g]

Boost leak!

 

[Deadly BlaZe]

whats your boost gauge reading vacuum at? TPS sensor, MAF sensor...

Vacuum reading is at 18-20 inhg, which is correct I think. And it doesn't jump up and down, and Idle is steady. I'll keep the tps and maf sensor in mind. Any one else have ideas?

 

[saechao04]

I would say try wires, fuel filter and I definitely think its boost leak.

 

[90laserRSfwd]

Def. sounds like a boost / vacuum issue

 

[AWDTSIer]

I just went through the same problem, try a boost leak test, it works magic! I found 5 leaks on my car, the major ones where the throttle body gaskets. The others were the j-pipe, bliss screw, and the thermal vacuum valve. Good Luck.

 

[twistedimage03]

I just had the same problem as well car idled great but under boost would spit and sputter and wouldnt be able to hold more then about 5 pounds of boost. Before you go spending money and other things spend about 15 bucks make yourself a good boost leak tester and go from there. more then likely that is your problem.

 

[habitatguy187]

If none of those work it could be a clogged catalytic converter, happened to me on my old lumina. Could even be your knock sensor (kind of feels like fuel cut but not that bad). But def. start with a boost leak test, that's probably the problem.

 

[Deadly BlaZe]

Thanks for the replies guys. I'll keep all that in mind.

I just had the same problem as well car idled great but under boost would spit and sputter and wouldnt be able to hold more then about 5 pounds of boost.

Mine wouldn't be quite that bad I think. My car builds 15lbs by around 3.2k rpm. A little late, so it's possibly a boost leak.

 

[Sam@RRE]

dying knock sensor since you say it happens sometimes and sometimes it doesn't.

 

[Deadly BlaZe]

dying knock sensor since you say it happens sometimes and sometimes it doesn't.

Oh..but then again, it would only happen sometimes with all the other possibilities (fuel filter, plug wires, boost leaks, etc) too right?

 

[eibomz]

Check the wires and plugs. They are relatively cheap, and easy to get to... I have had issues that sounds identical to that and it was my spark plug wires. The bogging for me was when my engine kept missing loads. Good luck!

 

[Deadly BlaZe]

Just thought I'd update this thread. I seem to have found the problem. My coolant light came on today, so I was running low on coolant. I filled it up, and miraculously the hesitation stopped. I guess cause it was getting hotter than usual under the hood, it caused the ecu to pull timing?

 

[jerry_69]

No one thinks about the intercooler. I had no boost for a while, couldn't figure out where the leak was at. I searched and changed fuel filter, wires etc, and still nothing. Turns out to be that my intercooler had a crack about 1/2 inch wide about 6 inch long so go figure. If I was you just give it a check, take it off and make sure its good. Just putting in my t2o cents...

 

[Deadly BlaZe]

No one thinks about the intercooler. I had no boost for a while, couldn't figure out where the leak was at. I searched and changed fuel filter, wires etc, and still nothing. Turns out to be that my intercooler had a crack about 1/2 inch wide about 6 inch long so go figure. If I was you just give it a check, take it off and make sure its good. Just putting in my t2o cents...

Lol look above, already solved the issue.

 

[noob-e]

I am having the same problem with my car. It has been going on for over a year or 2, but has recently gotten worse. I have checked for boost leakes and all I found were some little ones at the throttle body spacers. I got some new spacers, but never got aroud to installing them until a few weeks ago. I took out the throttle body and replaced the spacers - and put on 2 new gaskets (1 engine side and 1 intake side). I hooked everything back up and my car ran like a beauty........for about 2 days. I can't remember my car being that fast since I bought it. However, the problems gradually got back to their previous state. The car now acts like it did before the throttle body rebuild. I tested my plugs and wires and they seem ok. (I have changed these items in the past and they never really helped).


So - I decided to change my own fuel filter....BIG mistake. I bent the bottom fuel line and ended up having to order one of those cool STM fuel filter kits with the braided hoses and everything

Anyways, I am now waiting on the parts to arrive - and while waiting I have re-wired my fuel pump and ordered some wire to do the 'home-made grounding kit'. So, if I still have the problem after replacing my fuel lines/filter, then what is the nest step? I checked my compression and it was pretty good across the board (I don't recall the exact numbers). I have new plugs and wires on-hand, in case I need them, but I don't think they are the problem.

It's just wierd that the problem basically went away for 2 days after I rebuilt the throttle body, but then just came back (not any worse than before, but not any better either).

I have checked for boost leaks all over the car, including the intercooler and I have none!

How can you check things like the knock sensor, etc? Wouldn't that kind of thing throw a CEL?

FYI - The car is totally stock, except for the stereo system - timing belt has not been replaced that I know of and the car just hit 100k miles (97 GSX)

 

[DeNoZZo]

I heard a bad ground can cause that to happen. I can't remember where, but I remember reading that somewhere. Doesn't really make any sense that would cause that problem, but it's something to check.

 

[noob-e]

It's really funny that you mention that because my battery has 2 stock cables on the neg terminal - one going to the firewall, then another one.....which was not connected to anything . I didn't even notice this until I took the battery out, in order to get to the fuel filter 2 weeks ago. I heard that this cable was supposed to be grounded to the block or the transmission housing, but I am not where where. I see an open screw hole down in that general area, but I can't be sure - in anycase, I guess it doesn't matter since I am doing the grouding upgrade thingy and will be replacing all grounds.

I also wanted to replace the positive wiring from the battery, just for the sake of cleaning it up with some new wiring, etc. However, here is my quesitons for the electrical gurus....There are 2 things coming from the positive terminal on my car - One is a big wire (1 or 2 gauge) and then there are a series of smaller wires (maybe 8 guage) that come from the fuse box. I followed the series of smaller wires and then leave the fuse box and go under the radiator, around to the red cap on the alternator. The other wire runs behind the block - to a plac that I can reach, but can't actually get a good look at. Is this wire attached to the starter? Any suggestions?