Car is missing power, runs fine but definately missing power

Tiny
JAZZMAN170
  • MEMBER
  • 1995 EAGLE TALON
  • 2.1L
  • 4 CYL
  • MANUAL
  • 177,000 MILES
No check engine light.
Rebuilt engine head (Cams, lifter's, etc.)
New TPS (Throttle position sensor)
New idle air control
New timing belt
New exhaust manifold (Old one was cracked)
New Wires (Plugs/wires)

I have recently ordered a new fuel pump and 4 re-manufactured fuel injector's. Plan to switch them all into the car as soon as I get it all. Am hoping it increases the car's power if even a little.

Now what I mean by power is if I were to drive my brother's Mitsubishi eclipse with the identical same engine, its got so much more takeoff power and just overall power when full throttling it. Now hop into my car and it doesn't compare at all. The only difference is my brother's car has performance exhaust system and a different computer type, that's it.
I've just started blindly replacing parts in hopes of finding why its missing power. I have had my friend and my brother both drive my car and they both say its definitely missing power and somethings not right.

I really don't know what else to try at this point, im just blindly throwing money around. I do believe the wiring for the Throttle position sensor is faulty and needs to be clipped and rewired or something as my brother put it. It apparently connects/disconnects if its wiggling around too much, however I don't believe it would be causing this power issue to this extent.

Also not sure if its worth mentioning but it backfires just a little bit when just rolling and not pressing gas (Like if im at 4k rpm and stop giving it gas, as its slowly coming back down it sometimes backfires a little). Not nearly as much since I replaced the exhaust manifold, but still does a little.

What are your suggestions on what I could try doing next or what you think it could be?
Do you
have the same problem?
Yes
No
Saturday, October 3rd, 2015 AT 7:05 AM

11 Replies

Tiny
JAZZMAN170
  • MEMBER
I forgot to add in something significant. I can actually feel the power loss once I hit 3k rpm almost always. I'll full throttle it and you can feel its loss of power, its really odd.
Was this
answer
helpful?
Yes
No
Saturday, October 3rd, 2015 AT 7:21 AM
Tiny
KEN
  • ADMIN
Hey Jazzman170,

It sounds like you might have a plugged cat converter, a good way to test it is simply unbolt or cut the exhaust before the cat to see if the car runs any better, here is more information

http://www.2carpros.com/articles/engine-has-low-power-output

Please let me know what you find

Best, Ken
Was this
answer
helpful?
Yes
No
Wednesday, October 7th, 2015 AT 4:05 PM
Tiny
JAZZMAN170
  • MEMBER
I forgot to add on, I have no cat converter on it. It was plugged when I got the car so we took it off and put a test pipe I think its called? Just a straight hollowed out pipe or old cat, so no exhaust is being blocked.
Was this
answer
helpful?
Yes
No
Wednesday, October 7th, 2015 AT 4:27 PM
Tiny
JAZZMAN170
  • MEMBER
Also if I hold the car's RPM at around 2500 or 3000, or any loud RPM really, you can hear it missing a little. Not sure whats causing that with all these new parts.
Was this
answer
helpful?
Yes
No
Wednesday, October 7th, 2015 AT 4:29 PM
Tiny
KEN
  • ADMIN
Hey Jazzman170,

Okay, can we double check the timing belts marks, if you have a cam one tooth off it will cause the problem, also have you checked the fuel pressure or installed that new fuel pump?

Does the "check engine light" come on when the key is in the "ON" position engine not running?

Best, Ken
Was this
answer
helpful?
Yes
No
Thursday, October 8th, 2015 AT 8:32 AM
Tiny
JAZZMAN170
  • MEMBER
The new fuel pump has been installed and had no effect or differences. When my brother turned the key on a few day's ago, he was able to get a code 20 something and 55. The 20 something code came out as air flow sensor and the 55 he couldnt figure out if it was the code for idle air control or end code. If it was idle air control, thats a new sensor I replaced about 5 months ago, so were prety sure its the end code. He told me I should go ahead and replace the air flow sensor just to get it out of the way.

Strange thing is the check engine light is never lit up when the car is on, even for long drives.

As for the timing, ill have to have my friend take a look at it once more to be sure its lined up. He was the one who timed it and has never gotten it wrong before, so im sure thats not the problem but im gonna have him double confirm!

Aside from that, I noticed my car isnt having power issues after 3k rpm anymore after replacing so much of all this stuff, so thats a plus. It would just seem its the lower RPM thats missing power now, and the missing I can hear when holding the RPM's.
Was this
answer
helpful?
Yes
No
Thursday, October 8th, 2015 AT 7:05 PM
Tiny
KEN
  • ADMIN
Hey Jazzman170,

Good to hear we are making headway, please let me know how the timing belt alignment goes,

Best, Ken
Was this
answer
helpful?
Yes
No
Friday, October 9th, 2015 AT 8:03 AM
Tiny
JAZZMAN170
  • MEMBER
You will be glad to know I solved most of the issues now, with the latest fix being the throttle cable. I had my brother rip out all the cruise control and replace it with a straight throttle cable. There was a large vacuum leak under it and we plugged that up. Aside from that, the car is much more responsive now and doesn't stick with the pedal. Everything seems to be working as it should! The only issue I have now is its slightly missing. Nothing to fail smog I wouldn't think, but I don't like my vehicles to have any missing or issues at all, so hopefully the 4x new re-manufactured fuel injector's will help or fix the missing and if not, who know's why its slightly missing haha.
Was this
answer
helpful?
Yes
No
Saturday, October 24th, 2015 AT 5:48 AM
Tiny
KEN
  • ADMIN
Great find! Yep low power? Check it see if its getting full throttle hehe, nice work glad we could be apart of the diagnosis. As far as the missing while at higher rpm's could be coil or spark plug failure.

Best, Ken
Was this
answer
helpful?
Yes
No
Saturday, October 24th, 2015 AT 9:06 AM
Tiny
JAZZMAN170
  • MEMBER
I didnt even think about the coil haha. That could easily be why its missing slightly. I'll have to replace that just so I know its new :P I enjoy having a car with many new parts on it so I know im going to be running strong for ATLEAST a year haha. Could the crankshaft sensor cause a little missing if its going bad or old?
Was this
answer
helpful?
Yes
No
Saturday, October 24th, 2015 AT 5:30 PM
Tiny
KEN
  • ADMIN
O ya, when the CKS gets weak it can break down causing a high RPM misfire.

Here is more info on replacing it

http://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

Let me know how it goes :-)

Best, Ken
Was this
answer
helpful?
Yes
No
Sunday, October 25th, 2015 AT 12:31 PM

Please login or register to post a reply.

Recommended Guides