Automotive Forums .com - the leading automotive community online! Automotive Forums .com - the leading automotive community online!
Automotive Forums .com - the leading automotive community online! 
-
Latest | 0 Rplys
Go Back   Automotive Forums .com Car Chat > Jeep > Grand Cherokee | Grand Cherokee SRT8
Reply Show Printable Version Show Printable Version | Email this Page Email this Page | Subscription Subscribe to this Thread
 
Thread Tools
Old 03-14-2007, 09:41 AM   #1
surf1324
AF Newbie
 
Join Date: Mar 2007
Location: Corpus Christi, Texas
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Loss of power and hesitation during acceleration

I have a '98 Jeep Grand Cherokee that hesitates during acceleration. This problem usually occurs when I first start the vehicle. When this occurs, if I stop the vehicle, it idles funny. It will rev then sounds like it will stall repeatedly until it smoothes out. After it smooths out, it runs fine and with no problems. I have pulled the fuel pump and cleaned the filter that is attached to the fuel pump, I have changed all plugs and wires, and replaced cap and rotor. I also looked for an EGR valve but was unable to find one on this vehicle. When it does bog out, if I give it gas, it leads to (what I believe) is a spark knock. My next step is to check the throttle body. By the way, this vehicle is a strait 6. Any other ideas would be a huge help. Thanks...
surf1324 is offline   Reply With Quote
Old 03-15-2007, 12:05 PM   #2
fredjacksonsan
Caution: Monkeys bite!
 
fredjacksonsan's Avatar
 
Join Date: Apr 2004
Location: near Denver, Colorado
Posts: 10,109
Thanks: 14
Thanked 67 Times in 62 Posts
Send a message via AIM to fredjacksonsan
Re: Loss of power and hesitation during acceleration

Are you getting any codes from the computer? How many miles are on it?

(you can get codes by turning ignition on-off-on-off-on within 5 seconds - without starting - then you'll get the codes flashing on your odometer.)

Check them out and let us know what you find.
__________________
Ours: 2020 Jeep Wrangler 2.0, 53k
2013 Toyota FJ Cruiser, 84k
Kids: 2005 Honda CRV, 228k
fredjacksonsan is offline   Reply With Quote
Old 03-15-2007, 09:58 PM   #3
surf1324
AF Newbie
Thread starter
 
Join Date: Mar 2007
Location: Corpus Christi, Texas
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Loss of power and hesitation during acceleration

Well, I looked for the codes and nothing came up... The vehicle has 84,000 miles on it and runs very good except for the hesitation. (The hesitation only comes up about twice a day, and always after I start it.) It's as if it is not getting the fuel it needs. When I pulled the fuel pump, and disconnected the fuel line, it had plenty of pressure in the line which throws me away from the idea of the fuel pump going out. Any other ideas are greatly appreciated... Thanks...
surf1324 is offline   Reply With Quote
Old 03-16-2007, 06:55 AM   #4
fredjacksonsan
Caution: Monkeys bite!
 
fredjacksonsan's Avatar
 
Join Date: Apr 2004
Location: near Denver, Colorado
Posts: 10,109
Thanks: 14
Thanked 67 Times in 62 Posts
Send a message via AIM to fredjacksonsan
Re: Loss of power and hesitation during acceleration

I'm thinking that since it's only right after startup, when the engine hasn't warmed fully (based on your description) that you could have some carbon build up in the intake that's not letting the sensors adjust to the cold condition. I've seen other posts on the 4.0 liter that a good cleaning of the intake solved rough running or idle issues.
__________________
Ours: 2020 Jeep Wrangler 2.0, 53k
2013 Toyota FJ Cruiser, 84k
Kids: 2005 Honda CRV, 228k
fredjacksonsan is offline   Reply With Quote
Old 03-16-2007, 10:57 AM   #5
surf1324
AF Newbie
Thread starter
 
Join Date: Mar 2007
Location: Corpus Christi, Texas
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Loss of power and hesitation during acceleration

Thanks for the info. I will give it a try and let you know... I'm really reaching for any answer and am willing to try anything. If you think of anything else, please don't hesitate to let me know... Thanks.
surf1324 is offline   Reply With Quote
Old 03-30-2007, 11:30 AM   #6
surf1324
AF Newbie
Thread starter
 
Join Date: Mar 2007
Location: Corpus Christi, Texas
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Angry Re: Loss of power and hesitation during acceleration

I found this post and it sounds like this guy is having the same problem that I am. This description sounds like my jeep to a "T"... I need help...


"I have a problem with my 96 cherokee (130k, 4.0 I6) that seems to stump a lot of gearheads that I know, I'll tell you as many details as needed, hopefully someone has had a similar experience and can help:

When accelerating to cruising speed, ONLY the first time after startup, the engine suddenly bogs in rpm and loses power somewhere between 15-35 mph (sorry, no tach). This power lost can last anywhere from 1 second to 4 or 5 seconds, and only seems to get worse if I press on the gas more. When it does pick back up, it REALLY picks up and I can feel a very noticeable difference in power. As I mentioned, it only does it within seconds of starting the vehicle, and accelerating the first time after startup. When I do accelerate, it make a popping noise from the engine or mabye the air cleaner.

It is fairly sparatic on doing this, not every time, sometimes it can go days without doing it, then sometimes 3 times in a row one day (upon consecutive starts).

Seems to do it whether engine is hot or cold.

Air filter is good.

Fuel filter replaced about 20k ago.

Seems to be independent of fuel level in tank.

Tranny fluid level and color is good, flushed about 30k ago.

New TPS sensor about 35k ago

Any help would be great."


I have exactly the same problem as described in the previous post. Since last posting, I have replaced the TPS, MAP sensor, and IAC valve. I have also pulled the injectors and cleaned the intake and injectors. I have been told to change the fuel filter but it does not make sense to since it only happens once after I start the car. If it was the filter, I would think that it would be a continuous problem instead of a one time thing after starting. Mabye another kind of sensor? I need help, it's driving me crazy. It can be very dangerous when getting on the freeway right after starting the car. I do this sometimes and it just decelerates on me.
surf1324 is offline   Reply With Quote
Old 04-11-2007, 06:51 AM   #7
Jeep79&98
AF Newbie
 
Join Date: Apr 2007
Location: Deep River
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Arrow Re: Loss of power and hesitation during acceleration

Quote:
Originally Posted by surf1324
I found this post and it sounds like this guy is having the same problem that I am. This description sounds like my jeep to a "T"... I need help...


"I have a problem with my 96 cherokee (130k, 4.0 I6) that seems to stump a lot of gearheads that I know, I'll tell you as many details as needed, hopefully someone has had a similar experience and can help:

When accelerating to cruising speed, ONLY the first time after startup, the engine suddenly bogs in rpm and loses power somewhere between 15-35 mph (sorry, no tach). This power lost can last anywhere from 1 second to 4 or 5 seconds, and only seems to get worse if I press on the gas more. When it does pick back up, it REALLY picks up and I can feel a very noticeable difference in power. As I mentioned, it only does it within seconds of starting the vehicle, and accelerating the first time after startup. When I do accelerate, it make a popping noise from the engine or mabye the air cleaner.

It is fairly sparatic on doing this, not every time, sometimes it can go days without doing it, then sometimes 3 times in a row one day (upon consecutive starts).

Seems to do it whether engine is hot or cold.

Air filter is good.

Fuel filter replaced about 20k ago.

Seems to be independent of fuel level in tank.

Tranny fluid level and color is good, flushed about 30k ago.

New TPS sensor about 35k ago

Any help would be great."

I have exactly the same problem as described in the previous post. Since last posting, I have replaced the TPS, MAP sensor, and IAC valve. I have also pulled the injectors and cleaned the intake and injectors. I have been told to change the fuel filter but it does not make sense to since it only happens once after I start the car. If it was the filter, I would think that it would be a continuous problem instead of a one time thing after starting. Mabye another kind of sensor? I need help, it's driving me crazy. It can be very dangerous when getting on the freeway right after starting the car. I do this sometimes and it just decelerates on me.
I Have a 98 jgc and I am having the same problem I cant figure out what is happening I just recently changed the catatlyc Converter and the O2 sensors it improved a little but still hesitating. No codes on the computer Need some Help!
Jeep79&98 is offline   Reply With Quote
Old 04-11-2007, 09:43 AM   #8
sreilly77
AF Enthusiast
 
sreilly77's Avatar
 
Join Date: Nov 2005
Location: Havertown, Pennsylvania
Posts: 545
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Loss of power and hesitation during acceleration

Quote:
Originally Posted by Jeep79&amp View Post
I Have a 98 jgc and I am having the same problem I cant figure out what is happening I just recently changed the catatlyc Converter and the O2 sensors it improved a little but still hesitating. No codes on the computer Need some Help!
had the same problem with my 98 grand cherokee and there was carbon build up. i drizzled SeaFoam down the throttle body and when the engine began to choke i revved it up and tons of grey smoke blew out the back, which is Carbon. after it cleared up it ran great and i got great gas mileage too. but you have to be careful and DRIZZLE SLOWLY down the throttle body until it starts to choke then stop drizzling and rev the engine right there under the hood till it clears up.
__________________
Sean
sreilly77 is offline   Reply With Quote
Old 04-13-2007, 08:05 AM   #9
Jeep79&98
AF Newbie
 
Join Date: Apr 2007
Location: Deep River
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Loss of power and hesitation during acceleration

what do you mean by seafoam?
Jeep79&98 is offline   Reply With Quote
Old 04-13-2007, 04:18 PM   #10
Bob D.
AF Enthusiast
 
Join Date: Nov 2004
Location: LA., California
Posts: 667
Thanks: 0
Thanked 3 Times in 3 Posts
Re: Loss of power and hesitation during acceleration

The only way to properly check the fuel pressure is with a gauge.
On a '98 the ignition on-off-on-off-on method to check for codes does not work, you need to check for codes with a scan tool.
Seafoam is a commercial decarbonizer, water displacement, fuel stabilizer product you can also add to the fuel tank.
Bob D. is offline   Reply With Quote
Old 01-27-2017, 08:04 PM   #11
Newxjowner
AF Newbie
 
Join Date: Jan 2017
Location: Cape coral, Florida
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Loss of power and hesitation during acceleration

Have you checked your fuel injectors. Sounds like you got some gunk there. You can clean them out and it'll probably .
Newxjowner is offline   Reply With Quote
Old 02-07-2017, 10:03 AM   #12
rhandwor
AF Enthusiast
 
Join Date: Sep 2006
Location: Athens, Georgia
Posts: 4,662
Thanks: 0
Thanked 64 Times in 64 Posts
Re: Loss of power and hesitation during acceleration

Quote:
Originally Posted by Jeep79&98 View Post
what do you mean by seafoam?
Napa sells this product.
rhandwor is offline   Reply With Quote
Old 02-07-2017, 10:04 AM   #13
rhandwor
AF Enthusiast
 
Join Date: Sep 2006
Location: Athens, Georgia
Posts: 4,662
Thanks: 0
Thanked 64 Times in 64 Posts
Re: Loss of power and hesitation during acceleration

Auto Zone and Advanced should have a loaner fuel pressure test kit.
rhandwor is offline   Reply With Quote
 
Reply

POST REPLY TO THIS THREAD

Go Back   Automotive Forums .com Car Chat > Jeep > Grand Cherokee | Grand Cherokee SRT8

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 02:39 AM.

Community Participation Guidelines | How to use your User Control Panel

Powered by: vBulletin | Copyright Jelsoft Enterprises Ltd.
 
 
no new posts