acts like it wants to stall
#91
09-24-2014, 04:03 PM
Doc, you forgot 1. Put it wherever you want.
Check to see if ALL of your intake manifold fasteners are tight. Several have found this to be their issue with rough idle/almost stalling at idle. Along with a good TB cleaning!
Check to see if ALL of your intake manifold fasteners are tight. Several have found this to be their issue with rough idle/almost stalling at idle. Along with a good TB cleaning!
#92
09-24-2014, 04:46 PM
Those bolts get tightened after the cyl. head is installed, so the customer that just paid for cyl head removal, has NO idea what really fixed it.
There are to many mechanics out there that don't know how to diagnose and follow a flow chart, instead, always want to jump to the worst case scenario!
NOT under my watch.
On a side note, when a leak down test shows a valve not seating properly, I perform an induction cleaning first, worked on my rig, and many of my customer's vehicles.
#93
09-24-2014, 05:02 PM
False stall, rough idle with no check engine light 3.5L L52 or 3.7L LLR:
1) Clean the TB with TB cleaner only.... there are multiple threads on this, the best way to do it is remove it, clean it, re-install it;
2) Clean the MAF sensor using MAF cleaner only... there are multiple threads on this (might as well while you have the intake apart to clean the TB);
3) inspect the coil on plug packs and their connectors to the wire harness and any obvious signs of corrosion from water on top of the head.
If the problem still persists, and you have more than 70K miles (plugs should go damn near every bit of 100K in the trucks). If you do not have more than 70K miles, skip to #6 or feel free to change plugs for the sport of it:
4) change the spark plugs and inspect them for evidence of any fouling;
5) while the plugs are out, look closely at the plug on coil packs to see if there is internal corrosion, if so clean them with electrical cleaner spray and allow to dry before placing them back on the plugs.
If the problem still persists:
6) Pull the camshaft position sensor and look for crud on the sensor, on the screen in the motor, or a missing screen... replace if necessary.
If the problem still persists:
7) then do a compression test.
Watch the temp gauge, better yet get a scanner an observe actual operation temp. If that is lower than normal, consider a T Stat replacement.
1) Clean the TB with TB cleaner only.... there are multiple threads on this, the best way to do it is remove it, clean it, re-install it;
2) Clean the MAF sensor using MAF cleaner only... there are multiple threads on this (might as well while you have the intake apart to clean the TB);
3) inspect the coil on plug packs and their connectors to the wire harness and any obvious signs of corrosion from water on top of the head.
If the problem still persists, and you have more than 70K miles (plugs should go damn near every bit of 100K in the trucks). If you do not have more than 70K miles, skip to #6 or feel free to change plugs for the sport of it:
4) change the spark plugs and inspect them for evidence of any fouling;
5) while the plugs are out, look closely at the plug on coil packs to see if there is internal corrosion, if so clean them with electrical cleaner spray and allow to dry before placing them back on the plugs.
If the problem still persists:
6) Pull the camshaft position sensor and look for crud on the sensor, on the screen in the motor, or a missing screen... replace if necessary.
If the problem still persists:
7) then do a compression test.
Watch the temp gauge, better yet get a scanner an observe actual operation temp. If that is lower than normal, consider a T Stat replacement.
Hey Doc ... sounds so much better coming from your mouth, how about making this a sticky.
#95
09-25-2014, 08:35 AM
False stall (acts like it wants to stall), rough idle with no check engine light 3.5L L52 or 3.7L LLR:
1) Clean the TB with TB cleaner only.... there are multiple threads on this, the best way to do it is remove it, clean it, re-install it;
2) Clean the MAF sensor using MAF cleaner only... there are multiple threads on this (might as well while you have the intake apart to clean the TB);
3) inspect the coil on plug packs and their connectors to the wire harness and any obvious signs of corrosion from water on top of the head;
3.5) Check to see if ALL of your intake manifold fasteners are tight (they do vibrate loose on occasion) to 10 N.m/89 lb in.
If the problem still persists, and you have more than 70K miles (plugs should go damn near every bit of 100K in these trucks). If you do not have more than 70K miles, skip to #6 or feel free to change plugs for the sport of it:
4) change the spark plugs and inspect them for evidence of any fouling;
5) while the plugs are out, look closely at the plug on coil packs to see if there is internal corrosion, if so clean them with electrical cleaner spray and allow to dry before placing them back on the plugs.
If the problem still persists:
6) Pull the camshaft position sensor and look for crud on the sensor, on the screen in the motor, or a missing screen... replace if necessary, tighten mounting bolt to 10 N.m/89 lb in.
If the problem still persists:
7) Then do a compression test, a normal read would be appx 1482 kPa/215 PSI. You can follow that with a leak down test. According to Hummerz when a leak down test shows a valve not seating properly, he performs an induction cleaning first, worked on his rig, and many of his customer's vehicles.
Watch the temp gauge, better yet get a scanner an observe actual operation temp. If that is lower than normal, or coolant is low (like at the 1/2 level) consider a T Stat replacement.
1) Clean the TB with TB cleaner only.... there are multiple threads on this, the best way to do it is remove it, clean it, re-install it;
2) Clean the MAF sensor using MAF cleaner only... there are multiple threads on this (might as well while you have the intake apart to clean the TB);
3) inspect the coil on plug packs and their connectors to the wire harness and any obvious signs of corrosion from water on top of the head;
3.5) Check to see if ALL of your intake manifold fasteners are tight (they do vibrate loose on occasion) to 10 N.m/89 lb in.
If the problem still persists, and you have more than 70K miles (plugs should go damn near every bit of 100K in these trucks). If you do not have more than 70K miles, skip to #6 or feel free to change plugs for the sport of it:
4) change the spark plugs and inspect them for evidence of any fouling;
5) while the plugs are out, look closely at the plug on coil packs to see if there is internal corrosion, if so clean them with electrical cleaner spray and allow to dry before placing them back on the plugs.
If the problem still persists:
6) Pull the camshaft position sensor and look for crud on the sensor, on the screen in the motor, or a missing screen... replace if necessary, tighten mounting bolt to 10 N.m/89 lb in.
If the problem still persists:
7) Then do a compression test, a normal read would be appx 1482 kPa/215 PSI. You can follow that with a leak down test. According to Hummerz when a leak down test shows a valve not seating properly, he performs an induction cleaning first, worked on his rig, and many of his customer's vehicles.
Watch the temp gauge, better yet get a scanner an observe actual operation temp. If that is lower than normal, or coolant is low (like at the 1/2 level) consider a T Stat replacement.
#96
09-25-2014, 06:17 PM
I went back and edited my protocol list, I intend to throw it in the FAQ (good suggestion FourXFour), but before I do I want to see if anyone else comes up with important info to include. I think we covered it. Then I will lock this old dog and we can point peeps to the FAQ when needed.
#97
04-01-2017, 01:57 PM
Question
My 2007 H3 has had the same issue that everyone else described. I have talked with numerous people about it and everyone has a different idea of what is causing the problem. Well this weekend I decided to tear into the H3 and take a look for myself.
The solution that fixed it, CLEAN THE THROTTLE BODY BACK TO ITS ORIGINAL ALUMINUM FINISH INSIDE.
Yes that's it, that is all that it took.
Tools required: PH Screw driver, 10MM Socket with extension, carb cleaner and some clean rags.
The inside of my throttle body had a slight brownish/yellow/black grime on the inside. I removed the throttle body and sprayed the inside with carb/throttle body cleaner used a CLEAN rag to remove all of the grime, put it back together and it runs like new.
When I first started the engine it rev'd a little after a short trip down the road the thing ran like new.
It runs like it did the day I bought it. Hope this helps someone else!
The solution that fixed it, CLEAN THE THROTTLE BODY BACK TO ITS ORIGINAL ALUMINUM FINISH INSIDE.
Yes that's it, that is all that it took.
Tools required: PH Screw driver, 10MM Socket with extension, carb cleaner and some clean rags.
The inside of my throttle body had a slight brownish/yellow/black grime on the inside. I removed the throttle body and sprayed the inside with carb/throttle body cleaner used a CLEAN rag to remove all of the grime, put it back together and it runs like new.
When I first started the engine it rev'd a little after a short trip down the road the thing ran like new.
It runs like it did the day I bought it. Hope this helps someone else!
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