Oh boy, engine won't rev.

Post Reply

Topic author
rpjn59
I am merely driving my van
I am merely driving my van
Posts: 23
Joined: Sat Jun 16, 2018 10:51 am
Location: Florida

Oh boy, engine won't rev.

Post by rpjn59 »

Well, I might have really did it! Last night, driving home crossing over a surface road, I had my '04 astro in cruise control. As I went up the relatively unassuming overpass, about have way up, the tranny kicked down to what I thought was 2nd gear and not 3rd. The motor rpm's went way high for many be three seconds ( I mistakenly thought it up shift to third)and as I got to the top of the hill it shut down and all the dash lights came on, I pressed the gas pedal, assuming the engine shut down, and it did, no response. I coast down the back side, find a place to pull off and restart. At first nothing happened, then on second try it fires up. I was maybe 1/4 mile from my exit so I decided to carefully make my way off and back home, another 3/4 mile. After restart I checked the oil pressure gauge, check-pressure up, tap gas pedal, check-engine reved, shift to drive-ok, start down the road and she delays going into second gear. I baby the pedal and she eventually shift to second and third, but with something like seems like reduced power.
I make it home and I'm thing I just tore up the tranny, bullocks. P.s., checked the tranny fluid all good, check under vehicle no signs of a problem.
So, this morning I go to do a little day light inspection, no visual indicators. I take her for a little drive around the neighborhood. Starts right up, however it does not want to rev-up much at all. Oh-crap, engine troubles?
So final scenario-
-won't rev much, I give pedal but not much happens.
-Tranny shifts late to second and then pretty hard.
-eventually shift late to third.
So, what do you guys thing, I'm merely a weekend warrior. I'm currently guessing that the tranny definitely needs a going over and possible rebuild. The engine is maybe out of timing, stretched the timing chain, she doesn't knock at all? When idling, you wouldn't even know anythings wrong except for the oil pressure is now higher than it used to be. prior to the incident, the oil pressure would be a little below 40 lbs at idle and go to a little above 40 when accelerating. Now it's just above 40 at idle and goes quite a bit above that when accelerating.
Thanks in advance,
Just boiling in Florida :cry: Ray
04 Astro
Passenger

Topic author
rpjn59
I am merely driving my van
I am merely driving my van
Posts: 23
Joined: Sat Jun 16, 2018 10:51 am
Location: Florida

Re: Oh boy, engine won't rev.

Post by rpjn59 »

Update, this evening I started her up again and went around the block.
- does start.
- in either park or neutral, it will rev, but then stumbles on the way down to idle and takes maybe 10 sec. to even out.
-in drive with foot on the brake and applying some gas, well it just feels like she's fighting herself and doesn't know what to do.
-trannies about the same as previously described.

Thanks again...
04 Astro
Passenger
User avatar

MountainManJoe
I have my van tatooed on my cheeks
Posts: 3101
Joined: Fri Aug 08, 2008 12:55 pm
Location: The Pacific North Wet
Has thanked: 44 times
Been thanked: 24 times

Re: Oh boy, engine won't rev.

Post by MountainManJoe »

You need to tell us what you're driving. Did the MIL come on?
Lack of power/stumbling can be fuel delivery or ignition. Check fuel pressure and ignition system.

Topic author
rpjn59
I am merely driving my van
I am merely driving my van
Posts: 23
Joined: Sat Jun 16, 2018 10:51 am
Location: Florida

Re: Oh boy, engine won't rev.

Post by rpjn59 »

Hi, thanks for the response. In the OP I mention that it was an 04 astro. Further than that, it is a window van, duel ac, 4.3L, 127K, power locks/windows and cruise control. I bought the van 1 year ago at an auction. It was previously owned by a municipality and assumed that it was likely well maintained.The only thing that I have replaced is parts to repair the ac system and new air filter. The service engine soon light came on at the end of last summer but stopped coming on within a day or two, which I ended up ignoring. The same light came back on yesturday.
-when she revs up she gets there reasonably, but you can tell, not like she should.
-for clarity, the rpms stumble on the way down and takes about 10 secs to settle into a good idle.
-gas mileage is not so good, only been getting between 11- 13 mpg. But 90 percent of my driving is local, so I am assume that's the reason for that.
-it did overheat last week, gauge got ~220, pulled over and it needed 2 gal antifreeze. At that time I noticed that the radiator cap had a gummy goo on the working side. I cleaned it and reinstalled, assuming someone used some kind of stop leak product in the past.
- what is MIL that you referenced?
04 Astro
Passenger
User avatar

MountainManJoe
I have my van tatooed on my cheeks
Posts: 3101
Joined: Fri Aug 08, 2008 12:55 pm
Location: The Pacific North Wet
Has thanked: 44 times
Been thanked: 24 times

Re: Oh boy, engine won't rev.

Post by MountainManJoe »

Google <- great thing.
MIL= Malfunction Indicator Lamp
I can't remember what it looks like on the Astro ... orange engine symbol?

OBD can be a great help. Scan for stored engine codes, make sure sensors are giving good readings, make sure knock retard is OK.

Like I said, the ignitions system would be the first place I look. (dizzy, plugs, wires, cam/crankshaft sensors) It's a weak spot. Especially the distributor cap.

Next the the fuel pressure.

Jumping straight to engine/tranny rebuild makes no sense at all. Start with the low hanging fruit.

Captn. Crunch
I sleep in my van
Posts: 557
Joined: Wed Feb 01, 2012 12:10 pm
Location: southeastern ct
Has thanked: 1 time
Been thanked: 1 time

Re: Oh boy, engine won't rev.

Post by Captn. Crunch »

I tend to agree with timeless on this, I doubt you suffered a major component failure. I would lean more toward computer/sensor issues such as the engine control module which is one item that ties both the engine and tranny together electronically. If you can drive it to a mechanic or an autozone they can scan your computer to look for issues. The fact that you don’t have an SES - service engine soon light or MIL as they are also known seems to indicate my assumption as the vans computer won’t to my knowledge throw a self diagnostic code, it just stops working properly and makes the van operate so poorly you bring it to someone who has the proper scanning equipment to render a proper verdict
Captn. Crunch
"I don't beat my rig-I use it to it's maximum potential"
1994 Safari conversion (sold) and miss'n it!
1999 Safari SLE AWD junked
2003 GMC Safari AWD SLT
cast iron Torsen equipped front diff
S-10 leafs-G80 rear w/3.73’s
2” body lift w/Falken Wildpeak AT’s

Topic author
rpjn59
I am merely driving my van
I am merely driving my van
Posts: 23
Joined: Sat Jun 16, 2018 10:51 am
Location: Florida

Re: Oh boy, engine won't rev.

Post by rpjn59 »

Well, I picked up a Bluedriver bluetooth scan plug-in devise.
The codes that can up was a P0101.
Suggestions were-
-vacuum leak
-PCV valve leak or stuck open. (this was a easy check and the PCV valve has no 'valve' in it whatsoever, I tried plugging the valve cover port with a rag to see it made any difference, it didn't).
-MAF sensor malfunction, everything from bad ground wire, bad MAF wires, bad MAF, dirty MAF./ One thread recommended unplugging the MAF sensor, with the assumption that would 'by pass' it. But that didn't work, she wouldn't even start.
-then there's a shoot load of other suggestions, replace MAP, fuel pump, distributor, 02 sensors, catalytic convertor, ignition parts, aka basic tune up....She is absolutely due for a tune up, but I've been fearing the challenge of getting the freakin rear plugs and wires off, it looks like a knuckle busting, swearing episode and all children will have to leave the neighborhood and hide any dogs or cats.

Second code was for the tranny, P0756. Which was for the 2-3 shift solenoid. I need to look into this more, but I'm hoping that can be worked on and solenoids replaced by dropping the pan.

I've done more digging and reading and two items that seem to come up the most is a MAF and 02 sensor replacements. I'm leaning toward the simply cheap task of cleaning the MAF. The Bluedriver device has a few 'live' scans and I need to see what I can gleam from that, see if I can get a fuel pump reading. The more I deal with this it reminds me of my old econoline with the same symptoms, which ended up being a clogged Catalytic converter. The night that 'finally' went bad, it was glowing red, I'll check that to night.

Thanks for the responses and please by all means keep the ideas flowing, Ray.
04 Astro
Passenger

Topic author
rpjn59
I am merely driving my van
I am merely driving my van
Posts: 23
Joined: Sat Jun 16, 2018 10:51 am
Location: Florida

Re: Oh boy, engine won't rev.

Post by rpjn59 »

Alrighty then, I figured out how to use the live data on the Bluedriver.
- MAP: 6.7 at idle to 10.9 psi at 2200 rpm. (All data, first number is at idle, 600 rpm, second number is at 2200 rpm, the most I can coax out of the engine).
- MAF: 0.9 TO 5.1 LB/MIN.
- ENGINE LOAD: 3.5 TO 22.5 %
- TIMING ADV. AT # 1 CYLINDER: 16.5 TO 34.5°
- FUEL TRIM ( SHORT TERM)
- BANK 1: 7.8 TO 9.4 %
- BANK 2: 3.9 TO 11.7 %
-02 SENSORS:
- Bank 1, sensor 1: 0.065 to 0.875 volts
- Bank 1, sensor 2: 0.705 to 1.27 volts
- Bank 2, sensor 1: 0.055 to 0.865 volts
That's all for now, any comments greatly appreciated, Ray.
04 Astro
Passenger
Post Reply