Need Help: engine stalls, truck undrivable

[jmabarone]

Okay, so my calamities continue. After changing the headgasket on the 2.3, I discovered that it was again letting water into #1, so I decided to get a new engine. I picked up a 2.5 from a 2000 with 120k miles.

The 2.5 was a long block swap except for the lower intake manifold, and the cam and crank position sensors. Everything else came from the 2.3 (which was running just fine except the bad head).

The truck will start, and idle very poorly. I can rev the engine up, and it will run fine. As soon as I let off the gas, however, it will stall out. I can try to save it by giving it gas again, but it works only sometimes. When I go to restart, it will turn over without any hint of catching until I start blipping the throttle.

I've change the fuel filter, checked fuel pressure (and it is good), and tried the ICV and TPS from the 2.5...all have had no effect. As I said before, the truck ran fine prior to the swap, it was just eventually going to hydrolock. So, I'm thinking there is that could have suddenly gone bad.

Does anyone have any ideas? I've searched endlessly, and I can't find any culprit. I don't want to take it to a shop mostly because I think they will just throw parts at the truck until it runs.

Thanks,
Jake

 

[Mikel89us]

Check the cam and crank sensors, im not sure how exactly to do that, but it might solve your issue.

 

[jmabarone]

Check the cam and crank sensors, im not sure how exactly to do that, but it might solve your issue.

I certainly will. The only reason I haven't yet is because it doesn't throw any codes, and it will run just fine from 1500-5500 rpm if I want to...

 

[Earl43P]

Since you already tried an IAC, I suspect a vacuum leak.

http://www.therangerstation.com/Magazine/Summer2003/VacuumLeaks.shtml

 

[one1]

Last week I was getting water in #2 from a crack in the head and got mine completely rebuilt for $275 with 2 yr wty. Took me two days of waiting and 5 hours to do the actual swap and install it back on. Much better route than an unfamiliar engine.

Is there anything at all about the 2.3 versus the 2.5 you put in that is incompatible electrically in such a way it may have a different crank and cam sensor? You say it won't try to start until you hit the throttle and I suspect that is not fuel related, but electrical with the TPS or something to that effect.

 

[FireFighter431]

Would you need to reflash the computer for a different motor? Or just reset it and let it relearn its parameters? Just throwing out ideas.


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[Mikel89us]

My dad has a 2.5 in his 97, runs great. We have not tuned (reflashed) it at all, so thts not the issue.

 

[zekew64]

I'm thinking the timing isn't right, being off a tooth or having a stretched belt.

Second, I'm thinking that it's actually a MAF/MAP sensor that's bad. Failing that, it's something with the spark plugs (old or fouled somehow), wires, bad ignition coils, injectors, or even your PCV valve.

I mention all this because it's either not getting spark or air--all told, it seems to me that the engine isn't "breathing" properly somehow, as in, it's being starved of either air or spark.

Lastly, check your air filter--it's just as important as your fuel filter, and if it's clogged, it may be starving enough air where the engine can't idle properly.

 

[jmabarone]

I'm thinking the timing isn't right, being off a tooth or having a stretched belt.

Second, I'm thinking that it's actually a MAF/MAP sensor that's bad. Failing that, it's something with the spark plugs (old or fouled somehow), wires, bad ignition coils, injectors, or even your PCV valve.

I mention all this because it's either not getting spark or air--all told, it seems to me that the engine isn't "breathing" properly somehow, as in, it's being starved of either air or spark.

Lastly, check your air filter--it's just as important as your fuel filter, and if it's clogged, it may be starving enough air where the engine can't idle properly.

Spark plugs and wires are less than 50 miles old, air filter is maybe 10 miles old.

I checked the timing marks and they are correct. At this point, I'm going to swap lower intake manifolds and check the cam position sensor wires. They were exposed, so I threw some tape on them to protect them...maybe they are shorting out now.

Thanks guys, keep it coming if you have any other ideas.
Jake

 

[jmabarone]

Update:

I checked the timing marks and they were all correct. I pulled the injectors, and they are all clean. I checked the manifold for any blockages, again, clean. So I buttoned it back up, put the original (2.3) throttle body, TPS, and ICV back on. Now, it will not start even when I pump the gas pedal or hold it wide open.

SO, I'm thinking my crank position sensor must be bad.

 

[jmabarone]

Update:

Truck still not running well.

Swapped crank position sensor and it made no difference.

It will sometimes start, and idle poorly...like it is missing. I let it run and unplugged the following:
MAF- it ran slightly better, but still poorly
Air Temp sensor- no difference
TPS- ran a little better, but still poorly
ICV- it died, which makes sense

I did have a couple plug wires swapped (my book has it wrong...), so I fixed it, and it ran a little better, but still has a miss and will eventually die.

Could I have bad gas or something like that? There's only 1/4 tank, so I may just drain it and put in some fresh gas.

 

[Surrey]

This swap was done recently right? Typically it takes a while of sitting or something getting into the gas tank to foul up your gas.... You said it was running fine before switching engines, have you had it running enough to put more gas in it since, or is it the same gas that was running perfectly fine in your other engine?

 

[jmabarone]

This swap was done recently right? Typically it takes a while of sitting or something getting into the gas tank to foul up your gas.... You said it was running fine before switching engines, have you had it running enough to put more gas in it since, or is it the same gas that was running perfectly fine in your other engine?

it is the same gas. At this point, it has been off the road for at least 6 months. the majority of that time, it has been in a garage.