Swapped 89 2.3 to 95 2.3 truck doesn't run right

[JoshErnst1074]

So I swapped an 89 2.3 to a 95 2.3. The guy said it would work. Turns out I had to swap all the pulleys and the power steering from the old motor over so the serpentine belt would fit right. Started the truck up, it purred. Ran perfect for about 3 hours. Then the brake booster check valve broke off so I had no brakes. Had to duct tape the vacuum hose back in to get home until I bought another check valve. Halfway home the engine started sputtering and lacked power. If I didn't keep on the throttle the truck would die while rolling. I replaced the check valve the next morning, thinking the brake booster was causing a vacuum leak I assumed the engine would run normal now. Not the case. It's backfiring, won't idle unless I keep on the gas, and sputters and jumps while driving jerking the truck around. I troubleshooted for around 8 hours yesterday, checking all the vacuum lines, ignition, fuel pressure, sprayed starter fluid all around the intake checking for leaks, made sure all the sensors were plugged in from the swap, I literally cannot figure out what it is. The only thing I can think of is the crank position sensor. Would be purely coincidental, but possible. What do you guys think?? Can't wrap my brain around this.

Also, forgot to mention my power steering doesn't work for some reason, and it idles perfect for 5 seconds, then starts sputtering and dying out.

 

[Mark_88]

The crank position sensor, from what I understand, would cause the engine to not even start if damaged.

If it runs smoothly on first starting but then goes into the spasms shortly thereafter I would suspect fuel starvation, possible choke or Throttle Position Sensor because it can't tell how much fuel to dump in or doesn't recognize the engine is at operating temps.

I would assume that you've had to use the FI from the original motor including the TB and all sensors. If you haven't already done so, check the TPS...clean it as needed...

Does the throttle plate actually open when you move the accelerator? You can check that by removing the plastic/rubber air hose and have a look inside.

Almost sounds like the choke is closed, cutting off air supply...usually has a slightly higher idle under these conditions.

I know RonD posted a diagnostic for the Temp sensor (ECT) and that may be at fault...like a wire has come off or otherwise not connecting properly to feedback to the computer...

Try searching this section for "temp sensor"...I'm sure it was a recent post.

 

[JoshErnst1074]

The butterfly valve works, I used the new fuel rail with new injectors and they are definitely spraying fuel, I thought it was fuel starvation too. But it's hard to tell. I'm wondering if the 95 motor injectors are different than the 89. Even so, the truck ran perfect for 3 hours and now it's not. Which is weird.

 

[Mark_88]

Yeah, all things considered, it is weird.

I found this on the ECT...there is a post by RonD about how the choke works on FI systems...its about a no start issue but the symptoms do sound like "choke"...give it a look and check that...

The injectors are different...I think the 89s were 14# and they changed to 16# as some point...someone posted a link for the injector specs...what colour where the rings on the 95 injectors? I know 98 had orange rings because that is what is on my 96 (with a 98 2.5).

 

[JoshErnst1074]

I checked out ronD couldn't find anything on chokes for some reason. This is confusing.

 

[JoshErnst1074]

Found out the fuel line quick disconnects weren't on all the way causing a barely visible leak. Thinkin this might be the problem.

 

[Mark_88]

Yes, could very well be...but nothing like testing it...eh!

Use the advanced search options...type in user name on the left and issue key words on the right...I actually found it a couple of hours ago and was going to post the link but somehow got sidetracked...usually happens when it's too cold out to go play with my truck...

EDIT:

OK, I know I posted this somewhere because I also explained that it was about a 2.5 and cold starting...but, anyway...couple of posts down he mentions the effect of a wonky ECT (temp sensor) so it will give you an idea about the "choking action"...

but I'd try driving it if you reseated the fuel lines and there is no leak...

 

[Kenneth S]

A crank position sensor can act up, I found one that would quit working once the engine got warm, let it cool down it fired it up got warm then quit. The next time it did it I dumped some water on it right away, and it worked without having to wait for it cool off. Replaced the cps, no more problems, so the cps can cause intermittent problems.

 

[JoshErnst1074]

So I checked the fuel pressure while running, And without. Both are 22 psi when it should be closer to 40. You could hear he fuel pump turning on and off on and off. Which was making the engine rev and die over and over again. I replaced the fuel pump relay, and that stopped, but still idled rough and eventually turned off. Still only 22 psi. Is there anything else that could cause this besides the fuel pump? That's my last resort because that's not fun to replace. This seems like all coincidence because I literally just put a newer motor in. But I can't think of anything else. This is such a weird problem. Don't think it's the crank position sensor because I'm still only getting 22 psi with the motor off. Without vacuum, and without the CPS working yet. Would be really coincidental if the fuel pump went out just after changing engines.

 

[Mark_88]

The fuel pump is much easier to do if you remove the bed. Takes about an hour to remove the bed and then the fuel pump is right there...might want to have a shop vac handy and a hose...when I pulled the bed on my 96 and 92 the sending unit was covered in crap that falls down between the bed and the cab...

On my 88 I put a piece of vinyl floor covering over the sending unit about 5 years ago and it is still there...last time I checked...covers the sending unit nicely~!

 

[JoshErnst1074]

Yeah man I really hope this is the problem. I'm tired of trying to figure this out.

 

[Kenneth S]

Would be really coincidental if the fuel pump went out just after changing engines.

When it comes to electrical components anything can happen with them at given time. X2 on removing the bed to get to the fuel pump, it makes what can be a miserable job so much easier!

 

[JoshErnst1074]

I figured it out! It wasn't until after I turned the headlights on I noticed the truck ran fine with the headlights on. As soon as I turned them off, it wanted to die. It was getting way too much voltage and when I increased the load (turning the headlights on) it ran fine. So that only left the voltage regulator. Replaced it and now the truck runs fine after replacing everything else on it of course lol.

 

[Mark_88]

Cool...thanks for the update...never would have suspected the VR for this, but...learn something new every day.

You can test the VR through the battery...when running it should be around 13 V...when not running around 12 volts...if it goes above 13 volts and stays there while running you can suspect the VR...

Anyway...for future reference...

 

[4b316]

22 lbs isn't no wheres near enough for it to run good,I,d replace the pump even for peace of mind.Did you change the whole wiring harness or how did you change over the crank sensor?Intake?Cam sensor?Use the 95 head?