2.3L ('83-'97) Power problem

[RWB65]

Hello, I’ve gat a 97 2wd ext cab 2.3 Lima 5spd. Taking off from a stop, I have no power. I have to rev the motor to about 3000 to go. The motor has 188000 miles. Passes emissions with great numbers. I have replaced plugs, wires, coils, MAF, tps, temp sensor, ecm.
Timing Belt. Also replace fuel pump, filter. When engine is cool, the problem is not bad. When hot, it gets worse, when I turn on AC, really bad! Over the winter the temps were cool. Seemed to be ok. Tried coming thru Houston rush hour last week. A couple of times I didn’t think i could get it to roll
i hung a timing lite on it for fun. (I know timing is not adjustable.) idle is 10 btc crack the throttle open it goes 7 ATC, and doesn’t recover for awhile. At 3000 I’ve only got 16-18 BTC (no wonder i cant take off!!) any ideas what else i can try. I appreciate any help. 40 years as a tech, I’m lost on this one!

 

[Dirtman]

First thing I would suspect given you have replaced the timing belt is that it is not properly timed. From personal experience it's a bit of a pain to get all 3 gears lined up and quite easy to release the tension and have the belt skip a tooth or more on one of the pullies. The ignition timing is done by the computer but relies on your initial belt timing. Have one of those pullies off the mark and its all crap.

 

[scotts90ranger]

That's a lot of expensive parts to throw at it... My '97 is kinda doggy from a stop until you get it revved up a little then it's fine in all the gears... mine is a base model with no tach so no real good idea on what it's turning...

The MAF is part of the equation, but since it runs better cold I would suspect the pre cat oxygen sensor, it'll be my first go to...

but yes, I would double check the timing marks, the aux pulley does do stuff on the '95-01 Lima's unlike the '89-94... I got mine right the first try, but I just changed the belt and had an idea on where the marks were supposed to be

 

[89Twincharge]

Ignition control modules can malfunction when they get hot, as well as above posts causing low end power...

 

[RWB65]

Thank you for the responses. Timing is dead on (checked multiple times) I had considered O2s. It’s the only sensors I haven’t replace. I don’t think i mentioned. Ive never had a CEL come on and there are no codes.

 

[RWB65]

89twin. a different computer. Nothing changed.

 

[RWB65]

I tried a different computer

 

[RWB65]

I had a guy on another forum tell me to check the knock sensor. I would if it had one because that is what it feels like. ...more info like i said previous. This happens when its hot. I can drive highway speed its ok. When I’m stuck in traffic on a 90 plus day is when it acts up.

 

[RWB65]

It’s driving me crazy, and it’s a short trip!

 

[scotts90ranger]

Throwing parts at it is a hard way to diagnose stuff and rarely fixes the problem, sometimes introduces more issues or questions...

Ok, that's a different way of putting it, I thought you just meant it was doggy when it was warmed up coolant temp wise, hot day adds another dimension, but I still point my finger at pre cat O2 sensor (post cat doesn't change fueling or anything you would notice driving). The air fuel ratio is a complex algorithm with several variables but mainly the MAF reading and engine speed for the base table, then there's multipliers based on coolant temperature and air temperature (I think that reading comes from the MAF, I'm more used to speed density and not up on MAF Ford's) then another based on what the O2 sensor is reading compared to what it thinks it is supposed to do. Now spark advance on the other hand is likely simpler, base table should be based on MAF and engine speed with an offset based on air temperature if I had to guess.

If the air temp sensor isn't in the MAF (I haven't looked in a while, but I think there is a sensor near the MAF in the intake tube and I think it is 2 wire like a temp sensor would be) I would try one of those along with the pre cat O2... come to think of it my '97 was especially doggy today when it was 95F out...

 

[RWB65]

Scott’s 90 ranger. Thanks for the reply. I’ve been thinking about the pre O2. I’ve just never seen one do this. 40 years working on VW. I know how sensors react on VR6 motors. I will get some O2’s next week. One more thought. I haven’t watched the scanner when I’m stuck in traffic. Idle, low airflow over radiator. I wonder if it’s just getting to hot. Guage doesn’t show that. But we know how accurate stock gauges are. When I had that issue in Houston rush hour. ( and doggie was not the word. It’d been faster if I got out and pushed!) after I got moving again it was ok. installed new fan clutch awhile back. Thought about putting a aux pusher fan in front. Thoughts? Thanks

 

[RWB65]

Does anyone make a double core radiator for this.

 

[scotts90ranger]

The easiest way to put in a bigger radiator is switch to a V6 radiator, that just switches the top and bottom hoses to the other sides, if you cut the top hose in half and put a copper 45 degree elbow that works, then I'm not sure on the lower in the newer ones, on my '90 I used a '86 Thunderbird Turbocoupe lower hose and it fit decent...

I doubt it's coolant temp, it's probably air temp which putting a thicker radiator in would hurt, the air isn't moving stopped, that's why it gets better moving...

 

[89Twincharge]

89twin. a different computer. Nothing changed.

Not computer ignition control module...

 

[RWB65]

Hey Scott’s 90. I really appreciate your time. Did some more testing. I’ve got an old OTC scanner. You’re right it does seem to be related to IAT. Scanner readings idling w AC on. Everything is fine until IAT reaches above 130. Then timing events go weird. When you try to excelerate, timing goes to -8. Then eventually climbs. Put big fan on it coolant temp drops, IAT doesnt. Went to drive, got IAT under 130 started to return to normal. O2 readings normal thru all this. I’m going to try pre O2 next week. If you can noodle anything else, let me know. I really appreciate it.